Search

One of the hallmarks of twin pregnancies is the slower rate of fetal growth when compared with singleton pregnancies during the third trimester. The mechanisms underlying this phenomenon and whether it represents pathology or benign physiological adaptation are currently unclear. One important implication of these questions relates to the type growth charts that should be used by care providers to monitor growth of twin fetuses. If the slower growth represents pathology (ie, intrauterine growth restriction caused uteroplacental insufficiency), it would be preferable to use a singleton growth chart to identify a small twin fetus that is at risk for perinatal mortality and morbidity. If, however, the relative smallness of twins is the result of benign adaptive mechanisms, it is likely preferable to use a twin-based charts to avoid overdiagnosis of intrauterine growth restriction in twin pregnancies. In the current review, we addressed this question by describing the differences in fetal growth between twin and singleton pregnancies, reviewing the current knowledge regarding the mechanisms responsible for slower fetal growth in twins, summarizing available empirical evidence on the diagnostic accuracy of the 2 types of charts for intrauterine growth restriction in twin pregnancies, and addressing the question of whether uncomplicated dichorionic twins are at an increased risk for fetal death when compared with singleton fetuses. We identified a growing body of evidence that shows that the use of twin charts can reduce the proportion of twin fetuses identified with suspected intrauterine growth restriction by up to 8-fold and can lead to a diagnosis of intrauterine growth restriction that is more strongly associated with adverse perinatal outcomes and hypertensive disorders than a diagnosis of intrauterine growth restriction based on a singleton-based chart without compromising the detection of twin fetuses at risk for adverse outcomes caused by uteroplacental insufficiency. We further found that small for gestational age twins are less likely to experience adverse perinatal outcomes or to have evidence of uteroplacental insufficiency than small for gestational age singletons and that recent data question the longstanding view that uncomplicated dichorionic twins are at an increased risk for fetal death caused by placental insufficiency. Overall, it seems that, based on existing evidence, the of use twin charts is reasonable and may be preferred over the use of singleton charts when monitoring the growth of twin fetuses. Still, it is important to note that the available data have considerable limitations and are primarily derived from observational studies. Therefore, adequately-powered trials are likely needed to confirm the benefit of twin charts before their use is adopted by professional societies.

Mifepristone became available in Canada in 2017. Updated national guidelines recommend its off-label use for second/third-trimester medical abortion (STMA/TTMA) by labour induction. The objective of this study was to explore STMA/TTMA provision in Canada and the role of mifepristone.We conducted a national, cross-sectional, web-based, self-administered, anonymized survey, available in English and French. The survey was distributed through health professional organizations and recruited physicians who provided abortion care in 2019. We used a modified Dillman technique to maximize participation. The survey included sections on workforce and clinical care, including mifepristone use. We used R statistical software to produce descriptive statistics.Four hundred sixty-five clinicians responded to the survey, of whom 112 reported providing STMA and 63, TTMA, for a total of 115 respondents providing at least 1 of the 2 services. Two-thirds of respondents were general obstetrician-gynaecologists or family physicians and the remainder were maternal-fetal medicine subspecialists. The majority (64.7%) provided STMA/TTMA in an academic hospital, and 59.4% performed fewer than 5 STMAs (maximum 50) and 76.1%, fewer than 5 TTMA (maximum 15) in 2019. Fifty-nine percent of respondents reported having used mifepristone/misoprostol for STMA. Among mifepristone users, 48.6% used it for TTMA. Most required an indication beyond patient request to provide STMA/TTMA (82.1%/95.5%).STMA/TTMA care is provided by multiple (sub-) specialties, and mifepristone has not yet been universally implemented. Our results will inform knowledge translation activities aimed at facilitating collaboration between STMA/TTMA providers and health policy and service delivery leaders and will further increase mifepristone use for STMA/TTMA in Canada.

IntroductionSevere maternal morbidity (SMM)—an unexpected pregnancy-associated maternal outcome resulting in severe illness, prolonged hospitalisation or long-term disability—is recognised by many, as the preferred indicator of the quality of maternity care, especially in high-income countries. Obtaining comprehensive details on events and circumstances leading to SMM, obtained through maternity units, could complement data from large epidemiological studies and enable targeted interventions to improve maternal health. The aim of this study is to assess the feasibility of gathering such data from maternity units across Canadian provinces and territories, with the goal of establishing a national obstetric survey system for SMM in Canada.Methods and analysisWe propose a sequential explanatory mixed-methods study. We will first distribute a cross-sectional survey to leads of all maternity units across Canada to gather information on (1) Whether the unit has a system for reviewing SMM and the nature and format of this system, (2) Willingness to share anonymised data on SMM by direct entry using a web-based platform and (3) Respondents’ perception on the definition and leading causes of SMM at a local level. This will be followed by semistructured interviews with respondent groups defined a priori, to identify barriers and facilitators for data sharing. We will perform an integrated analysis to determine feasibility outcomes, a narrative description of barriers and facilitators for data-sharing and resource implications for data acquisition on an annual basis, and variations in top-5 causes of SMM.Ethics and disseminationThe study has been approved by the Mount Sinai and Hamilton Integrated Research Ethics Boards. The study findings will be presented at annual scientific meetings of the Society of Obstetricians and Gynaecologists of Canada, North American Society of Obstetric Medicine, and International Network of Obstetric Survey Systems and published in an open-access peer-reviewed Obstetrics and Gynaecology or General Internal Medicine journal.

Medically-indicated deliveries are common in twin pregnancies given the increased risk of various obstetric complications in twin compared to singleton pregnancies, mainly hypertensive disorders of pregnancy and foetal growth restriction. Due to the unique characteristics of twin pregnancies, the success rates and safety of labour induction may be different than in singleton pregnancies. However, while there are abundant data regarding induction of labour in singleton pregnancies, the efficacy and safety of labour induction in twin pregnancies have been far less studied. In the current manuscript we summarize available data on various aspects of labour induction in twin pregnancies including incidence, success rate, prognostic factors, safety and methods for labour induction in twins. This information may assist healthcare providers in counselling patients with twin pregnancies when labour induction is indicated.

Objective Recent World Health Organization (WHO) recommendations regarding uterotonics for the prevention of postpartum hemorrhage (PPH) state that carbetocin should be considered a first-line prophylactic agent for all births where its cost is comparable to other effective uterotonics. This study evaluated whether a room temperature stable formulation of carbetocin met this recommendation in a Canadian urban hospital setting. Methods A decision tree model was developed to assess the financial implications of replacing oxytocin with carbetocin as a first-line prophylactic agent for PPH prevention in a Greater Toronto Area (GTA) hospital. The analysis accounted for the mode of delivery, efficacies of carbetocin and oxytocin in PPH prevention, occurrence of PPH-related health outcomes, and health care resource costs for PPH interventions. Results This study found that a GTA hospital, with 3242 deliveries per year, could save over CAD $349 000 annually by switching to room temperature stable carbetocin for PPH prevention. Carbetocin was able to lower institution costs by reducing the use of health care resources for PPH management in low-risk and high-risk PPH patients. The cost-saving potential of carbetocin relative to oxytocin was largely attributed to its greater efficacy in preventing the consequences of PPH. Conclusion The use of room temperature stable carbetocin as a first-line prophylactic agent for PPH prevention meets WHO recommendations regarding uterotonics for PPH in a GTA hospital. The model from this study can be used to determine the financial impact of switching from oxytocin to carbetocin in other jurisdictions while diversifying a hospital's pool of PPH prophylactic agents.

Cerebro-placental ratio (CPR) is a doppler tool contributes to clinical decision-making in pregnancies affected by small for gestational age weight (SGA). Pregnancies affected by gestational diabetes mellitus (GDM) tend to have higher newborn weight, but greater risk of adverse perinatal outcomes. We hypothesized that in GDM-complicated-pregnancies CPR will be associated with adverse perinatal outcomes even in the absence of SGA.This prospective single-center cohort study included non-anomalous singleton pregnancies in women with GDM. Those with pre-pregnancy diabetes mellitus, hypertensive disorder or suspected SGA were excluded. Routine fetal sonographic assessment included CPR-defined as middle cerebral artery pulsatilty index/umbilical artery pulsatilty index. Masked CPR measurement closest to birth was used, classified as10th (normal) or ≤10th centile (low). Primary outcome was a composite, consisting of stillbirth, Caesarean birth due to abnormal fetal heart rate pattern, 5-minute Apgar7, cord arterial pH 7.0, hypoxic ischemic encephalopathy, or NICU admission24 hours.Of 281 participants, 24 (8.5%) had low CPR, at a mean gestational age of 36.3 weeks (IQR 34.0-37.4). Birthweight percentile was significantly lower among the low CPR group (35th [IQR 16-31] versus 60th [IQR 31-82]; P = .002). There was no statistically difference in the primary composite outcome between the groups (8.3% versus 7.0%, P = .68). Low CPR was significantly associated with a higher risk of neonatal hypoglycemia (adjusted odds ratio 3.2, 95% CI 1.2-8.3).In pregnancies affected by GDM, CPR ≤10th percentile was not associated with adverse perinatal outcome but was associated with neonatal hypoglycemia.

This study aimed at determining the proportion of women who receive antenatal corticosteroids (ACS) within the optimal time window before birth based on the indication for ACS, and to explore in more detail indications that are associated with suboptimal timing.A retrospective cohort study of all women who received ACS in a single tertiary center between 2014 and 2017. The primary outcome was an ACS-to-birth interval ≤ 7 days. Secondary outcomes were ACS-to-birth interval of ≤ 14 days, and the proportion women who received ACS but ultimately gave birth at term (≥ 37A total of 1261 women met the study criteria, of whom 401 (31.8%) and 569 (45.1%) received ACS within ≤ 7 days and ≤ 14 days before birth, respectively, and 203 (16.1%) ultimately gave birth at term. The proportion of women who received ACS within 7 days before birth was highest for women with preeclampsia (50.4%), and was lowest for women with an incidental finding of a short cervix (8.4%). In the subgroup of women with an incidental finding of a short cervix, the likelihood of optimal timing was not related to the magnitude of cervical shortening, history of preterm birth, multifetal gestation, presence of cervical funneling, or the presence of cervical cerclage.Over two-thirds of infants who are exposed to ACS do not get the maximal benefit from this intervention. The current study identified clinical indications for ACS that are associated with suboptimal timing of ACS where more research is needed to develop quantitative, indication-specific prediction models to guide the timing of ACS.

Objective To evaluate whether pregnancy outcomes associated with hypertensive disorders of pregnancy in twin pregnancies differ relatively from those in singleton pregnancy. Methods We conducted a retrospective, population-based cohort study of all women with a liveborn singleton or twin hospital birth in Ontario, Canada, between 2012 and 2019. Data were obtained from the Better Outcomes Registry & Network Ontario. Pregnancy outcomes were compared between women with and without hypertensive disorders of pregnancy in twin gestations, and separately in singleton gestations. Adjusted relative risks (aRRs) and 95% CIs were generated using modified Poisson regression and were compared between twins and singletons using relative risk ratios. Results Overall, 932,218 women met the study criteria, of whom 917,542 (98.4%) and 14,676 (1.6%) had singleton and twin gestations, respectively. The incidence of hypertensive disorders of pregnancy was higher in women with twin compared with singleton gestations (14.4% vs 6.4%, aRR 1.85 [1.76-1.94]). Hypertensive disorders of pregnancy were associated with certain adverse outcomes in singleton gestations only and with other adverse outcomes in both the singleton and twin gestations, but the aRR was lower in twins. For example, preterm birth before 37 weeks of gestation (singletons: 15.2% [hypertensive disorders of pregnancy] vs 5.4% [no hypertensive disorders of pregnancy], aRR 2.42; twins: 67.5% [hypertensive disorders of pregnancy] vs 50.4% [no hypertensive disorders of pregnancy], aRR 1.30) and neonatal respiratory morbidity (singletons: 16.3% [hypertensive disorders of pregnancy] vs 8.7% [no hypertensive disorders of pregnancy], aRR 1.50; twins: 39.8% [hypertensive disorders of pregnancy] vs 32.7% [no hypertensive disorders of pregnancy], aRR 1.13). These findings persisted in the subgroups of women with preeclampsia and early-onset preeclampsia. Conclusions Although the absolute risk of adverse maternal and neonatal outcomes is higher in twin compared with singleton pregnancies, the incremental risk of adverse outcomes associated with hypertensive disorders in twin pregnancies is lower than the incremental risk in singleton pregnancies. These findings may be attributed in part to the higher baseline risk of preterm birth and adverse maternal and perinatal outcomes in twin compared with singleton pregnancies.

We sought to describe temporal trends in hospital admissions for threatened preterm labor (TPTL) and to examine hospital admission duration among women delivered or discharged undelivered. We carried out a cohort study on all TPTL admissions among pregnancies with a live singleton fetus and intact membranes between 1999 and 2015 using the United States’ Healthcare Cost and Utilization Project-Nationwide Inpatient Sample. ICD-9 codes were used to identify women with TPTL. Duration of antenatal admission length of stay was calculated in days following admission to hospital until delivery (“Delivery Admission”) or undelivered discharge (“Observation Admission”). Analyses included evaluating trends of birth admissions over total admissions, identifying predictors of delivery using logistic regression, and measuring risk for delivery with increasing duration of antepartum hospitalization. Of 15,335,288 pregnancy admissions, 1,089,987 admissions were for TPTL, with 61.8% being ‘Delivery Admissions”. During the 16-year study period, overall rates of TPTL admissions declined with a rising proportion of admissions being “Delivery Admissions”. “Delivery Admissions” were more common among patients who were older, non-Caucasian, obese, or who had placental abruption. “Observation Admissions” were more common among admissions for antepartum hemorrhage or antepartum spotting. Among all “Delivery Admissions” for TPTL, 89% had delivered within 2 days, 7% delivered within 3–6 days, and 5% delivered beyond 6 days. Overall admissions for TPTL declined over the study period with increasing proportions being “Delivery Admissions”. Protocols taking into consideration declining risk of preterm birth among patients undelivered after 2 days may be helpful in reducing unnecessary prolonged observation admissions.

INTRODUCTION Since 2013, various guidelines for hypertension in pregnancy have been refined, no longer requiring proteinuria as a requisite criterion for preeclampsia. We aimed to evaluate the impact of the new definition on preterm birth (PTB) and adverse pregnancy outcomes. MATERIAL AND METHODS Women delivering in Ontario between April 2012 and November 2016 were included. Delivery

To investigate the current practices of maternal-fetal medicine (MFM) specialists regarding the prevention and management of preterm birth (PTB) in twin pregnancies.This was a cross-sectional study of Canadian MFM specialists. Participants responded to an anonymous survey regarding the prevention and management of PTB in twins, including lifestyle and gestational weight gain recommendations, cervical length screening, PTB prevention, and labour and delivery practices.Of 137 MFM specialists surveyed, 95 (69%) responded. Most MFM specialists recommend against activity restriction (77.9%), avoidance of sexual activity (96.7%), routine progesterone (97.8%), routine prophylactic cerclage (98.9%), and routine administration of antenatal corticosteroids (95.6%). There were considerable inconsistencies with respect to gestational weight gain management. Despite lack of support by guidelines, most MFM specialists reported using routine cervical length screening (97.8%) and progesterone for short cervix (92.3%). Over half (52.7%) of MFM specialists recommend cervical cerclage when the cervix is15mm. In cases of PTB, most MFM specialists recommend vaginal delivery when twins are in vertex presentation (63%-75%). MFM specialists are less likely to recommend vaginal delivery when twin B is non-vertex (35%-41%).There is a considerable variation among MFM specialists regarding the prevention and management of PTB in twins, and the practice of many MFM specialists differs from that recommended by professional societies' guidelines. These findings underscore the necessity for high-quality studies and up-to-date recommendations.

OBJECTIVE We aimed to quantify the risk of future maternal type 2 diabetes mellitus (T2DM) in women with gestational diabetes mellitus (GDM) based on the type and number of abnormal 75-g oral glucose tolerance test (OGTT) values and the diagnostic criteria used for the diagnosis of GDM. RESEARCH DESIGN AND METHODS We conducted a population-based retrospective cohort study of all nulliparous women with a live singleton birth who underwent testing for GDM using a 75-g OGTT in Ontario, Canada (2007–2017). We estimated the incidence rate (per 1,000 person-years), overall risk (expressed as adjusted hazard ratio [aHR]), and risk at 5 years after the index pregnancy of future maternal T2DM. Estimates were stratified by the type and number of abnormal OGTT values, as well as by the diagnostic criteria for GDM (Diabetes Canada [DC] vs. International Association of the Diabetes and Pregnancy Study Groups [IADPSG] criteria). RESULTS A total of 55,361 women met the study criteria. The median duration of follow-up was 4.4 (interquartile range 2.8–6.3; maximum 10.3) years. Using women without GDM as reference (incidence rate 2.18 per 1,000 person-years), women with GDM were at an increased risk of future T2DM; this risk was greater when using the DC compared with the IADPSG criteria (incidence rate 18.74 [95% CI 17.58–19.90] vs. 14.07 [95% CI 13.24–14.91] per 1,000 person-years, respectively). The risk of future maternal T2DM increased with the number of abnormal OGTT values and was highest for women with three abnormal values (incidence rate 49.93 per 1,000 person-years; aHR 24.57 [95% CI 21.26–28.39]). The risk of future T2DM was also affected by the type of OGTT abnormality: women with an abnormal fasting value had the greatest risk, whereas women with an abnormal 2-h value had the lowest risk (aHR 14.09 [95% CI 12.46–15.93] vs. 9.22 [95% CI 8.19–10.37], respectively). Similar findings to those described above were observed when the risk of T2DM at a fixed time point of 5 years after the index pregnancy was considered as the outcome of interest. CONCLUSIONS In women with GDM, individualized information regarding the future risk of T2DM can be provided based on the type and number of abnormal OGTT values, as well as the diagnostic criteria used for the diagnosis of GDM.

Context The optimal 50 g-glucose challenge test (GCT) cutoff for the diagnosis of gestational diabetes mellitus (GDM) in twin pregnancies is unknown. Objective This work aimed to explore the screening accuracy of the 50 g-GCT and its correlation with the risk of large for gestational age (LGA) newborn in twin compared to singleton pregnancies. A population-based retrospective cohort study (2007-2017) was conducted in Ontario, Canada. Participants included patients with a singleton (n = 546 892 [98.4%]) or twin (n = 8832 [1.6%]) birth who underwent screening for GDM using the 50 g-GCT. Methods We compared the screening accuracy, risk of GDM, and risk of LGA between twin and singleton pregnancies using various 50 g-GCT cutoffs. Results For any given 50 g-GCT result, the probability of GDM was higher (P = .0.007), whereas the probability of LGA was considerably lower in the twin compared with the singleton group, even when a twin-specific growth chart was used to diagnose LGA in the twin group (P Conclusion The screening performance of the 50 g-GCT for GDM and its correlation with LGA differ between twin and singleton pregnancies.

To determine the feasibility of rescue cerclage and amnioreduction at advanced cervical dilation or gestational age.We present a retrospective case series of women who underwent rescue cerclage at either an advanced gestational age (24 + 0 to 24 + 6 weeks) or cervical dilation (≥4 cm), with a subset undergoing amnioreduction prior to cerclage placement.Nine women were included and amnioreduction was performed in 7 (78%). A bi-modal distribution of obstetric outcomes was observed, with 5 (56%) women delivering ≥34 weeks gestation, 3 (33%) of which delivered at term. Two (22%) women experienced intra-operative rupture of membranes and subsequent perinatal deaths. Two (22%) women delivered extremely premature, with one resulting in infant death.Our data show that rescue cerclage with amnioreduction may be successful at advanced gestational ages or cervical dilations, suggesting that these women should be included in prospective studies to better establish the efficacy and safety of this procedure.

Objective: The aim of the current study was to identify the optimal cutoff that should define discordance in dichorionic twin gestations through correlation with abnormal placental pathology as a specific measure of fetal growth restriction of the smaller twin. Methods: We performed a retrospective cohort study of all women with dichorionic twin pregnancies who gave birth in a single center between 2002 and 2015. We investigated the association between the level of growth discordance and maternal vascular malperfusion (MVM) pathology in the placenta of the smaller twin, with and without adjustment for whether the smaller twin is small for gestational age (SGA). Results: A total of 1,198 women with dichorionic twin gestation met the study criteria. The rate of MVM pathology in the placenta of the smaller twin increased with the level of discordance and was most obvious for discordance ≥25% (rate of MVM 12.0% compared with 2.8% in cases with discordance Conclusion: Our findings suggest that discordant growth in dichorionic twins should raise the concern of fetal growth restriction of the smaller twin, irrespective of whether the smaller twin is SGA, only when the discordance s ≥25%. The association of lower levels of discordance with abnormal placental pathology is mainly driven by the confounding effect of SGA of the smaller twin.

IMPORTANCE: There is limited comparative epidemiological evidence on outcomes associated with COVID-19 vaccination during pregnancy; monitoring pregnancy outcomes in large populations is required. OBJECTIVE: To evaluate peripartum outcomes following COVID-19 vaccination during pregnancy. DESIGN, SETTING, AND PARTICIPANTS: Population-based retrospective cohort study in Ontario, Canada, using a birth registry linked with the provincial COVID-19 immunization database. All births between December 14, 2020, and September 30, 2021, were included. EXPOSURES: COVID-19 vaccination during pregnancy, COVID-19 vaccination after pregnancy, and no vaccination. MAIN OUTCOMES AND MEASURES: Postpartum hemorrhage, chorioamnionitis, cesarean delivery (overall and emergency cesarean delivery), admission to neonatal intensive care unit (NICU), and low newborn 5-minute Apgar score (

OBJECTIVE: First, to evaluate the risks of stillbirth and neonatal death by gestational age in twin pregnancies with different levels of growth discordance and in relation to small for gestational age (SGA), and on this basis to establish optimal gestational ages for delivery. Second, to compare these optimal gestational ages with previously established optimal delivery timing for twin pregnancies not complicated by fetal growth restriction, which, in a previous individual patient meta-analysis, was calculated at 37 0/7 weeks of gestation for dichorionic pregnancies and 36 0/7 weeks for monochorionic pregnancies.DATA SOURCES: A search of MEDLINE, EMBASE, ClinicalTrials.gov, and Ovid between 2015 and 2018 was performed of cohort studies reporting risks of stillbirth and neonatal death in twin pregnancies from 32 to 41 weeks of gestation. Studies from a previous meta-analysis using a similar search strategy (from inception to 2015) were combined. Women with monoamniotic twin pregnancies were excluded.METHODS OF STUDY SELECTION: Overall, of 57 eligible studies, 20 cohort studies that contributed original data reporting on 7,474 dichorionic and 2,281 monochorionic twin pairs.TABULATION, INTEGRATION, AND RESULTS: We performed an individual participant data meta-analysis to calculate the risk of perinatal death (risk difference between prospective stillbirth and neonatal death) per gestational week. Analyses were stratified by chorionicity, levels of growth discordance, and presence of SGA in one or both twins. For both dichorionic and monochorionic twins, the absolute risks of stillbirth and neonatal death were higher when one or both twins were SGA and increased with greater levels of growth discordance. Regardless of level of growth discordance and birth weight, perinatal risk balanced between 36 0/7-6/7 and 37 0/7-6/7 weeks of gestation in both dichorionic and monochorionic twin pregnancies, with likely higher risk of stillbirth than neonatal death from 37 0/7-6/7 weeks onward.CONCLUSION: Growth discordance or SGA is associated with higher absolute risks of stillbirth and neonatal death. However, balancing these two risks, we did not find evidence that the optimal timing of delivery is changed by the presence of growth disorders alone.SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42018090866.

To evaluate the effect of the choice growth chart and threshold used to define small for gestational age (SGA) on the predictive value of SGA for placenta-related or unexplained antepartum stillbirth.A retrospective cohort study of all women with a singleton pregnancy who gave birth 24 week gestation in a single center (2000-2016). The exposure of interest was SGA, defined as birth weight 10th or 25th centile according to three fetal growth charts (Hadlock et al., Radiology 181:129-133, 1991; intergrowth-21st (IG21), WHO 2017, and a Canadian birthweight-based reference-Kramer et al., Pediatrics 108:E35, 2001). The outcome of interest was antepartum stillbirth due to placental dysfunction or unknown etiology. Cases of stillbirth attributed to other specific etiologies were excluded.A total of 49,458 women were included in the cohort. There were 103 (0.21%) cases of stillbirth due to placental dysfunction or unknown etiology. For cases in the early stillbirth cluster (≤ 30 weeks), the detection rate was high and was similar for the three ultrasound-based fetal growth charts of Hadlock, IG21, and WHO (range 83.3-87.0%). In contrast, the detection rate of SGA for cases in the late stillbirth cluster ( 30 weeks) was low, being highest for WHO and Hadlock (36.7% and 34.7%, respectively), and lowest for IG21 (18.4%). Using a threshold of the 25th centile increased the detection rate for stillbirth by approximately 15-20% compared with that achieved by the 10th centile cutoff.At 30 week gestation, the Hadlock or WHO fetal growth charts provided the best balance between detection rate and false positive rate for stillbirth.

Objectives To evaluate the utility of ultrasound markers in the management of pregnancies complicated by preterm prelabor rupture of membranes (PPROM) between 23 + 0 and 33 + 6 weeks' gestation, and to assess the ability of ultrasound markers to predict adverse neonatal outcomes. Methods This was a retrospective cohort study of all patients with PPROM between 23 + 0 and 33 + 6 weeks' gestation and latency period (PPROM to delivery) > 48 h, who delivered before 34 weeks' gestation at a tertiary referral center between 2005 and 2017. All patients underwent a non-stress test daily and an ultrasound scan twice a week for assessment of amniotic fluid volume, biophysical profile (BPP) and umbilical artery (UA) pulsatility index (PI). In patients with suspected fetal growth restriction, fetal middle cerebral artery (MCA)-PI was also assessed and the cerebroplacental ratio (CPR) calculated. The last ultrasound examination performed prior to delivery was analyzed. We compared the characteristics and outcomes between women who were delivered owing to clinical suspicion of chorioamnionitis and those who were not delivered for this indication. The primary objective was to evaluate the utility of ultrasound in the management of patients with PPROM. The secondary objective was to assess the diagnostic performance of ultrasound markers (BPP score 95th percentile, MCA-PI Results A total of 504 women were included in the study, comprising 120 with suspected chorioamnionitis and 384 without. Women with suspected chorioamnionitis, compared with those without, were less likely to be nulliparous (34.2% vs 45.3%; P = 0.03) and more likely to have fever (50.8% vs 2.6%; P 95th percentile was similar between the two groups. There was a higher incidence of composite adverse neonatal outcome in the group with suspected chorioamnionitis than in the group without (78.3% vs 64.3%, respectively; P = 0.004). However, on logistic regression analysis, none of the ultrasound markers evaluated was found to be associated with chorioamnionitis or composite adverse neonatal outcome, and they all had a poor diagnostic performance for the prediction of chorioamnionitis and composite adverse neonatal outcome. Conclusions Commonly used ultrasound markers in pregnancies complicated by PPROM were similar between women delivered for suspected chorioamnionitis and those delivered for other indications, and performed poorly in predicting composite adverse neonatal outcome. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Oxytocin is a commonly used drug in the labor and delivery unit. There are wide variations in oxytocin use between countries and medical centers, which may reflect the lack of structured guidelines. The aim of our study was to evaluate the need of oxytocin checklist in labor and delivery unit, while assessing the management of oxytocin with and without such a checklist. This study was conducted in a single, university-affiliated medical center in two phases: before and after the implementation of an oxytocin checklist in the labor and delivery unit (2016–2017). Six experts reviewed cardiotocographs of deliveries performed in an urgent Cesarean delivery due to non-reassuring fetal heart rate, after completing at least 4 h of oxytocin infusion for induction or augmentation of labor. The experts included three obstetricians, a midwife, and two obstetrical expert nurses, who were tasked to conclude whether oxytocin was managed properly or not. Each case was reviewed by two reviewers separately. A total of 100 cases were reviewed; 50 before the oxytocin checklist implementation, and 50 after that implementation. We did not find a difference in the reviewers' assessment of oxytocin management before and after the institutional implementation of the checklist. Additionally, there were significant inconsistencies and inter-observer variations in their assessment before and after the checklist implementation. The implementation of an institutional oxytocin checklist did not affect expert assessment of the use of oxytocin in labor.

Objective The purpose of this study was to determine the point prevalence of low back pain (LBP), pelvic girdle pain (PGP), and/or combination pain (COMBO pain) and period prevalence (presence or absence of any of those pains), as well as to identify risk factors at 1, 3, and 6 months postpartum in a Canadian population. Methods Participants from a previous pregnancy study participated in a postpartum survey administered over the telephone at 1, 3, and 6 months following delivery. The survey included questions about LBP, PGP, or COMBO pain during the postpartum period, as well as questions related to risk factors (Canadian Task Force Classification II-3). Results At 1, 3, and 6 months postpartum, responses from 46, 58, and 64 participants, respectively, demonstrated that 15%–21% of women experienced LBP and up to 4% of women experienced COMBO pain (point prevalence). At no time point was PGP reported to occur alone. Period prevalence of back pain for the participants returned to pre-pregnancy levels at each time point. Back pain during pregnancy was the only risk factor identified for back pain at 3 and 6 months postpartum. Conclusion This study demonstrated that 76% to 80% of respondents were pain free at 1, 3, and 6 months postpartum. Pregnancy-related back pain was the only risk factor associated with postpartum-related pain at the 1 to 3 and 3 to 6 month time interval. Identification of site-specific postpartum-related back pain may assist in determination of management and treatment plans for this population.

To determine the rate of sonographic placental markers and their predictive value for preeclampsia and fetal growth restriction in women with chronic kidney disease (CKD).A retrospective cohort study of women with CKD followed at a tertiary referral center between 2016 and 2019 (n = 86). All women underwent 2nd trimester sonographic placental examinations that included assessment of placental morphology, umbilical cord, and uterine artery Doppler. Continuous placental markers were converted to multiples on medians (MoM).Predictive value of sonographic markers for preeclampsia and birthweight 10th percentile.Women in the cohort had a high rate of preeclampsia (24.4%), birthweight 10th% (26.7%), and preterm birth (30.2%). The most important markers were placental volume and uterine artery Doppler: the risk of preeclampsia was elevated in women with low placental volume (51.7% vs. 10.9%; OR = 8.79 [2.70-28.59] for preeclampsia; and 40.0% vs. 9.1%; OR = 6.67 [1.85-24.04] for preterm preeclampsia), and in women with bilateral uterine artery notching (62.5% vs. 20.8%; OR = 6.35 [1.37-29.45] for preeclampsia; and 62.5% vs. 10.4%; OR = 14.38 [1.29-71.75] for preterm preeclampsia). The combination of both markers had the strongest predictive value for preeclampsia (positive likelihood ratio = 8.25 [6.84-9.95]). Low placental volume and bilateral uterine notching were also associated with birthweight 10th percentile.A 2nd-trimester sonographic placental study can identify a subgroup of women with CKD who are at most risk of preeclampsia and fetal growth restriction. Such data may inform their subsequent perinatal care and assist care providers in the often challenging distinction between preeclampsia flare of underlying CKD.

We retrospectively included women with abnormal FTS analytes and compared outcomes between those with elevated and normal UtA-PI. Out of 582 women with abnormal FTS analytes, 65 (11.2%) had elevated UtA-PI. Neonates of women in this group had higher rates of birth weight3rd, 5th, and 10th percentile. The area under the ROC curve for predicting FGR10th percentile by UtA-PI was 0.584, for FGR5th percentile 0.593, and for FGR3rd percentile 0.720. In women with abnormal FTS, elevated UtA-PI is associated with higher rates of FGR, but its predictability is moderate-to-poor.

Background Skin-to-skin contact between mother and infant immediately after birth is recommended regardless of delivery method; however, it is less common after cesarean delivery. We aimed to describe and compare women's experiences of cesarean birth with and without skin-to-skin contact at an urban tertiary care hospital. Methods In this hermeneutic phenomenologic study, we used semistructured telephone interviews from 2015 to 2018 to interview a convenience sample of women who delivered at term by scheduled skin-to-skin cesarean birth at an urban tertiary care hospital in Toronto, Ontario. Women were invited to participate if they had had a previous planned or unplanned cesarean birth and a scheduled skin-to-skin cesarean birth between 2013 and 2017. Participants were excluded if they had antenatally diagnosed conditions, they delivered before 37 weeks, they had general anesthesia, their condition was unstable at the time of surgery, a skin-to-skin cesarean birth was not possible or they declined skin-to-skin cesarean birth. Interviews were recorded, transcribed and analyzed by means of thematic analysis. Results Ten women were interviewed 1-19 months postpartum. Four central themes emerged: support for skin-to-skin cesarean birth (women feeling supported by their families and health care providers); control (participants experiencing greater control during their skin-to-skin cesarean birth); connection with the infant, which enabled women to be active participants in their delivery, enhanced bonding and intimacy, facilitated breastfeeding and bolstered confidence during early parenthood; and logistic considerations, with participants recognizing that skin-to-skin cesarean birth required additional resources. Interpretation These findings refine what is known about skin-to-skin cesarean birth and provide a critical perspective, that of mothers. They support the transformation of traditional operating room dynamics to a more patient-centred environment.

Umbilical cord arterial and venous blood gas values reflect the acid-base balance status of a newborn at birth. Derangement in these values has been linked to poor neonatal outcomes in term and late preterm neonates; however, the utility of these values in preterm neonates of29 weeks' gestation is unclear.This study aimed to determine the associations of umbilical cord arterial and venous blood gas values with neonatal mortality and severe neurologic injury in extremely preterm neonates and to identify the cutoff values associated with 2.5-fold increases or decreases in the posttest probabilities of outcomes.This was a retrospective cohort study of neonates who were born at 23+0 to 28+6 weeks' gestation between January 1, 2018 and December 31, 2019, and who were admitted to neonatal units in Canada.Various cut-offs of umbilical cord blood gas values and lactate values were studied.The main outcomes were mortality before discharge from the neonatal unit and severe neurologic injury defined as grade 3 or 4 periventricular or intraventricular hemorrhage or periventricular leukomalacia. The outcome rates were calculated for various cutoff values of umbilical cord blood gas parameters and were adjusted for birthweight, gestational age, sex, and multiple births. Likelihood ratios were calculated to derive posttest probabilities.A total of 1040 and 1217 neonates had analyzable umbilical cord arterial and venous blood gas values, respectively. In the cohort, the mean (standard deviation) gestational age was 26.5 (1.5) weeks, the mean birthweight was 936 (215) g, the prevalence of mortality was 10% (105/1040), and the prevalence of severe neurologic injury was 9% (92/1016). An umbilical cord arterial pH of ≤7.1 and base excess of ≤-12 mmol/L were associated with2.5-fold higher posttest probability of mortality, and an umbilical cord arterial or venous lactate value of3 was associated with a 2.5-fold lower posttest probability of mortality. An umbilical cord arterial lactate value of3 was associated with a lower posttest probability of severe neurological injury.In preterm neonates of29 weeks' gestation, low umbilical cord arterial pH and high umbilical cord arterial base excess values were associated with a clinically important increase in the posttest probability of mortality, whereas low umbilical cord arterial or venous lactate values were associated with a decrease in the posttest probability of mortality.

The screening accuracy of the 50 g-glucose challenge test (50 g-GCT) for gestational diabetes (GDM) has been described in singleton pregnancies. Given the physiologic differences and greater increase in insulin resistance in twin compared with singleton pregnancies, the performance of the 50 g-GCT in twin pregnancies may differ.To perform a systematic review on the screening performance of the 50 g-GCT for gestational diabetes in twin pregnancies.Ovid Medline, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL).We included randomized controlled trials or cohort studies that evaluated the screening accuracy of the 50 g-GCT for GDM in twin pregnancies using the two-step approach. The primary outcome was the positive predictive value of the 50 g-GCT for GDM using the 140 mg/dL (7.8 mmol/L) threshold.Methodological quality of included studies was assessed using the QUADAS-2 tool. The positive predictive value (PPV) was pooled for studies that used similar test characteristics.From 2044 citations, 7 retrospective cohort studies with a total of 55,597 participants were included (6.5% twins and 93.5% singletons). The majority of studies evaluated a 50-g GCT cutoff point of 140 mg/dL. The pooled PPV for a threshold of 140 mg/dL (7.8 mmol/L) for twins was 22.58% (95% CI: 0.1912-0.2647,The PPV of 50 g-GCT for GDM in twin pregnancies when using a threshold of 140 mg/dL (7.8 mmol/L) is approximately 23%. There is currently no data on the sensitivity and specificity of the 50 g-GCT in twins.

Lateral placentation may compromise placental perfusion, and we aimed to assess whether it impacts pregnancy outcomes. This single-center retrospective study included 1203 singleton pregnancies, categorized into two groups according to placental location. Women with lateral placenta had significantly higher risk of preterm birth

ObjectiveTo assess the risk of preterm birth, small for gestational age at birth, and stillbirth after covid-19 vaccination during pregnancy.DesignPopulation based retrospective cohort study.SettingOntario, Canada, 1 May to 31 December 2021.ParticipantsAll liveborn and stillborn infants from pregnancies conceived at least 42 weeks before the end of the study period and with gestational age ≥20 weeks or birth weight ≥500 g.Main outcome measuresUsing Cox regression, hazard ratios and 95% confidence intervals were estimated for preterm birth before 37 weeks (overall and spontaneous preterm birth), very preterm birth (ResultsAmong 85 162 births, 43 099 (50.6%) occurred in individuals who received one dose or more of a covid-19 vaccine during pregnancy—42 979 (99.7%) received an mRNA vaccine. Vaccination during pregnancy was not associated with any increased risk of overall preterm birth (6.5% among vaccinatedv6.9% among unvaccinated; adjusted hazard ratio 1.02, 95% confidence interval 0.96 to 1.08), spontaneous preterm birth (3.7%v4.4%; 0.96, 0.90 to 1.03), or very preterm birth (0.59%v0.89%; 0.80, 0.67 to 0.95). No increase was found in risk of small for gestational age at birth (9.1%v9.2%; 0.98, 0.93 to 1.03) or stillbirth (0.25%v0.44%; 0.65, 0.51 to 0.84). Findings were similar by trimester of vaccination, mRNA vaccine product, and number of doses received during pregnancy.ConclusionThe findings suggest that vaccination against covid-19 during pregnancy is not associated with a higher risk of preterm birth, small for gestational age at birth, or stillbirth.

Preterm premature rupture of membranes complicates approximately 3% of pregnancies. Currently, in the absence of chorioamnionitis or placental abruption, expectant management, including antenatal steroids for lung maturation and prophylactic antibiotic treatment, is recommended. The benefits of individualized management have not been adequately explored.This study aimed to compare the impact of 2 different management strategies of preterm premature rupture of membranes in 2 tertiary obstetrical centers on latency of7 days, latency to birth, chorioamnionitis, funisitis, and short-term adverse maternal and neonatal outcomes.This was a multicenter retrospective study of women with singleton pregnancies with preterm premature rupture of membranes from 23 0/7 to 33 6/7 weeks of gestation between 2014 and 2018 and undelivered within 24 hours after hospital admission managed at Sunnybrook Health Sciences Center, Toronto, Canada (standard management group), and BCNatal (Hospital Clínic of Barcelona and Hospital Sant Joan de Déu Barcelona), Barcelona, Spain (individualized management group), following local protocols. The standard management group received similar management for all patients, which included a standard antibiotic regimen and routine maternal and fetal surveillance, whereas the individualized management group received personalized management on the basis of amniocentesis at hospital admission (if possible), to rule out microbial invasion of the amniotic cavity and targeted treatment. The exclusion criteria were cervical dilatation2 cm, active labor, contraindications to expectant management (acute chorioamnionitis, placental abruption, or abnormal fetal tracing), and major fetal anomalies. The primary outcome was latency of7 days, and the secondary outcomes included latency to birth, chorioamnionitis, and short-term adverse maternal and neonatal outcomes. Statistical comparisons between groups were conducted with propensity score weighting.A total of 513 pregnancies with preterm premature rupture of membranes were included in this study: 324 patients received standard management, and 189 patients received individualized management, wherein amniocentesis was performed in 112 cases (59.3%). After propensity score weighting, patients receiving individualized management had a higher latency of7 days (76.0% vs 41.6%; P.001) and latency to birth (18.1±14.7 vs 9.7±9.7 days; P.001). Although a higher rate of clinical chorioamnionitis was suspected in the individualized management group than the standard group (34.5% vs 22.0%; P.01), there was no difference between the groups in terms of histologic chorioamnionitis (67.2% vs 73.4%; P=.16), funisitis (57.6% vs 58.1%; P=.92), or composite infectious maternal outcomes (9.1% vs 7.9%; P=.64). Prolonged latency in the individualized management group was associated with a significant reduction of preterm birth at32 weeks of gestation (72.1% vs 90.5%; P.001), neonatal intensive care unit admission (75.6% vs 83.0%; P=.046), and neonatal respiratory support at 28 days of life (16.1% vs 26.1%; P.01) compared with that in the standard management group. Moreover, prolonged latency was not associated with neonatal severe morbidity at discharge (survival without severe morbidity, 80.4% vs 73.5%; P=.09).Individualized management of preterm premature rupture of membranes may prolong pregnancy and reduce preterm birth at32 weeks of gestation, the need for neonatal support, and neonatal intensive care unit admissions, without an increase in histologic chorioamnionitis, funisitis, neonatal infection-related morbidity, and short-term adverse maternal and neonatal outcomes.

Background: People whose singleton pregnancy is affected by hypertensive disorders of pregnancy (HDP) are at risk of future cardiovascular disease. It is unclear, however, whether this association can be extrapolated to twin pregnancies. We aimed to compare the association between HDP and future cardiovascular disease after twin and singleton pregnancies. Methods: We conducted a population-based retrospective cohort study that included nulliparous people in Ontario, Canada, 1992–2017. We compared the future risk of cardiovascular disease among pregnant people from the following 4 groups: those who delivered a singleton without HDP (referent) and with HDP, and those who delivered twins either with or without HDP. Results: The populations of the 4 groups were as follows: 1 431 651 pregnant people in the singleton birth without HDP group; 98 631 singleton birth with HDP; 21 046 twin birth without HDP; and 4283 twin birth with HDP. The median duration of follow-up was 13 (interquartile range 7–20) years. The incidence rate of cardiovascular disease was lowest among those with a singleton or twin birth without HDP (0.72 and 0.74 per 1000 person-years, respectively). Compared with people with a singleton birth without HDP, the risk of cardiovascular disease was highest among those with a singleton birth and HDP (1.47 per 1000 person-years; adjusted hazard ratio [HR] 1.81 [95% confidence interval (CI) 1.72–1.90]), followed by people with a twin pregnancy and HDP (1.07 per 1000 person-years; adjusted HR 1.36 [95% CI 1.04–1.77]). The risk of the primary outcome after a twin pregnancy with HDP was lower than that after a singleton pregnancy with HDP (adjusted HR 0.74 [95% CI 0.57–0.97]), when compared directly. Interpretation: In a twin pregnancy, HDP are weaker risk factors for postpartum cardiovascular disease than in a singleton pregnancy.

Both gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP) are common, and each are associated with adverse maternal and perinatal outcomes. Midwives may be the first point of care when these conditions arise. This study evaluated the experiences of midwives when providing care to women and people with pregnancies complicated by GDM or HDP.A mixed methods study was completed in Ontario, Canada, using a sequential, explanatory approach. A total of 144 online surveys were completed by midwives, followed by 20 semi-structured interviews that were audio recorded and transcribed verbatim. Survey data were analysed using descriptive statistics. Thematic analysis was used to generate codes from the interview data, which were mapped to the Theoretical Domains Framework (TDF), to elucidate factors that might influence management.Most of the midwives' clinical behaviours relating to GDM or HDP were in keeping with guidelines and regulatory standards set by existing provincial standards. Six theoretical domains from the TDF appeared to influence midwives'care pathway: "Internal influences" included knowledge, skills and beliefs about capabilities; while "external influences" included social/professional role and identity, environmental context, and social influences. Interprofessional collaboration emerged as a significant factor on both the internal and external levels of influence.We identified barriers and facilitators that may improve the experiences of midwives and clients when GDM or HDP newly arises in a pregnancy, necessitating further consultation or management by another health care provider.

Background The ratio of the antiangiogenic factor, soluble fms-like tyrosine kinase 1 (sFlt-1), to the proangiogenic factor, placental growth factor (PlGF), is associated with increased risk of preeclampsia. Here, we describe an analytical evaluation of the Elecsys sFlt-1 and PlGF assays at the first North American site in which they were clinically implemented. Methods The analytical evaluation included short- and long-term imprecision, method comparison, accuracy, linearity, sample stability, limit of quantification verification, and measurement uncertainty. Quality indicators were also evaluated, including turnaround time and repeat test frequency. Results Short-term (13-day) and long-term (12-month) imprecision for sFlt-1 and PlGF were 0.99 and bias 38, >85, and >110) exhibited negative percent agreement and positive percent agreement of 100%, respectively (n = 40). During the first 12 months, 257 orders were placed, repeat test frequency was 17.5%, mean time between repeat orders was 23 days, and 72.0% of results were reported within 2 h from sample receipt when quality control was run continuously. Conclusions We describe analytical performance parameters and quality indicators of the Elecsys sFlt-1 and PlGF assays, which was the first North American clinical laboratory site to implement these assays in support of the institution’s high-risk obstetrical unit.

Antenatal corticosteroids have been shown to decrease neonatal respiratory morbidity in singleton pregnancies when given during the late-preterm period (340/7–366/7 weeks). Whether these findings also apply to late-preterm twins, who account for approximately one-third of infants born at 340/7–356/7 weeks, is currently unclear. The answer to this question depends, in part, on whether the risk of respiratory morbidity among late-preterm twin infants is similar to that observed in late-preterm singletons. We aimed to assess the rate of respiratory morbidity among late-preterm twin infants using a secondary analysis of prospectively collected data from a large international multicenter trial, and to compare that rate with previous studies that used the same definition of respiratory morbidity. This was a secondary analysis of the twin birth study. In the current study, we limited the analysis to women who gave birth during the late preterm period. The primary outcomes were the same primary composite respiratory morbidity variables that were used in the randomized controlled trial of Gyamfi-Bannerman et al., on the administration of betamethasone during the late preterm period in singletons (ALPS trial). The risk of respiratory morbidity among late preterm twins was stratified by gestational week at birth. A total of 1163 women who gave birth to 2324 late preterm twin infants met the inclusion criteria. The rates of respiratory morbidity and severe respiratory morbidity were 16.5% and 8.9%, respectively. The risk of respiratory morbidity was highly dependent on gestational week at birth, being more than fourfold for infants born at 340/7–346/7 weeks (aOR 4.30, 95%–CI 3.01–6.14) and more than twofold for infants born at 350/7–356/7 weeks (aOR 2.12, 95%–CI 1.51–2.98) compared with infants born at 360/7–366/7 weeks. The rate of respiratory morbidity and the theoretical number of women needed to be treated with betamethasone to prevent a single case of respiratory morbidity in the current study were similar to those reported in the APLS trial (16.5% vs. 14.4%, p = 0.103, and NNT 31 vs. 34, respectively). The risk–benefit ratio of betamethasone with regard to neonatal respiratory morbidity in women with twins at risk of late-preterm birth is expected to be similar to that observed in singletons.

A structured approach to hemorrhagic emergencies in obstetrics has gained popularity with the implementation of massive hemorrhage protocols. The trauma literature suggests that routine quality reviews should be in place to improve patient outcomes. The aim of this study was to develop quality indicators and assess compliance by the clinical team.A multidisciplinary team set the institutional quality indicators for the massive hemorrhage protocol review. A retrospective review of all obstetrical massive hemorrhage protocol activation events from September 2010 to January 2015 was performed. All protocol events occurred before the creation of the quality indicators. Data were retrieved from patient records.There were 17 (0.09%) protocol activations for 19 790 deliveries during the study period. All 17 (100%) patients received at least one unit of red blood cells. Overactivation, defined as the transfusion of2 units of red blood cells, occurred in two cases (12%). Common causes of non-compliance were: 24% (4/17) temperature monitoring, 18% (3/17) lactate measurement, 41% (7/17) arterial blood gas sampling, and 18% (3/17) hemoglobin maintenance within the target range of 55-95 g/L. Admission to intensive care and peripartum hysterectomy occurred in 12 and 5 cases (71% and 29%), respectively.Suboptimal compliance was found in multiple areas, which may be attributable to the low frequency of activation of our massive haemorrhage protocol in obstetrics. The quality targets identified in this report can act as a basis for other institutions developing quality indicators to evaluate performance.

Objective: To determine whether preterm birth in a twin pregnancy increases the risk of subsequent preterm birth (PTB) in a singleton pregnancy and to identify predictors for singleton PTB in women with previous twin PTB.Method: A retrospective cohort study of women with prior twin birth followed by a singleton birth in two tertiary referral centres between 2000 and 2016 was conducted. Rate of PTB in subsequent singleton pregnancy was compared between women who experienced previous preterm versus term twin birth. Analysis was further stratified by gestational age at twin and singleton birth, etiology for PTB and chorionicity in the twin pregnancy.Results: A total of 378 women met the inclusion criteria, of whom 252 (66.7%) experienced PTB in the index twin pregnancy. The overall rate of PTB in the subsequent singleton pregnancy was 11.6% (44/378). Women with prior twin PTB had a higher rate of PTB in the subsequent singleton pregnancy compared with women with prior term twin birth (17.5 versus 6.3%, p = .003, or 3.12, 95%-CI 1.42-6.85), mainly due to a higher rate of late singleton preterm birth (13.1 versus 4.0%, p = .005). Findings of higher odds of PTB in the subsequent singleton pregnancy was limited to women who gave birth before 340/7 weeks in the twin pregnancy and was related to the degree of prematurity (prior twin PTB at 300/7-336/7 weeks: OR 3.09, 95%-CI 1.12-8.51; prior twin PTB at

Background The primary aim of this study was to examine weight gain during pregnancy and associated adverse outcomes across different types of antenatal health care providers. Our research question examined whether type of antenatal health care provider (family physician, obstetrician, midwife, or family physician plus obstetrician) was associated with differing rates of excess or inadequate weight gain and associated adverse outcomes including being large for gestational age, being small for gestational age, cesarean delivery and preterm birth. Methods This retrospective cohort study used data from the Better Outcomes Registry & Network Information System, 2014-2016, for singleton hospital births at 20-42 weeks' gestation in Ontario. We calculated descriptive statistics to summarize patient characteristics and outcomes by antenatal health care provider. We calculated crude and adjusted relative risks with 95% confidence intervals (CIs) for the exposure (weight gain during pregnancy) relative to each secondary outcome by health care provider. We calculated population attributable fractions with 95% CIs to assess the proportion of secondary outcomes that could be prevented if inadequate or excess weight gain (according to the 2009 Institute of Medicine guidelines) were removed by health care provider. Results The final cohort consisted of 231 697 pregnancies, of which 26 043 (11.2%), 136 994 (59.1%), 32 262 (13.9%) and 36 298 (15.7%) were managed by a family physician, obstetrician, midwife, and family physician plus obstetrician, respectively. Rates of weight gain below, within or above recommended levels were 31 742 (13.7%), 71 826 (31.0%) and 128 128 (55.3%), respectively, and did not differ across health care provider groups. No difference was observed in rates of secondary outcomes according to weight gain across health care providers. Excess weight gain was associated with a significant risk of being large for gestational age and cesarean delivery, and inadequate weight gain was associated with an increased risk of being small for gestational age and preterm birth. The population attributable fractions indicated a pronounced contribution of excess weight gain to being large for gestational age across all health care provider groups. Interpretation Weight gain during pregnancy and rates of associated secondary outcomes did not differ according to antenatal health care provider. This suggests a need for further research exploring counselling techniques and strategies for all types of antenatal health care providers to use in order to promote optimal weight gain during pregnancy.

In singletons, the pathogenesis of hypertensive disorders of pregnancy (HDP) is attributed to abnormal placentation, characterized by maternal vascular malperfusion (MVM) lesions. Whether MVM plays a similar role in twin pregnancies is unclear. The purpose of the study was to compared placental pathology findings between dichorionic-twin and singleton pregnancies complicated by HDP.Retrospective cohort study of women with dichorionic-twin or singleton pregnancies complicated by HDP who gave birth in a single tertiary center between 2001 and 2015. Placental abnormalities were classified into lesions associated with MVM, fetal vascular malperfusion, placental hemorrhage and chronic villitis. Placental findings and neonatal outcomes were compared between twin and singleton pregnancies.A total of 144 women with twins and 768 women with a singleton pregnancy met the inclusion criteria. Compared with HDP singletons, twins with HDP had higher mean birth weights, were less likely to be small for gestational age and be born at34 and at32 weeks. Twins had lower odds for placental weight below10th percentile (aOR 0.49, 95%CI 0.33-0.71), for MVM pathology (aOR 0.28, 95%CI 0.20-0.39) and for fetal vascular malperfusion pathology (aOR 0.65, 95%CI 0.45-0.93). These finding remained significant in the subpopulation of early onset HDP (34 weeks) and small for gestational newborn.Our findings support the hypothesis that MVM are less relevant to the pathogenesis of HDP in twin pregnancies and suggest that other placental or non-placental factors are responsible for the increased risk of HDP in twin pregnancies.

ObjectivesAntenatal corticosteroids (ACS) decrease neonatal mortality and morbidity among preterm neonates, yet there has been concern regarding their long-term safety. We hypothesised that potential long-term adverse effects of ACS may be observed among infants born during the late preterm period (LPT, 340/7–366/7weeks of gestation), when the benefits of ACS are subtle.DesignPopulation-based, retrospective cohort.SettingOntario, Canada, between 2006 and 2011.PatientsAll live singleton infants born during the LPT period with a minimum 5-year follow-up.InterventionsExposure to ACS prior to 340/7weeks of gestation.Main outcome measuresSuspected neurocognitive disorder, audiometry testing or visual testing.ResultsOverall, 25 668 infants were eligible for analysis, of whom 2689 (10.5%) received ACS. Infants in the ACS group had lower mean birth weight and higher rates of birth weight ConclusionIn children born during the LPT period, exposure to ACS prior to 340/7weeks of gestation is associated with an increased utilisation of the healthcare system related to audiometry and visual testing and suspected neurocognitive disorders by 5 years of age.

Data on the optimal gestational weight gain in twin pregnancies are limited. As a result, the Institute of Medicine currently provides only provisional recommendations on gestational weight gain in this population.This study aimed to identify the optimal range of gestational weight gain in twin pregnancies and to estimate the association between inappropriate gestational weight gain and adverse pregnancy outcomes.This was a retrospective cohort study of all women with twin pregnancies that were followed up in a single, tertiary center between 2000 and 2014. We used 2 approaches to identify the optimal range of gestational weight gain: a statistical approach (the interquartile range of gestational weight gain in low-risk pregnancies with normal outcomes) and an outcome-based approach (by identifying thresholds of gestational weight gain below or above which the rate of adverse outcomes increases). The primary outcome was preterm birth. Associations of gestational weight gain below or above the normal range with the study outcomes were estimated using logistic regression analysis and were expressed as adjusted odds ratio with 95% confidence intervals. These associations were stratified by prepregnancy body mass index group.A total of 1274 women with twin pregnancies met the study criteria: 43 were classified as underweight, 777 were normal weight, 278 were overweight, and 176 were obese. Our estimates of the optimal gestational weight gain range were similar to those recommended by the Institute of Medicine except for the obese category, in which our optimal gestational weight gain range at 37 weeks (9.3-16.3 kg) was lower than in the provisional Institute of Medicine recommendations (11.3-19.1 kg). Nearly half of our cohort experienced inappropriate gestational weight gain: 30% (n=381) gained weight below and 17% (n=216) gained weight above current Institute of Medicine recommendations. In the normal weight group, gestational weight gain below recommendations was associated with an increased risk of preterm birth and birthweight at the10th centile and with a reduction in the risk of hypertensive disorders, whereas gestational weight gain above recommendations was associated with an increased risk of hypertensive disorders and a reduction in the risk of birthweight at the10th centile. Associations were less consistent in the overweight and obese groups.These findings identify gestational weight gain as a potentially modifiable risk factor for preterm birth and other pregnancy complications in twin gestations. Further prospective studies are needed to determine whether interventions aimed at optimizing gestational weight gain can improve the outcomes of these high-risk pregnancies.

IntroductionThe ‘Developmental Origins of Health and Disease’ hypothesis suggests that a healthy trajectory of growth and development in pregnancy and early childhood is necessary for optimal health, development and lifetime well-being. The purpose of this paper is to present the protocol for a randomised controlled trial evaluating a preconception-early childhood telephone-based intervention with tailored e-health resources for women and their partners to optimise growth and development among children in Canada: a Healthy Life Trajectory Initiative (HeLTI Canada). The primary objective of HeLTI Canada is to determine whether a 4-phase ‘preconception to early childhood’ lifecourse intervention can reduce the rate of child overweight and obesity. Secondary objectives include improved child: (1) growth trajectories; (2) cardiometabolic risk factors; (3) health behaviours, including nutrition, physical activity, sedentary behaviour and sleep; and (4) development and school readiness at age 5 years.Method and analysisA randomised controlled multicentre trial will be conducted in two of Canada’s highly populous provinces—Alberta and Ontario—with 786 nulliparous (15%) and 4444 primiparous (85%) women, their partners and, when possible, the first ‘sibling child.’ The intervention is telephone-based collaborative care delivered by experienced public health nurses trained in healthy conversation skills that includes detailed risk assessments, individualised structured management plans, scheduled follow-up calls, and access to a web-based app with individualised, evidence-based resources. An ‘index child’ conceived after randomisation will be followed until age 5 years and assessed for the primary and secondary outcomes. Pregnancy, infancy (age 2 years) and parental outcomes across time will also be assessed.Ethics and disseminationThe study has received approval from Clinical Trials Ontario (CTO 1776). The findings will be published in peer-reviewed journals and disseminated to policymakers at local, national and international agencies. Findings will also be shared with study participants and their communities.Trial registration numberISRCTN13308752; Pre-results.

Background Estimation of fetal weight (EFW) by ultrasound is useful in clinical decision-making. Numerous formulas for EFW have been published but have not been validated in pregnancies complicated by preterm premature rupture of membranes (PPROM). The purpose of this study is to compare the accuracy of EFW formulas in patients with PPROM, and to further evaluate the performance of the most commonly used formula - Hadlock IV. Methods A retrospective cohort study of women with singleton gestations and PPROM, admitted to a single tertiary center between 2005 and 2017 from 220/7–330/7 (n = 565). All women had an EFW within 14 days of delivery by standard biometry (biparietal diameter, head circumference, abdominal circumference and femur length). The accuracy of previously published 21 estimated EFW formulas was assessed by comparing the Pearson correlation with actual birth weight, and calculating the random error, systematic error, proportion of estimates within 10% of birth weight, and Euclidean distance. Results The mean gestational was 26.8 ± 2.4 weeks at admission, and 28.2 ± 2.6 weeks at delivery. Most formulas were strongly correlated with actual birth weight (r > 0.9 for 19/21 formulas). Mean systematic error was − 4.30% and mean random error was 14.5%. The highest performing formula, by the highest proportion of estimates and lowest Euclidean distance was Ott (1986), which uses abdominal and head circumferences, and femur length. However, there were minimal difference with all of the first 10 ranking formulas. The Pearson correlation coefficient for the Hadlock IV formula was strong at r = 0.935 (p p p Conclusions In women with singleton gestation and PPROM, the Ott (1986) formula for EFW was the most accurate, yet all of the top ten ranking formulas performed quite well. The commonly used Hadlock IV performed quite similarly to Ott’s formula, and is acceptable to use in this specific setting.

Background In the Twin Birth Study, women at 320/7–386/7 weeks of gestation, in whom the first twin was in cephalic presentation, were randomized to planned vaginal delivery or cesarean section. The study found no significant differences in neonatal or maternal outcomes in the two planned mode of delivery groups. We aimed to compare neonatal and maternal outcomes of twin gestations without spontaneous onset of labor, who underwent induction of labor or pre-labor cesarean section as the intervention of induction may affect outcomes. Methods In this secondary analysis of the Twin Birth Study we compared those who had an induction of labor with those who had a pre-labor cesarean section. The primary outcome was a composite of fetal or neonatal death or serious neonatal morbidity. Secondary outcome was a composite of maternal morbidity and mortality. Trial Registration: NCT00187369. Results Of the 2804 women included in the Twin Birth Study, a total of 1347 (48%) women required a delivery before a spontaneous onset of labor occurred: 568 (42%) in the planned vaginal delivery arm and 779 (58%) in the planned cesarean arm. Induction of labor was attempted in 409 (30%), and 938 (70%) had a pre-labor cesarean section. The rate of intrapartum cesarean section in the induction of labor group was 41.3%. The rate of the primary outcome was comparable between the pre-labor cesarean section group and induction of labor group (1.65% vs. 1.97%; p = 0.61; OR 0.83; 95% CI 0.43–1.62). The maternal composite outcome was found to be lower with pre-labor cesarean section compared to induction of labor (7.25% vs. 11.25%; p = 0.01; OR 0.61; 95% CI 0.41–0.91). Conclusion In women with twin gestation between 320/7–386/7 weeks of gestation, induction of labor and pre-labor cesarean section have similar neonatal outcomes. Pre-labor cesarean section is associated with favorable maternal outcomes which differs from the overall Twin Birth Study results. These data may be used to better counsel women with twin gestation who are faced with the decision of interventional delivery.

Background The rate of cesarean delivery is continuously increasing with the leading indication being a previous cesarean delivery. For women with 1 previous cesarean delivery, it is generally agreed that the optimal timing of delivery by elective cesarean delivery is during the 39th week of gestation, whereas for women with ≥2 previous cesarean deliveries, the optimal delivery time remains debatable. Objective To assess the maternal and neonatal risks associated with elective delivery at different gestational ages ranging from 37 0/7 to 39 6/7 weeks’ gestation and to compare it with expectant management among women with at least 2 previous cesarean deliveries. Study Design This was a retrospective, population-based cohort study of all women with at least 2 previous cesarean deliveries who delivered after 36 6/7 weeks of gestation in Ontario, Canada, between April 2012 and March 2019. Women with multifetal pregnancies or major fetal anomalies were excluded. For each completed gestational week, outcomes of women who had an elective repeat cesarean delivery at that week solely because of 2 previous cesarean deliveries were compared with the outcomes of those who were managed expectantly and delivered at a later gestational age. The primary outcome was a composite of maternal outcomes including mortality and severe maternal morbidity. Secondary outcomes were adverse neonatal outcomes. Results A total of 26,522 women met the inclusion criteria. The maternal risk was similar for elective delivery at 37 0/7 to 38 6/7 weeks of gestation compared with expectant management. However, elective delivery at 39 0/7 to 39 6/7 weeks’ gestation was associated with a decreased risk for adverse outcomes when compared with expectant management (adjusted risk ratio, 0.51; 95% confidence interval, 0.29–0.91). For the neonate, elective delivery during the 37th week of gestation significantly increased the incidence of the composite adverse outcome than in an ongoing pregnancy (adjusted risk ratio, 1.68; 95% confidence interval, 1.39–2.01), but was comparable for elective delivery at 38 0/7 to 39 6/7 weeks’ gestation and expectant management. The risk for an unplanned cesarean delivery increased from 6.5% before 38 weeks’ gestation to 21.7% before 39 weeks’ gestation and to 32.6% before 40 weeks’ gestation. Conclusion For women with ≥2 cesarean deliveries, elective delivery at 38 0/7 to 38 6/7 weeks’ gestation likely represents the optimal balance between neonatal and maternal risk while decreasing the likelihood of an unplanned cesarean delivery.

The growing prevalence of obesity is a concern for midwives. In Canada, the absence of regulatory standards, varying protocols and consultant preferences shape clinical decision making for the midwife and may lead to inconsistent practice. Our aim was to understand the barriers, enablers, and knowledge gaps that influenced experiences of midwives in Ontario, Canada when providing care to clients impacted by obesity.Mixed methods design using a sequential, explanatory approach. Surveys conducted with midwives were administered using an online platform, followed by semi-structured interviews to understand the perspectives elicited in the survey in greater detail. Interviews were audio recorded and transcribed verbatim. Survey data were analyzed using descriptive statistics, and thematic analysis was used for generating codes, categories and themes from the interview data.144 midwives completed the survey and 20 participated in an interview. The participants described their clinical management when caring for those with obesity which included considerations regarding additional tests/investigations, consultation and transfer of care, and place of birth. Up to 93% of surveyed midwives believed that clients with obesity were appropriate for midwifery-led care however there was less certainty about suitability as BMI increased to higher ranges such as45). The care management was influenced by beliefs and attitudes, knowledge, and system-level factors. Midwives experienced barriers such as inconsistent practices and role confusion, and felt ill equipped to care for pregnancies affected by obesity due to unclear guidelines.Overall, midwives believe clients with obesity are suitable for midwifery-led care due to its individualized, non-judgmental approach to care. Additional training for midwives and other obstetric care providers would be beneficial to help overcome barriers in providing effective care to pregnancies affected by obesity.

Summary Background Although metformin is increasingly being used in women with type 2 diabetes during pregnancy, little data exist on the benefits and harms of metformin use on pregnancy outcomes in these women. We aimed to investigate the effects of the addition of metformin to a standard regimen of insulin on neonatal morbidity and mortality in pregnant women with type 2 diabetes. Methods In this prospective, multicentre, international, randomised, parallel, double-masked, placebo-controlled trial, women with type 2 diabetes during pregnancy were randomly assigned from 25 centres in Canada and four in Australia to receive either metformin 1000 mg twice daily or placebo, added to insulin. Randomisation was done via a web-based computerised randomisation service and stratified by centre and pre-pregnancy BMI ( ClinicalTrials.gov , NCT01353391 . Findings Between May 25, 2011, and Oct 11, 2018, we randomly assigned 502 women, 253 (50%) to metformin and 249 (50%) to placebo. Complete data were available for 233 (92%) participants in the metformin group and 240 (96%) in the placebo group for the primary outcome. We found no significant difference in the primary composite neonatal outcome between the two groups (40% vs 40%; p=0·86; relative risk [RR] 1·02 [0·83 to 1·26]). Compared with women in the placebo group, metformin-treated women achieved better glycaemic control (HbA1c at 34 weeks' gestation 41·0 mmol/mol [SD 8·5] vs 43·2 mmol/mol [–10]; 5·90% vs 6·10%; p=0·015; mean glucose 6·05 [0·93] vs 6·27 [0·90]; difference −0·2 [–0·4 to 0·0]), required less insulin (1·1 units per kg per day vs 1·5 units per kg per day; difference −0·4 [95% CI −0·5 to −0·2]; p Interpretation We found several maternal glycaemic and neonatal adiposity benefits in the metformin group. Along with reduced maternal weight gain and insulin dosage and improved glycaemic control, the lower adiposity and infant size measurements resulted in fewer large infants but a higher proportion of small-for-gestational-age infants. Understanding the implications of these effects on infants will be important to properly advise patients who are contemplating the use of metformin during pregnancy. Funding Canadian Institutes of Health Research, Lunenfeld-Tanenbaum Research Institute, University of Toronto.