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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.

Does a decrease in endometrial thickness (compaction ≥10%) before embryo transfer prognosticate the risk for preterm birth and placenta-mediated pregnancy complications among IVF pregnancies?Retrospective cohort study at a large private fertility practice. Patients with a singleton live birth after a fresh or frozen embryo transfer between 2016 and 2019 were included. The primary outcome was preterm birth (delivery before 37 weeks gestational age). Secondary outcomes included gestational hypertension, pre-eclampsia, intrauterine growth restriction and placental abruption.Of the 252 patients that met the study criteria, 122 (48%) demonstrated endometrial compaction (≥10%) and 130 (52%) did not. Age, body mass index (BMI), parity, history of preterm birth or history of pre-existing maternal conditions between the compaction and no-compaction groups were not significantly different. The overall prevalence of placenta-mediated complications across all participants was 25% (n = 62). The number of preterm births between the compaction and no-compaction groups (13% and 6%, respectively, P = 0.09) as well as the prevalence of placenta-mediated complications (29.5% and 20%, respectively, P = 0.08) were not significantly different. Findings for the primary outcome (preterm birth) persisted even after adjustment for potential confounding variables, including maternal age, parity, BMI, embryo score and type of embryo transfer (fresh versus frozen) (adjusted OR 1.86, 95% CI 0.64 to 5.38).Endometrial compaction (or decrease in endometrial thickness) before embryo transfer is not associated with preterm birth or placenta-mediated pregnancy complications.

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.

In the case of prelabor rupture of membranes at term, the risk for neonatal and maternal infectious morbidity increases progressively with time from prelabor rupture of membranes. Although most studies identified a benefit associated with early induction within the first 24 hours following term prelabor rupture of membranes, there is currently no precise data regarding how early should induction be scheduled.This study aimed to identify the optimal timing of labor induction among women with term prelabor rupture of membranes by comparing the maternal and neonatal outcomes associated with labor induction with those of expectant management at any given 1-hour interval following prelabor rupture of membranes.This was a secondary analysis of data from the TERMPROM trial, an international, multicenter, randomized clinical trial on immediate delivery vs expectant management of women with prelaor rupture of membranes at term (≥37+0/7 weeks' gestation). We considered all participants as a single cohort of women with term prelabor rupture of membranes, irrespective of the original randomized study group allocation. For each given 1-hour time interval within the first 36 hours following prelabor rupture of membranes, we compared the outcomes of subjects for whom labor induction was initiated during this interval with those of subjects managed expectantly at the same time interval. The primary neonatal outcome was a composite of neonatal infection and admission to the neonatal intensive care unit. The primary maternal outcomes included maternal infection (clinical chorioamnionitis or postpartum fever) and cesarean delivery.Of the 4742 subjects who met the study criteria, 2622 underwent labor induction, and 2120 experienced a spontaneous onset of labor. The rates of the neonatal composite outcome, neonatal admission to intensive care unit, and maternal infection increased progressively with time after prelabor rupture of membranes. The risk for these outcomes was lower among women who underwent induction when compared with those managed expectantly within the first 15 to 20 hours after prelabor rupture of membranes without affecting the risk for cesarean delivery. In addition, women who underwent labor induction within the first 30 to 36 hours had a shorter prelabor rupture of membranes to delivery time and a shorter total maternal hospital stay when compared with those managed expectantly at the same time interval. Among women managed expectantly, less than two-thirds (64%; 1365/2120) experienced a spontaneous onset of labor within the first 24 hours following prelabor rupture of membranes.These findings suggest that immediate labor induction seems to be the optimal management strategy to minimize neonatal and maternal morbidity in the setting of prelabor rupture of membranes at term gestations. In cases for which immediate induction is not feasible, labor induction remains the preferred option over expectant management if performed within the first 15 to 20 hours after prelabor rupture of membranes.

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.

To compare pregnancy outcomes in women with pPROM and a cervical cerclage in whom the cerclage was removed within 24 h and those in whom the cerclage was retained in situ. A two-center retrospective cohort study of women with a singleton gestation with pPROM at 48 h (87.2% vs. 65.2%, p = 0.03; aOR 3.9, 95% CI 3.1–4.9) or > 7 days (29.8% vs. 8.7%, p = 0.04; aOR 7.0, 95% CI 2.5–19.6) compared with women in whom cerclage was removed. Furthermore, chorioamnionitis rate was lower in the cerclage retention group compared to cerclage removal group (aOR 0.7, 95% CI 0.5–1.0). There were no differences between the groups in early neonatal sepsis, severe brain injury, or composite neonatal outcome. In women with pPROM and cervical cerclage, retention of cerclage may be associated with a longer latency period, and a lower chorioamnionitis rate, without an associated increase in the risk of neonatal infectious morbidity. Presentation information: The abstract of this study was presented as a poster at the 38th SMFM (Society of Maternal and Fetal Medicine) annual meeting, February 2018, Dallas, Texas, USA.

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.