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No consistent recommendations concerning the preferred tocolytic agents for intrauterine foetal resuscitation are available. We evaluated the effects of acute tocolysis (AT) using ritodrine hydrochloride on foetal heart rate (FHR) patterns and neonatal outcomes. We retrospectively analysed the data of patients undergoing emergency caesarean section because of non-reassuring foetal status indicated by foetal scalp electrodes. Patients were classified into AT (ritodrine hydrochloride approximately 500 µg/min) and control groups with 15 and 12 participants, respectively. FHR patterns, Apgar scores, umbilical arterial analysis, and neonatal admission were compared. All participants had FHR category II; decelerations disappeared in all foetuses in the AT group, with no significant difference in neonatal outcomes. The AT group had a higher baseline FHR and lower short-term FHR variability than the control group, indicating foetal autonomic responses. Further studies are needed to clarify the effects of AT on FHR patterns, neonatal outcomes, and foetal and neonatal autonomic responses.Impact statementWhat is already known on this subject? The usefulness of acute tocolysis using ritodrine hydrochloride has been well-documented in several studies; however, such an application often induces side effects, such as maternal tachycardia, palpitations, and tremors.What the results of this study add? The short-term administration of ritodrine hydrochloride eliminated decelerations, with no significant difference in neonatal outcomes in pregnant women with foetal heart rate category II. Meanwhile, there were higher foetal heart rate and lower short-term foetal heart rate variability in pregnant women administered with ritodrine hydrochloride, indicating foetal autonomic responses.What the implications are of these findings for clinical practice and/or further research? Ritodrine hydrochloride administration, even for short-term, appears to be associated with foetal autonomic responses. Further studies with stratification of patient groups based on the severity and aetiology of non-reassuring foetal status, including pregnant women with foetal category III, would elucidate the risk and benefit of acute tocolysis using ritodrine hydrochloride, based on foetal heart rate patterns, neonatal outcomes, and foetal and neonatal autonomic responses.

Background We report a case of pulmonary edema induced by tocolytic agents that was successfully managed with noninvasive positive-pressure ventilation (NPPV) and resulted in extended gestation. Case presentation A 36-year-old Japanese pregnant woman received tocolytic therapy with ritodrine hydrochloride, magnesium sulfate, nifedipine, and betamethasone from 28 weeks of gestation. She developed respiratory failure. and her chest X-ray showed enlarged pulmonary vascular shadows. At 29 weeks and 1 day of gestation, she was diagnosed with pulmonary edema induced by tocolytic agents. Because respiratory failure worsened 2 days after ritodrine hydrochloride and magnesium sulfate were stopped, NPPV was initiated. Her respiratory status improved and she was weaned off of NPPV after 3 days. She underwent cesarean section because of breech presentation at 30 weeks and 0 days of gestation due to initiation of labor pains. Conclusions NPPV can be safely administered in cases of tocolytic agent-induced pulmonary edema during pregnancy.

Background: Currently, the main goal for the use of tocolytic therapy is to delay the birth so as to allow the use of corticosteroids for accelerating fetal lung maturity and maternal transfer to a tertiary care center and thereby reducing neonatal morbidity and mortality. Aims and Objectives: The aims amd objectives were to compare the safety and efficacy of transdermal nitroglycerine patch with oral nifedipine as a tocolytic agent to arrest preterm labor and prevent preterm birth. Materials and Methods: Based on the selection criteria, 50 patients were selected randomly in Group A and Group B. Group A women were given transdermal nitroglycerin patch, which delivered 10 mg Nitroglycerin (NTG) over 24 h and it was applied to the woman's abdomen followed by another patch of 10 mg after 1 h if contractions persisted. After 24 h, it was replaced by a fresh patch. Group B women were given an oral loading dose of nifedipine 20 mg followed by a similar dose if contractions persisted after 1 h. A maintenance dose of 10 mg thrice daily was given if contractions were suppressed. Patients were monitored from the time of admission to the time of discharge. Results: The mean duration of prolongation of pregnancy in Group B (3.68 ± 1.91 days) was significantly more than Group A (2.78 ± 1.39 days). Headache was seen significantly more in Group A (42%) than group B (6%). Tachycardia, hypotension, and palpitation showed no statistically significant difference between them. There was no statistically significant difference in the birth weight of the babies in both the groups. Conclusion: Nifedipine is a safe and effective drug in prolonging preterm labor and has minimal maternal and neonatal side effects.

Despite safety concerns, β2-sympathomimetics are still widely used as tocolytic agents. β-Blockers in turn are used to treat vasculo-proliferative diseases of the newborn such as retinopathy of prematurity (ROP), which may lead to visual impairment and blindness. The scope of this study was to investigate whether antenatal exposure to the β2-sympathomimetic fenoterol contributes to the development of ROP. For this single-center retrospective case–control study of prospectively collected clinical data, all infants born before 32 weeks of gestation between 2001 and 2012 were included. The association of prenatal exposure to fenoterol and the development of ROP were analyzed by multivariate logistic regression. n = 1134 infants

Objective To evaluate the impact of atosiban as a tocolytic agent in patients treated with the fetoscopic endotracheal occlusion (FETO) procedure due to congenital diaphragmatic hernia (CDH). As premature birth after fetoscopy remains a serious concern, an effort to reduce prematurity is required. Methods A total of 43 patients with severe CDH treated with FETO were enrolled in this study. The study group consisted of 22 patients who received atosiban during the FETO procedure and a control group of 21 patients who did not receive atosiban during the FETO procedure. Demographic data, gestational age (GA) at delivery, cervical length and GA at premature rupture of membranes (PROM) were evaluated. Results The GA at delivery was significantly different between the two groups studied. The median GA at delivery was 32.6 and 34.5 weeks in the no-atosiban vs. atosiban groups, respectively (P = 0.013). The median cervical length was 29.9 and 31.2 mm for the no-atosiban and atosiban groups, respectively, and was not statistically significant (P = 0.28). There were no significant correlations between groups for the occurrence of PROM, GA at the time of PROM, duration of the procedures, parity, maternal body mass index (BMI) or age. In the univariate linear regression model, the only factor independently associated with GA at delivery was the use of atosiban during FETO procedures (β = 0.375; P Conclusion In cases of severe CDH treated with FETO, the use of atosiban as a tocolytic agent during the procedure prolonged pregnancy by 2 weeks. Cervical length, duration of FETO or maternal characteristics were not associated with GA at delivery.

Objective The aim of the study is to obtain insights on the short and long-term safety and effectiveness of isoxsuprine hydrochloride as a tocolytic agent in the management of PTL. Study Design In this prospective, single-center, noncomparative study, patients (with preterm labor at gestational age of 24–37 weeks) were administered intravenous (IV) infusion of 40-mg isoxsuprine hydrochloride until uterine quiescence, followed by intramuscular (IM) injection of isoxsuprine hydrochloride 10 mg/4-hourly for first 24 hours and maintained with retard 40-mg sustained release capsule (two times a day) till the time of delivery or 37 completed weeks of pregnancy. Results All patients (n = 50) achieved successful tocolysis in 24 hours and 48 hours postadministration of isoxsuprine hydrochloride (IV/IM/oral). Mean (±SD) gestation age at the time of delivery was 39.8 ± 2.1 weeks, with latency period of 58.5 ± 18.7 days. Pregnancy outcomes were normal in all the patients and no congenital anomaly/fetal infection was reported. Mean (±SD) fetal birth weight was 2.7 ± 0.3 kg; mean (±SD) Apgar score at 1 and 5 minutes were 7.5 ± 0.6 and 9.2 ± 0.4, respectively. Maternal tachycardia and vomiting (8.0% each) were the commonly reported adverse drug reactions, which were resolved with dose adjustment. Conclusion Isoxsuprine was found to be an effective and well-tolerated tocolytic agent in arresting PTL, in turn resulting in the overall improvement in maternal and perinatal outcomes.

Background:Preterm birth is the major cause of perinatal mortality and morbidity worldwide. Attempts to reduce the burden may be proactive using biochemical or biophysical prediction and preventative measures. If these efforts fail, then the approach may have to be reactive using tocolytics to inhibit spontaneous preterm labour.Objective:We have reviewed the evidence concerning the safety and efficacy of various classes of tocolytic agents.Results:The evidence to support the use of magnesium sulfate or nitric oxide donors as a tocolytic is poor. Compared to placebo or no treatment, there is evidence to support the efficacy of calcium channel blockers (mainly nifedipine), prostaglandin synthetase inhibitors (mainly indomethacin and sulindac), oxytocin receptor antagonists (mainly atosiban) and β2-agonists (mainly ritodrine, terbutaline, salbutamol and fenoterol). Maternal safety concerns have reduced the use of β2-agonists. Fetal safety and gestational age restrictions have largely condemned prostaglandin synthetase inhibitors to second-line therapy. First-line therapy in Europe and other parts of the world outside the USA and Australia is limited to calcium channel blockers and oxytocin receptor antagonists. With respect to efficacy, atosiban and nifedipine are similar, but the robustness of the evidence favours atosiban. With respect to safety, atosiban is clearly the safest tocolytic as there are fetomaternal concerns with nifedipine, particularly in high daily doses.Conclusion:The perfect tocolytic that is uniformly effective and safe does not exist. Cost, licensing and informed consent are considerations involved in the choice. Efforts continue to develop and introduce other or better agents, including novel compounds such as progesterone, PGF2α antagonists and statins.

Despite considerable progress in the field of perinatal care, infectious diseases, especially when caused by gram negative bacteria, remain a major reason for neonatal morbidity and mortality. Notably infants born prematurely and those with very low birth weight are at risk due to their immature and deficient immune system and their prolonged hospitalization which promotes nosocomial infections. In case of impending preterm birth, betamethasone is given to induce lung maturation and tocolytic agents like indomethacin or fenoterol are administered to suppress premature labor. The aim of this study was to analyze the effects of these drugs on the immune system of mothers and neonates. Therefore, mononuclear cells from cord blood and peripheral maternal blood were stimulated with Escherichia coli and incubated with betamethasone, indomethacin and fenoterol. Subsequently the effect of the treatment on cytokine production was determined. Betamethasone alone and in combination with tocolytic agents inhibited the production of pro- and anti-inflammatory cytokines. Not only does betamethasone dampen the immune response by reducing the production of cytokines, it also has a variety of other detrimental short- and long-term effects on the neonate. In conclusion we would recommend using biological markers to determine if premature labor actually leads to preterm birth and subsequently administer betamethasone only to mothers giving birth prematurely.

Background Placenta praevia refers to a placenta located in the lower segment of the uterus. This abnormal location predisposes the placenta to abnormal bleeding with an increased risk of premature labour. The merits of tocolytic drugs (tocolysis) to calm uterine contractions and prolong pregnancy in women with placenta praevia are uncertain. Objectives The primary objective is to determine the effects of tocolysis versus no tocolysis on pregnancy prolongation. Secondary objectives include to determining the effects of tocolysis versus no tocolysis on gestational age at delivery, maternal hospitalisations, recurrent vaginal bleeding, prematurity, admissions into neonatology, and perinatal deaths. Methods We searched MEDLINE, EMBASE, The Cochrane Central Register of Controlled Trials, reference lists of pertinent articles and trial registries for randomised controlled trials comparing tocolysis to no tocolysis or placebo in patients with placenta praevia. Risk of bias and data extraction was done independently by two reviewers. We pooled data using a random-effects model. We used the GRADE system to assess the certainty of evidence for each outcome. Main results There is no significant difference in pregnancy prolongation with the use of tocolysis in cases of placenta praevia (mean difference [MD] 11.51 days; 95% CI, − 1.75, 24.76; 3 trials, 253 participants; low certainty evidence). Tocolysis has no significant effect on gestational age at delivery (MD 0.33 weeks [95% CI − 1.53, 2.19]: 2 trials, 169 participants, moderate certainty evidence), birthweight (MD 0.12 kg [95% CI − 0.26, 0.5 kg]: 2 trials, 169 participants, moderate certainty evidence), risk of premature delivery (risk ratio [RR] 1.04; 95% CI 0.56, 1.94): 2 trials, 169 participants, low certainty evidence), risk of repeat vaginal bleeding (RR 1.05 [95% CI 0.73, 1.51]: 2 trials, 169 participants, moderate certainty evidence). Tocolysis has no significant effect on the risk of perinatal death (risk difference [RD]: 0.00 [95% CI − 0.04, 0.03]: 2 trials, 169 women; low certainty evidence), number of days of maternal hospitalisation (MD 0.60 days [95% CI − 0.79, 1.99]: 1 trial, 109 women; low certainty evidence), risk of fetal admissions into neonatology (RR 1.30 [95% CI 0.80, 2.12]: 1 trial, 109 participants, low certainty evidence) and on the duration of stay in neonatology units (MD 0.70 days [95% CI − 5.26, 6.66]: 1 trial, 109 participants, low certainty evidence). Conclusion In women with symptomatic placenta praevia, there is no significant effect on pregnancy prolongation with the use of tocolysis. Tocolysis has no significant effect on other prenatal, perinatal, neonatal and maternal outcomes among women with symptomatic placenta praevia. Systematic review registration PROSPERO CRD42018091513 Electronic supplementary material The online version of this article (10.1186/s13643-018-0923-2) contains supplementary material, which is available to authorized users.

BACKGROUND Premature labor is an important cause of infant death and long-term disability. This study aimed to explore the safety and effectiveness of combining the tocolytic agents atosiban and ritodrine to extend gestation. MATERIAL AND METHODS The study included 52 patients with late threatened abortion and threatened premature labor between 20⁰⸍⁷ and 33⁶⸍⁷ weeks' gestation who were administrated continuous tocolytic agents for 48 h. Patients were divided into a research group receiving ritodrine combined with atosiban, owing to having no response to ritodrine alone (n=30), and a control group receiving ritodrine alone (n=22). The mean infusion rate and duration of tocolytic administration, gestation extension, pregnancy outcomes, and adverse effects were recorded. Routine blood tests, including C-reactive protein, and cultures for leukorrhea, candida, and mycoplasma were performed before and 1 week after treatment. RESULTS Patients receiving ritodrine with atosiban had a mean gestation extension of 42.53±31.70 days. The extension of gestation of the research group was statistically shorter than that of the control group (P0.05). The fetal loss rate, newborn birth weight, and Apgar score at 1 min were similar between the 2 groups (all, P0.05). The research group had a lower incidence of palpitations than the control group (P0.05). CONCLUSIONS For patients with late threatened abortion or threatened premature labor not controlled with ritodrine alone, ritodrine combined with atosiban extends gestation and improves pregnancy outcomes. For patients with abnormal uterine contractions, routine testing for reproductive tract infection should be performed. When infection is present, anti-infective therapy should be administered.

Tocolytic agents, commonly used for inhibiting preterm labor, pose the risk of uterine atony, leading to postpartum hemorrhage. This study elucidated the effects of different tocolytic agents on postoperative hemorrhage among women in preterm labor undergoing Cesarean delivery (CD). Data from Taiwan National Health Insurance Research Database were analyzed. The risk (adjusted hazard ratio [aHR] and 95% confidence intervals [CI]) of postoperative hemorrhage in CD women with preterm labor diagnosis using tocolytic agents (Tocolysis group) comparing to CD women not using tocolytic agents (Control group) were determined. Impacts of different tocolytic agents in this regard were also investigated. Our data revealed that the incidence (11.7% vs 2.6%, P

Background Currently available tocolytic agents are not effective treatment for preterm labor beyond 48 h. A major reason is the development of maternal side effects which preclude the maintenance of an effective steady-state drug concentration. One strategy that can mitigate these side effects is utilizing synergistic drug combinations to reduce the drug concentrations necessary to elicit a clinical effect. We have previously shown that three anoctamin 1 (ANO1) antagonists mediate potent relaxation of precontracted human uterine smooth muscle (USM). In this study, we aimed to determine whether a combination of sub-relaxatory doses of tocolytic drugs in current clinical use [the L-type voltage-gated calcium channel (VGCC) blocker, nifedipine (NIF); and the β2-adrenergic (β2AR) agonist, terbutaline (TRB)] will potentiate USM relaxation with two ANO1 antagonists [benzbromarone (BB) and MONNA (MN)]. Objective This study sought to examine the synergistic potency and mechanistic basis of two ANO1 antagonists with currently available tocolytic drugs. Functional endpoints assessed included relaxation of pre-contracting pregnant human USM tissue, inhibition of intracellular calcium release, and reduction of spontaneous transient inward current (STIC) recordings in human uterine smooth muscle cells. Methods Human myometrial strips and primary human USM cells were used in organ bath and calcium flux experiments with different combinations of sub-threshold doses of ANO1 antagonists and terbutaline or nifedipine to determine if ANO1 antagonists potentiate tocolytic drugs. Results The combination of sub-threshold doses of two ANO1 antagonists and current tocolytic drugs demonstrate a significant degree of synergy to relax human pregnant USM compared to the effects achieved when these drugs are administered individually. Conclusion A combination of sub-threshold doses of VGCC blocker and β2AR agonist with ANO1 antagonists potentiates relaxation of oxytocin-induced contractility and calcium flux in human USM ex vivo. Our findings may serve as a foundation for novel tocolytic drug combinations.

AIMS Magnesium sulfate has neuroprotective effects in preterm infants. Whether other antepartum treatments interfere with the neuroprotective actions is not well known. This study aims to explore the impacts of antenatal administration of Magnesium sulfate or beta-2 adrenergic agonists as tocolytic agents on the developing brain in premature infants. METHODS This is a retrospective cohort study in four tertiary perinatal centers in Japan. We collected data of pregnant women and infants born between 28 and 36 weeks for tocolytic agents, gestational age, sex, antenatal corticosteroid, fetal growth restriction, pathological chorioamnionitis, low umbilical arterial pH values (

Background The herbal medicine Bryophyllum pinnatum has been used as a tocolytic agent in anthroposophic medicine and, recently, in conventional settings alone or as an add-on medication with tocolytic agents such as atosiban or nifedipine. We wanted to compare the inhibitory effect of atosiban and nifedipine on human myometrial contractility in vitro in the absence and in the presence of B. pinnatum press juice (BPJ). Methods Myometrium biopsies were collected during elective Caesarean sections. Myometrial strips were placed under tension into an organ bath and allowed to contract spontaneously. Test substances alone and at concentrations known to moderately affect contractility in this setup, or in combination, were added to the organ bath, and contractility was recorded throughout the experiments. Changes in the strength (measured as area under the curve (AUC) and amplitude) and frequency of contractions after the addition of all test substances were determined. Cell viability assays were performed with the human myometrium hTERT-C3 and PHM1–41 cell lines. Results BPJ (2.5 μg/mL), atosiban (0.27 μg/mL), and nifedipine (3 ng/mL), moderately reduced the strength of spontaneous myometrium contractions. When BPJ was added together with atosiban or nifedipine, inhibition of contraction strength was significantly higher than with the tocolytics alone (p = 0.03 and p Conclusions BPJ enhances the inhibitory effect of atosiban and nifedipine on the strength of myometrial contractions, without affecting myometrium tissue or cell viability. The combination treatment of BPJ with atosiban or nifedipine has therapeutic potential.

Globally, preterm birth rates are rising and have a significant impact on neonatal morbidity and mortality. Preterm birth remains difficult to prevent and a number of strategies for preterm birth prevention (progesterone, cervical pessaries, cervical cerclage, tocolytics, and antibiotics) have been identified. While some of these show more promise, there is a paucity of evidence regarding the long-term effects of these strategies on childhood outcomes. Strategies used to improve the health of babies if born preterm, such as antenatal magnesium sulfate for fetal neuroprotection and antenatal corticosteroids for fetal lung maturation, show evidence of short-term benefit but lack large-scale follow-up data of long-term childhood outcomes. Future research on preterm birth interventions should include long-term follow-up of the children, ideally with similar outcome measures to allow for future meta-analyses.

We conducted a questionnaire survey on the current obstetric management of preterm labor (PL) and preterm premature rupture of the membranes (pPROM). The questionnaire covered approximately a third of all preterm deliveries and nearly half of the preterm deliveries before 32 gestational weeks. The diagnostic criterion for PL was either painful uterine contractions or cervical dilatation. Tocolytic agents were primarily used as long-term maintenance therapy. Intrauterine infection was clinically diagnosed at most responding institutions. Amniocentesis was performed for PL or pPROM at only a small number (10%) of institutions. Prenatal steroids were administered for PL or pPROM, if indicated, at approximately 40-60% of responding institutions. Prophylactic antibiotics to maintain pregnancy were administered for pPROM at approximately 90% and for PL at approximately 20% of institutions. Maintenance therapy with a tocolytic agent was used for pPROM at approximately 90% of institutions.

Objective The aim of this systematic review and meta-analysis was to quantify the efficacy of cervical cerclage in preventing preterm birth (PTB) in asymptomatic singleton pregnancies with a short mid-trimester cervical length (CL) on transvaginal sonography (TVS) and without prior spontaneous PTB. Methods Electronic databases were searched from inception of each database until February 2017. No language restrictions were applied. All randomized controlled trials (RCTs) of asymptomatic singleton pregnancies without prior spontaneous PTB, found to have short CL

Periviable birth contributes disproportionately to perinatal morbidity and mortality. By analyzing the most relevant outcomes after a preterm birth some information can be provided on the potential benefit of interventions. This article discusses surgical and medical interventions that may offer neonatal benefit including cerclage, amniocentesis, progesterone, antenatal corticosteroids, magnesium sulfate for neuroprotection, and tocolysis. Cervical cerclage has the greatest promise at reducing morbidity and mortality related to periviable birth even though it may not reduce the overall preterm birth rate. The use of antenatal corticosteroids, magnesium sulfate, progesterone, and tocolytics may also improve outcome. Studies specifically evaluating these interventions are needed.

As a tocolytic agent, ritodrine has been used in European and Asian countries but has lost popularity due to safety concerns. This study aimed to investigate the relationship between adverse drug events caused by ritodrine and the CACNA1C polymorphisms in preterm labor patients. Data were collected from medical records including maternal age, gestational age, body mass index, dilation score, effacement score, modified Bishop score, maximum infusion rate, and adverse drug events. Five single-nucleotide polymorphisms of the CACNA1C gene (rs10774053, rs215994, rs215976, rs2239128, and rs2041135) were analyzed. One hundred eighty-six patients were included, 33 of whom had adverse drug events. A allele carriers of rs10774053 showed about 0.293-fold lower adverse drug events than GG genotype carriers (p = 0.012, absolute risk reduction = 16.5%) after adjusting for other confounding variables; the number needed to genotype for preventing one patient with GG genotype from suffering higher incidence of adverse drug events was calculated to be 14.6. Increase in maximum infusion rate of 1 mL/h was associated with a 1.03-fold (95% CI 1.01~1.06, p = 0.005) increased risk of adverse drug events. None of the patients with a CC genotype of rs215994 had adverse drug events, whereas 22.1% of the T allele carriers had adverse drug events. This study showed that CACNA1C gene polymorphisms could alter the probability of adverse drug event risk when ritodrine is used in preterm labor.

One of the most established roles of oxytocin (OT) is in inducing uterine contractions and labor. Apart from inducing contractions, our recent studies showed that OT can also activate proinflammatory pathways in both human myometrial and amnion cells, which suggests that the proinflammatory role of OT should be taken into account when developing tocolytics targeting the OT/oxytocin receptor (OTR) system. The OTR antagonist, atosiban, is currently used therapeutically for the treatment of preterm labor. We previously showed that atosiban fails to inhibit the proinflammatory effects of OT in human amnion; atosiban alone activates nuclear factor-κB (NF-κB) and mitogen activated protein kinases, thus upregulating downstream prolabor genes. In contrast with our findings with atosiban, the presence of the orally active OTR antagonist, nolasiban, reduced the effect of OT on NF-κB and p38 kinase activation in both myometrial and amnion cells. Consistent with the activation of these inflammatory mediators, OT led to increases in the expression of cyclooxygenase-2 and phosphorylated cytosolic phospholipase A2, which was reflected in prostaglandin E2 synthesis. Inhibition of NF-κB activation by nolasiban also translated to suppression of downstream prolabor gene expression, such as cyclooxygenase-2, C-C motif chemokine ligand 2, interleukin-6, and interleukin-8. We also demonstrated that nolasiban treatment alone has no significant stimulatory effect on both the myometrium and amnion. In conclusion, our findings indicate that nolasiban possesses promising potential as a novel tocolytic agent for both acute and maintenance therapy, as it inhibits both myometrial contractions and the proinflammatory effects of OT without the biased agonist effects.

Congenital heart disease (CHD) is the most common birth defect. It is due to dysfunction of the heart and great vessels during embryo development stage, or the channel was not closed after birth. This study focuses on investigating the influence of virus infection and medicine history during pregnancy on the incidence rate of CHD of fetus. We conducted a retrospective birth cohort study of infant born in the maternal and child health hospital of Fanyu district in Guangzhou. Five thousand three hundred eighty one cases with complete medical records, including mothers, fathers, and infants, were enrolled. The exposure history of mothers to virus and medicine from 6 months before pregnancy to prenatal examination was investigated, including mflu, mumps, measles, rubella, chickenpox, and hepatitis and antibiotics, tocolytic agent, anticonvulsants, antipyretic and analgesic, antitumor drug, folic acid supplement, and contraceptive. The relationship between virus infection and medicine history during pregnancy and CHD was analyzed. There was statistical difference between a normal group and a defected group in influenza infection and tocolytic agent and contraceptive pill. The exposure history to influenza and medicines, such as tocolytic agent and contraceptive pill, during pregnancy influenced the incidence rate of CHD of fetus.

Tocolytic agents are used to inhibit uterine contraction in preterm. The authors undertook this study to determine whether using of tocolytic agents before delivery is associated with increase postpartum hemorrhage in preterm delivered women.296 singleton pregnancies delivered preterm from 24 + 1 to 37 + 0 weeks gestation were retrospectively reviewed. Hemoglobin (HB) and hematocrit (HCT) levels were checked before and after delivery to access postpartum blood loss. Multivariate logistic regression analysis was performed to determine whether delivery within the half-lives of tocolytic agents was associated with decreased HB and HCT levels.After adjusting for maternal age, parity, gestational age at delivery, birth weight, delivery method, and induction of labor, postpartum HB and HCT levels of those delivered within half-lives of tocolytic agents were found to be significantly diminished (HB: OR 3.306, 1.308-8.356 95% CI, p = 0.011; HCT: OR 2.692, 1.077-6.726 95% CI, p = 0.034). In addition, blood transfusion rates were elevated for deliveries made within the half-lives of tocolytic agents, (p = 0.006).Delivery within half-lives of tocolytic agents was found to be associated with low HB and HCT levels after delivery and higher blood transfusion rates in preterm delivered women.

Introduction: Tocolytics may cause changes in fetal heart rate (HR) pattern, while fetal heart rate variability (HRV) is an important marker of fetal well-being. We aim to systematically review the literature on how tocolytic drugs affect fetal HRV.Materials and methods: We searched CENTRAL, PubMed and EMBASE up to June 2016. Studies published in English, using computerized or visual analysis to describe the effect of tocolytics on HRV in human fetuses were included. Studies describing tocolytics during labor, external cephalic version, pre-eclampsia and infection were excluded. Eventually, we included six studies, describing 169 pregnant women.Results: Nifedipine, atosiban and indomethacin administration show no clinically important effect on fetal HRV. Following administration of magnesium sulfate decreased variability and cases of bradycardia are described. Fenoterol administration results in a slight increase in fetal HR with no changes in variability. After ritodrine administration increased fetal HR and decreased variability is seen. The effect of co-administration of corticosteroids should be taken into account.Conclusion: In order to prevent iatrogenic preterm labor, the effects of tocolytic drugs on fetal HRV should be taken into account when monitoring these fetuses.Keywords: Tocolytic therapy, calcium channel blocker, oxytocin receptor antagonist, prostaglandin antagonist, beta-adrenergic agonist, fetal heart rate variability

Maintenance tocolysis, mostly defined as the continuation of tocolytic treatment beyond 48 h, remains a matter of debate. There is no sufficient evidence from randomized controlled trials, that maintenance tocolysis is able to prolong pregnancy significantly and to reduce severe neonatal morbidity and mortality. Hence, it is not recommended in current guidelines. On the contrary, maintenance tocolysis is commonly used in clinical practice and subject of current clinical-scientific investigations. None of the conventional tocolytics (beta-sympathomimetics, calcium-channel blockers, magnesium, cyclooxygenase inhibitors, and oxytocin receptor antagonists) have proven to be appropriate for maintenance treatment. Progesterone and 17-α-hydroxyprogesterone caproate have shown promising results in low-quality randomized trials, but not in high-quality studies. Basically, the value of studies regarding maintenance tocolysis is limited by a considerable heterogeneity, its mostly low quality, significant differences in methodology as well as the inadequate statistical power due to the small number of women studied. So far, maintenance tocolysis is a case-by-case decision outweighing the benefits and harms of tocolytic treatment.

Preterm birth can be medically-indicated or spontaneous. Almost half of spontaneous preterm deliveries are preceded by preterm labor. Preterm labor is a clinical diagnosis characterized by regular uterine contractions (painful or painless) with concomitant cervical change. This article discusses the prevention and treatment of spontaneous preterm labor utilizing progesterone and tocolytic agents and provides management recommendations in patients with and without a history of prior spontaneous preterm birth.

Objectives: To summarize current evidence on the use of tocolytic medications perioperatively for open prenatal repair of fetal myelomeningocele including tocolytic agent options, regimens, efficiency, and potential risks. Methods: A search of Medline, Embase, and SCOPUS databases was conducted from inception to March 2017. Studies that described their tocolytic protocol, gestational age at delivery, perinatal outcomes were included. Studies that did not exclusively assessed fetal myelomeningocele or did not adequately endorse obstetric and neonatal outcomes were excluded. Neither sample size nor language was a basis for exclusion. Results: Out of 570 studies retrieved on initial search, 462 were excluded for irrelevance. Of the 61 remaining titles, 17 were animal studies, 17 were reviews, 12 studied a spectrum of anomalies, three specified fetoscopy, four did not report neonatal outcomes, and one article was retracted. Two studies were added to the pool when the literature search was updated. Nine articles were eventually included; three case reports, six cohort studies with a total of 205 cases. Fetuses were managed at gestational ages between 19 and 30 weeks. Although tocolytic regimens were variable, indomethacin was commonly utilized as a preoperative tocolytic. Magnesium sulfate was usually initiated intraoperatively and was resumed postoperatively for a variable duration (18–48 hours) with or without subcutaneous terbutaline. Gestational age at delivery ranged from 30–37 weeks with an average of 33–35 weeks. Pulmonary edema was reported in two studies to be 2.2–5.5%. Perinatal outcomes were overall favorable. Conclusion: Preoperative indomethacin and postoperative course of magnesium sulfate seem to be a favorable tocolytic option in women with open prenatal myelomeningocele repair. Risks are generally minimal. However, adequate information on the duration of postoperative tocolysis seems to be inadequate.

Background Laparoscopic surgery is well accepted as a safe technique when performed on a third trimester pregnant woman. Objective The aim is to describe the anaesthetic management of a group of patients undergoing this type of surgery. Material and methods An analysis was made of records of 6 patients in their third trimester of pregnancy and who underwent urgent laparoscopic surgery from 2011 to 2013. Clinical Cases The study included 6 patients, with a diagnosis of acute cholecystitis in 4 of them. The other 2 patients had acute appendicitis, both of who presented threatened preterm labour. Conclusion The most frequent indications for laparoscopic surgery during the last trimester of birth were found to be acute cholecystitis and acute appendicitis. Acute appendicitis is related to an elevated risk of presenting threatened preterm labour.

Objective To undertake a survey of the world's clinical trial registries to provide current data on the number, nature, funding source and geographical distribution of pregnancy drug trials (PDT). Design and setting Comprehensive analysis of WHO-certified clinical trial registries. Methods Sixteen registries containing 301 538 trials (168 826 active in 2013–2014) were analysed to identify the numbers, location, funding sources, and areas of interest/development of PDTs. Results The percentage of PDTs varied from 0 to 7.4% across registries. Overall, just 0.32% (534) of all active registered studies were PDTs. The US registry (Clinicaltrials.gov) was the largest database, but contributed just 14% of all active PDTs. The majority of PDTs focused on anaesthesia/analgesia, preterm birth/tocolysis, labour induction, endocrine and hypertensive disorders. Less than 6% of active PDTs focused on maternal or fetal health as a specific primary outcome, and only 4.4% included a preplanned pharmacokinetic analysis of the trial medications. A third of all active PDTs involved repurposing of existing medicines for applications in pregnancy, whereas only three new investigational drugs had been developed for a pregnancy indication. Seven percent of all active PDTs identified were pharmaceutical industry-funded. Inter-disease comparisons identified a ~50-fold disparity in trial activity between pregnancy and other comparable areas. Conclusions This study demonstrates unequivocally the marked under-representation of medication development, evaluation and safety trials in pregnancy. The likelihood that the current pharmaceutical landscape in pregnancy will improve in the foreseeable future is slim. Advocacy and increased awareness of the issue is necessary to achieve positive change. Tweetable abstract Pregnant women are significantly under-represented in global clinical drug trials.

Introduction: Preterm birth is the major cause of neonatal mortality and morbidity worldwide and a huge cost burden on healthcare. Between 22 and 26 completed weeks of gestation, for every day that delivery is delayed, survival increases by 3%. Areas covered: Following a systematic review of the literature, we have provided an overview of the use of tocolytics for the prevention of preterm birth and have examined the fetal and maternal adverse effects of the various tocolytic agents currently in use. Expert opinion: No tocolytic currently in use was developed specifically to treat preterm labour so most have multi-organ side effects. β 2-agonists are relatively safe for the fetus but have rare and potentially serious maternal adverse effects. In contrast, prostaglandin synthetase inhibitors have potentially serious side effects for the fetus and neonate but have mild maternal gastrointestinal side effects. In Europe, the choice of first line therapy is either atosiban or nifedipine. The evidence base for atosiban is much more robust than for nifedipine. While their efficacy is similar, atosiban has placebo level side effects and is safer than nifedipine but is much more expensive.

Preterm labour is defined as the onset of labour between weeks 23 and before 37 of gestation. The purpose of this study was to compare the cytokine profile in the blood serum of patients experiencing threatened premature labour, along with the time of delivery and the foetus body mass at birth.The study included 89 women hospitalised at the Obstetrics and Gynaecology Clinical Hospital in the period 2011-2013. Group 1 comprised 31 patients diagnosed with threatened preterm labour, prior to tocolytic treatment. Group 2 comprised 32 patients with tocolytic treatment. Group 3 constituted the control group.Groups 1, 2 and 3 differed considerably in terms of the week of delivery of pregnancy (p = 0.006). Analogous results were obtained by analysing the body mass at birth, where a statistically significant difference in body mass at birth was found between Groups 1, 2 and 3 (p 0.001). Our analysis focussed on the cytokine profile of the women included in the study, but no considerable changes in cytokine concentration were observed.No statistically significant differences were found in the cytokine profile among those patients in normally progressing pregnancy or in threatened preterm labour. No suitability of progesterone treatment in threatened preterm labour was observed.

Emergency cerclage refers to a cerclage placed during the second trimester in a woman noted to have painless cervical dilation. Although randomized-controlled trials are limited, observational studies suggest an improvement in neonatal outcomes in selected patients undergoing an emergency cerclage. Labor and chorioamniontis are contraindications for cerclage placement. Advanced dilation (>3 to 4 cm) and a later gestational age (22 to 24 wk) are associated with poorer outcomes. This chapter reviews the indications, outcomes and perioperative management strategies for cerclage placement in this setting.

Obstetric anesthesiologists are supposed to understand the uterotonics and tocolytics used in the perinatal period to provide a better clinical practice. This review describes current consensus of uterotonics and tocolytics used in the perinatal period that an obstetric anesthesiologist should know.Rational use of uterotonics for cesarean section has been well studied in the past decades. Oxytocin remained as a first line uterotonics for cesarean section. For continuous infusion, it is reported that ED90 is higher for laboring parturients than for nonlaboring parturients (6.2 vs. 44.2 IU/h) implying that protocol for oxytocin infusion should be different between laboring patients with prior exposure to oxytocin and nonlaboring patients. For bolus administration, 'rule of three' has been proposed and its efficacy has been reported. When oxytocin fails to achieve sufficient uterine contraction, second-line agents must be administered, and it has been reported that methylergonovine is a superior second-line uterotonic to carboprost. On the other hand, the role of tocolytic agents in obstetric anesthesia has not been well studied.Anesthesiologists involved in obstetric anesthesia should be able to determine the appropriate uterotonic for cesarean section and know the indication of tocolytics in perinatal period.

Objective: No treatment is recommended for routine maintenance tocolysis after an arrested preterm birth. Our present study aimed to evaluate the effect of progesterone and nifedipine as maintenance tocolysis therapy after an arrested preterm birth. Materials and Methods: For relevant studies, we systematically searched the literature in databases of PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library. Only randomized controlled trials were included. Results: Nine trials were included in our review. Nifedipine and progesterone were used for maintenance tocolysis. Compared to placebo treatment or no treatment, maintenance tocolysis with progesterone could significantly prolong the delivery gestational weeks [standard mean difference (SMD) 1.64; 95% confidence interval (CI), 1.21, 2.07; p

Objective: To evaluate autonomic modulation of heart rate in pregnant women treated with oxytocin to induce labor and with atosiban (an oxytocin antagonist) to arrest preterm labor.Methods: A prospective study with two cohorts: 14 pregnant women treated with atosiban for premature uterine contractions, and 28 women undergoing induction of labor with oxytocin. Computerized analyses of the electrocardiogram were performed with spectral and nonlinear dynamic analyses.Results: Atosiban did not alter any of the variables associated with heart rate variability, whereas oxytocin showed a dose-dependent decrease in heart rate (p

Preterm delivery presents the main cause of neonatal morbidity and mortality worldwide. The rate of preterm delivery is 12% to 13% in the United States, of which 29% concerns preterm deliveries before 34 weeks of gestation. Basic parameter of prevention strategy is implementation of tocolytic therapy in cases of threatened preterm labor. Several therapeutic approaches have been proposed, among which betamimetic agonists, calcium channel blockers, magnesium sulfate, oxytocin receptor blockers, nitrates, and prostaglandin inhibitors, whereas new alternatives such as usage of thiocolchicoside have also been reported. This article is one among few that aims to review the comparative effectiveness of various tocolytic agents regarding prevention of preterm delivery, impact on perinatal morbidity and mortality, neonatal health status, and maternal complications. Main conclusions of recent randomized control trials and meta-analyses are summarized to assess about which agents consensus already exists on their effectiveness, which agents should be further studied to achieve conclusions, as well as those that are rather unlikely to have significant tocolytic impact or any other benefit on neonatal outcome.

Patients with pregnancies complicated with premature uterine contractions (PMC), but delivered at term are considered as false preterm labor (PTL), and represent a common obstetric complication. We aimed to assess obstetric and neonatal outcomes of pregnancies complicated with PMC, but delivered at term, as compared to term normal pregnancies.Obstetric, maternal and neonatal outcomes of singleton pregnancies complicated with PMC between 24-33(6)/7 weeks (PMC group), necessitating hospitalization and treatment with tocolytics and/or steroids, during 2009-2014, were reviewed. The study group included only cases who eventually delivered ≥37 weeks, which were compared to a control group of subsequent term singleton deliveries who had not experienced PMC during pregnancy. Neonatal adverse composite outcome included: phototherapy, RDS, sepsis, blood transfusion, cerebral injury, NICU admission.The PMC group (n=497) was characterized by higher rates of nulliparity (p=0.002), infertility treatments (p=0.02), and polyhydramnios (p0.001), as compared to controls (n=497). Labor was characterized by higher rates of instrumental deliveries (p=0.03), non-reassuring fetal heart rate tracings (p0.001) prolonged third stage of labor (p=0.04), and increased rate of post-partum maternal anemia (Hb8g/dL) p=0.004, in the PMC group as compared to controls. Neonates in the PMC groups had lower birth weights compared to controls, 3149g±429 vs. 3318g±1.1, p0.001, respectively. By logistic regression analysis, PMC during pregnancy was independently associated with neonatal birth-weight3rd percentile (adjusted OR 4.6, 95% CI 1.5-13.7).Pregnancies complicated with PMC, even-though delivered at term, entail adverse obstetric and neonatal outcomes, and may warrant continued high risk follow up.

The standard treatment for retained placenta is manual removal whatever its subtype (adherens, trapped or partial accreta). Although medical treatment should reduce the risk of anesthetic and surgical complications, they have not been found to be effective. This may be due to the contrasting uterotonic needs of the different underlying pathologies. In placenta adherens, oxytocics have been used to contract the retro‐placental myometrium. However, if injected locally through the umbilical vein, they bypass the myometrium and perfuse directly into the venous system. Intravenous injection is an alternative but exacerbates a trapped placenta. Conversely, for trapped placentas, a relaxant could help by resolving cervical constriction, but would worsen the situation for placenta adherens. This confusion over medical treatment will continue unless we can find a way to diagnose the underlying pathology. This will allow us to stop treating the retained placenta as a single entity and to deliver targeted treatments.

Tocolytics have been used for over 60 years for women with preterm labor, which ultimately can lead to preterm birth (PTB). Diagnosing preterm labor is challenging, but use of objective tests such as transvaginal ultrasound of cervical length assists in the identification of women at the highest risk for PTB. Once preterm labor has been diagnosed, clinicians can choose from a variety of drug classes (cyclooxygenase inhibitors, calcium channel blockers, and betamimetics) to achieve the primary goal of delaying delivery by 48 hours, thereby allowing time for administration of corticosteroids for fetal lung maturity, and if appropriate, starting magnesium sulfate for fetal neuroprotection. Cyclooxygenase inhibitors are the only class of tocolytics proven to decrease PTB 37 weeks. Knowledge of the safety and effectiveness of these medications is paramount. Several additional agents (e.g., oxytocin receptor antagonists) have significant promise, but further studies are required before these medications can be approved for tocolysis in the United States. As we look into the future of tocolysis, we anticipate that deeper understanding of the complex physiology of preterm labor will allow us to uniquely target different etiologies that lead to the final path resulting in spontaneous preterm delivery.

Item does not contain fulltext BACKGROUND: In women with threatened preterm birth, delay of delivery by 48 h allows antenatal corticosteroids to improve neonatal outcomes. For this reason, tocolytics are often administered for 48 h; however, there is no consensus about which drug results in the best maternal and neonatal outcomes. In the APOSTEL III trial we aimed to compare the effectiveness and safety of the calcium-channel blocker nifedipine and the oxytocin inhibitor atosiban in women with threatened preterm birth. METHODS: We did this multicentre, randomised controlled trial in ten tertiary and nine teaching hospitals in the Netherlands and Belgium. Women with threatened preterm birth (gestational age 25-34 weeks) were randomly assigned (1:1) to either oral nifedipine or intravenous atosiban for 48 h. An independent data manager used a web-based computerised programme to randomly assign women in permuted block sizes of four, with groups stratified by centre. Clinicians, outcome assessors, and women were not masked to treatment group. The primary outcome was a composite of adverse perinatal outcomes, which included perinatal mortality, bronchopulmonary dysplasia, sepsis, intraventricular haemorrhage, periventricular leukomalacia, and necrotising enterocolitis. Analysis was done in all women and babies with follow-up data. The study is registered at the Dutch Clinical Trial Registry, number NTR2947. FINDINGS: Between July 6, 2011, and July 7, 2014, we randomly assigned 254 women to nifedipine and 256 to atosiban. Primary outcome data were available for 248 women and 297 babies in the nifedipine group and 255 women and 294 babies in the atosiban group. The primary outcome occurred in 42 babies (14%) in the nifedipine group and in 45 (15%) in the atosiban group (relative risk [RR] 0.91, 95% CI 0.61-1.37). 16 (5%) babies died in the nifedipine group and seven (2%) died in the atosiban group (RR 2.20, 95% CI 0.91-5.33); all deaths were deemed unlikely to be related to the study drug. Maternal adverse events did not differ between groups. INTERPRETATION: In women with threatened preterm birth, 48 h of tocolysis with nifedipine or atosiban results in similar perinatal outcomes. Future clinical research should focus on large placebo-controlled trials, powered for perinatal outcomes. FUNDING: ZonMw (the Netherlands Organisation for Health Research and Development).

Objective To analyze the amount of surfactant protein (SP)-B and lecithin/sphingomyelin (L/S) ratio in response to betamethasone (BMS) alone as compared with magnesium sulfate (Mg 2+ ), indomethacin (Indo), and nifedipine (Nif) with or without BMS. Study design NCI-H441 human lung cells were grown and distributed into eight plates. BMS and tocolytics were added and the final plates were: control, BMS only, and each tocolytic ± BMS. Cells were stained with SP-B antibodies and relative fluorescence was measured. Lipids were also extracted, identified, and examined for relative densities. The L/S ratio was calculated. Results Nine independent measurements were obtained for each plate. The protein analysis revealed that among all eight plates, SP-B levels were highest among BMS only. There was a nonsignificant decrease in SP-B in each of the combinations of tocolytics + BMS as compared with BMS only. Compared with BMS only, L/S ratio was decreased in Mg 2+ + BMS ( p = 0.041), Indo + BMS ( p = 0.042), and Nif + BMS ( p = 0.025). Conclusion In our in vitro human lung cell model, SP-B and L/S ratio increased in response to BMS administration alone. The addition of tocolytics to BMS resulted in no increase in L/S ratio and no changes seen in SP-B production compared with BMS alone.

Background : Magnesium sulphate (MgSO 4 ) has been recommended for fetal neuroprotection to prevent cerebral palsy, with national societies adopting new guidelines for its use. A knowledge translation project to implement Canadian guidelines is ongoing. Discussion about MgSO 4 for fetal neuroprotection could not occur distinct from MgSO 4 for eclampsia prophylaxis and treatment. Thus, in order to explore standardization of MgSO 4 use in Canada, we sought to compare local protocols for eclampsia and fetal neuroprotection across tertiary perinatal centres. Methods : Twenty-five Canadian tertiary perinatal centres were asked to submit their protocols for use of MgSO 4 for eclampsia prophylaxis/treatment and fetal neuroprotection. Information abstracted included date of protocol, definitions of indications for treatment, details of MgSO 4 administration, maternal and fetal monitoring, antidote for toxicity, and abnormal signs requiring physician attention. Descriptive analyses were used to compare site protocols with known definitions of preeclampsia. Data from the Canadian Perinatal Network (CPN) were used to verify what was done in clinical practice. Results : Twenty-two of the 25 centres submitted protocols for eclampsia prevention/treatment. Eleven of these provided a definition of preeclampsia that warranted treatment; five of the 22 advised treatment of severe preeclampsia only. Criteria for treatment and monitoring procedures varied across centres. Sixteen of the 22 sites with protocols had data from the CPN. Of 635 women with pre-eclampsia, 422 (66 5%) received MgSO 4 Twenty of 25 centres provided protocols for fetal neuroprotection. Definitions of indications were consistent across sites, except for gestational age cut-off. Conclusion : This study suggests that local protocols are often inconsistent with published evidence. While this may be related to local institutional practices, relevant processes must be put in place to maximize uniformity of practice and improve patient care.

Key Points Question Is tocolysis associated with lower rates of death and intraventricular hemorrhage in preterm infants owing to an effect on the fetal blood-brain barrier? Findings In this cohort study of 1127 mothers who experienced preterm labor and delivered at gestational weeks 24 through 31, the estimated prevalence of death and/or grades III to IV intraventricular hemorrhage was significantly lower in preterm infants with vs without tocolytic exposure (25.3% vs 32.5%). Differences between atosiban and nifedipine exposure for death and/or intraventricular hemorrhage (44.9% vs 51.2%) and for intraventricular hemorrhage (39.1% vs 45.3%) were not significant. Meaning Results for tocolytics are reassuring regarding death and/or intraventricular hemorrhage in preterm infants, but other studies appear to be necessary to compare the effects of atosiban vs nifedipine., This population-based cohort study assesses the risks associated with tocolysis as measured by death and intraventricular hemorrhage in preterm infants and compares the risks between calcium channel blockers and atosiban., Importance No trials to date have demonstrated the benefits of tocolysis on death and/or neonatal morbidity in preterm infants; tocolytics may affect the fetal blood-brain barrier. Objectives To assess the risks associated with tocolysis in women delivering prematurely as measured by death and/or intraventricular hemorrhage (IVH) in preterm infants and to compare the association of calcium channel blockers (CCBs) nifedipine and nicardipine hydrochloride vs atosiban used for tocolysis with death and/or IVH. Design, Settings, and Participants The French 2011 EPIPAGE-2 (Enquête Épidémiologique sur les Petits Âges Gestationnels) cohort was limited to mothers admitted for preterm labor without fever, who delivered from 24 to 31 weeks of gestation from April 1 through December 31, 2011. Groups of preterm infants with vs without tocolytic exposure and groups with atosiban vs CCB exposure were compared. Data analysis was performed from June 7, 2014, through September 3, 2017. Exposures Tocolytics. Main Outcomes and Measures The primary outcome was a composite of death and/or IVH in preterm infants. Secondary outcomes included death, IVH, and a composite of death and/or grades III to IV IVH. Results A total of 1127 mothers (mean [SD] age, 25.5 [6.0] years) experienced preterm labor and gave birth to 1343 preterm infants with a male to female ratio of 1.23 and mean (SD) gestational age of 27 (2.5) weeks. Of these, 789 mothers (70.0%) received tocolytics; 314 (39.8%) received only atosiban, and 118 (15.0%) received only a CCB. In the first analysis, the primary outcome (death and/or IVH) was not significantly different in preterm infants with vs without tocolytic exposure (183 of 363 [50.4%] vs 207 of 363 [57.0%]; relative risk [RR], 0.88; 95% CI, 0.77-1.01; P = .07). The secondary outcome (death and/or grades III-IV IVH) was significantly lower in preterm infants with vs without tocolytic exposure (92 of 363 [25.3%] vs 118 of 363 [32.5%]; RR, 0.78; 95% CI, 0.62-0.98; P = .03). Other outcomes did not differ significantly. In the secondary analysis, death and/or IVH was not significantly different in preterm infants with atosiban vs CCB exposure (96 of 214 [44.9%] vs 62 of 121 [51.2%]; RR, 0.88; 95% CI, 0.70-1.10; P = .26), nor was IVH (77 of 197 [39.1%] vs 48 of 106 [45.3%]; RR, 0.86; 95% CI, 0.66-1.13; P = .29). Conclusions and Relevance In this population-based study, findings suggest that tocolytics were associated with a reduction of death and severe IVH. Other studies are necessary to compare perinatal outcomes after use of atosiban vs CCBs.

BACKGROUND AND OBJECTIVE: CYP2C9 catalyzes the biotransformation of indomethacin to its inactive metabolite O-desmethylindomethacin (DMI). The aim of this work was to determine the effect of CYP2C9 polymorphisms on indomethacin metabolism in pregnant women. METHODS: Plasma concentrations of indomethacin and DMI at steady state were analyzed with a validated LC-MS/MS method. DNA was isolated from subject blood and buccal smear samples. Subjects were grouped by genotype for comparisons of pharmacokinetic parameters. RESULTS: For subjects with the *1/*2 genotype, the mean CL/F(ss) of indomethacin was 13.5 ± 7.7 L/h (n=4) and the mean metabolic ratio (AUC(DMI)/AUC(indomethacin)) was 0.291 ± 0.133. For subjects with the *1/*1 genotype, these values were 12.4 ± 2.7 L/h and 0.221 ± 0.078, respectively (n=14). Of note, we identified one subject who was a carrier of both the *3 and *4 alleles, resulting in an amino acid change (I359P) which has not been reported previously. This subject had a metabolic ratio of 0.390 and a steady-state apparent oral clearance of indomethacin (24.3 L/h) that was nearly double the wild-type clearance. CONCLUSION: Although our results are limited by sample size and are not statistically significant, these data suggest that certain genetic polymorphisms of CYP2C9 may lead to an increased metabolic ratio and an increase in the clearance of indomethacin. More data are needed to assess the impact of CYP2C9 genotype on the effectiveness of indomethacin as a tocolytic agent.

BACKGROUND: Uterine tachysystole (more than 5 contractions per 10 minutes in 2 consecutive intervals) is common during labour, particularly with use of labour‐stimulating agents. Tachysystole may reduce fetal oxygenation by interrupting maternal blood flow to the placenta during contractions. Reducing uterine contractions may improve placental blood flow, improving fetal oxygenation. This review aimed to evaluate the use of tocolytics to reduce or stop uterine contractions for improvement of the condition of the fetus in utero. This new review supersedes an earlier Cochrane Review on the same topic. OBJECTIVES: To assess the effects of the use of acute tocolysis during labour for uterine tachysystole or suspected fetal distress, or both, on fetal, maternal and neonatal outcomes. SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (2 February 2018), and reference lists of retrieved studies. SELECTION CRITERIA: Randomised controlled trials (RCTs) evaluating acute tocolysis for uterine tachysystole, intrapartum fetal distress, or both. DATA COLLECTION AND ANALYSIS: We used standard methods expected by Cochrane. MAIN RESULTS: We included eight studies (734 women), conducted in hospital settings, predominantly in high‐income countries (USA, Austria, Uruguay). Two trials were conducted in upper and lower middle‐income countries (South Africa, Sri Lanka). The hospital facilities all had the capacity to perform caesarean section. Overall, the studies had a low risk of bias, except for methods to maintain blinding. All of the trials used a selective beta(2) (ß(2))‐adrenergic agonist in one arm, however the drug used varied, as did the comparator. Limited information was available on maternal outcomes. Selective ß(2)‐adrenergic agonist versus no tocolytic agent, whilst awaiting emergency delivery There were two stillbirths, both in the no tocolytic control group (risk ratio (RR) 0.23, 95% confidence interval (CI) 0.01 to 4.55; 2 studies, 57 women; low‐quality evidence). One had gross hydrocephalus and the second occurred with vaginal delivery after waiting 55 minutes for caesarean section. The decision for caesarean section delivery was an inclusion criterion in both studies so we could not assess this as an outcome under this comparison. Abnormal fetal heart trace is probably lower with tocolytic treatment (RR 0.28, 95% CI 0.08 to 0.95; 2 studies, 43 women; moderate‐quality evidence). The effects on the number of babies with Apgar score below seven were uncertain (low‐quality evidence). Intravenous (IV) atosiban versus IV hexoprenaline (1 study, 26 women) One infant in the hexoprenaline group required > 24 hours in the neonatal intensive care unit (NICU) following a forceps delivery (RR 0.33, 95% CI 0.01 to 7.50; low‐quality evidence). There were no fetal or neonatal mortalities and no Apgar scores below seven. There was one caesarean delivery in the IV hexoprenaline group (RR 0.33, 95% CI 0.01 to 7.50; low‐quality evidence), and one case of abnormal fetal heart score in the atosiban group (RR 3.00, 95% CI 0.13 to 67.51; very low‐quality evidence). IV fenoterol bromhydrate versus emergency delivery (1 study, 390 women) No data were reported for perinatal death, severe morbidity or fetal or neonatal mortality. IV fenoterol probably increases the risk of caesarean delivery (RR 1.12, 95% CI 1.04 to 1.22; moderate‐quality evidence). Fenoterol may have little or no effect on the risk of Apgar scores below seven (RR 1.28, 95% CI 0.35 to 4.68; low‐quality evidence). IV hexoprenaline versus no tocolytic agent, whilst awaiting emergency delivery (1 study, 37 women) No data were reported for perinatal death or severe morbidity. There were two fetal deaths in the no tocolytic control group (RR 0.23, 95% CI 0.01 to 4.55; low‐quality evidence). The rate of caesarean delivery was not reported. There were two babies with Apgar scores below seven in the control group and none in the hexoprenaline group (RR 0.24, 95% CI 0.01 to 4.57; 35 women; low‐quality evidence). Subcutaneous terbutaline versus IV magnesium sulphate (1 study, 46 women) No data were reported for perinatal death, severe morbidity or fetal or neonatal mortality. The decision for caesarean section was an inclusion criterion, so we could not assess this. The effects on abnormal fetal heart trace are uncertain (very low‐quality evidence). Subcutaneous terbutaline with continuation of oxytocic infusion versus cessation of oxytocic infusion without tocolytic agent (1 study, 28 women) No data were reported for perinatal death, severe morbidity or fetal or neonatal mortality. There may be little or no difference in the rates of caesarean delivery in the subcutaneous terbutaline (8/15) and control groups (4/13) (RR 1.73, 95% CI 0.68 to 4.45; low‐quality evidence). There were no cases of Apgar scores below seven or abnormal fetal heart trace. Subcutaneous terbutaline versus no tocolytic agent, whilst awaiting emergency delivery (1 study, 20 women) No data were reported for perinatal death or severe morbidity. There were no fetal or neonatal mortalities. The decision for caesarean section was an inclusion criterion, so we could not assess this. There were two babies with Apgar scores below seven in the control group and none in the terbutaline group (RR 0.17, 95% CI 0.01 to 3.08; low‐quality evidence). IV terbutaline versus IV nitroglycerin (1 study, 110 women) No data were reported for perinatal death or severe morbidity or fetal or neonatal mortality. There may be little or no difference in the rates of caesarean delivery between the IV terbutaline (30/57) and control groups (29/53) (RR 0.96, 95% CI 0.68 to 1.36; low‐quality evidence). There were no cases of Apgar scores below seven. AUTHORS' CONCLUSIONS: There is insufficient evidence to determine the effects of tocolytics for uterine tachysystole or suspected fetal distress during labour. The clinical significance for some of the improvements in measures of fetal well‐being with tocolytics is unclear. The sample sizes were too small to detect effects on neonatal morbidity, mortality or serious adverse effects. The majority of studies are from high‐income countries in facilities with access to caesarean section, which may limit the generalisability of the results to lower‐resource settings, or settings where caesarean section is not available. Further well‐designed and adequately powered RCTs are required to evaluate clinically relevant indicators of maternal and neonatal morbidity and mortality.

Background Delayed interval intertwin delivery rates are expected to rise during the next years as potent and targeted tocolytic agents are employed and antenatal surveillance methods become more sophisticated and specific in predicting the critical delivery timepoint of optimal perinatal outcome. Case presentation We present a case of delayed intertwin delivery after delivery of the first twin due to premature prelabor rupture of the membranes. Maternal serum White Blood Cells and C-Reactive Protein levels remained high until delivery of the second twin (34 days after the first was delivered), although maternal temperature remained constant. The mother underwent close antenatal surveillance and she was hospitalized. She had an uncomplicated delivery of the second twin at 29+ 2 weeks by cesarean section due to an abnormal Non-Stress Test. Conclusion We strongly suggest future evaluation of maternal serum inflammatory markers among these rare cases as these could predict intraamniotic infection.

Background International guidelines recommend that tocolytic therapy be restricted to a single 48-h application. However, multiple cycles of tocolytic therapy and maintenance therapy that exceeds 48 h appear to play a role in daily clinical practice. We aimed to evaluate current trends in clinical practice with respect to treatment with tocolytic agents and to identify differences between evidence-based recommendations and daily clinical practice in Austria. Methods A prospective multicenter registry study was conducted from October 2013 through April 2015 in ten obstetrical departments in Austria. Women ≥18 years of age who received tocolytic therapy following a diagnosis of threatened preterm birth were included, and details were obtained regarding clinical characteristics, tocolytic therapy, and pregnancy outcome. Results A total of 309 women were included. We observed a median of 2 cycles of tocolytic therapy per patient (IQR 1–3) with a median duration of 2 days per cycle (IQR 2–5). Repeat tocolysis was administered in 41.7% of women, resulting in up to six tocolysis cycles; moreover, 40.8% of the first tocolysis cycles were maintenance tocolysis (i.e., longer than 48 h). Only 25.6% of women received one single 48-h tocolysis cycle in which they received antenatal corticosteroids for fetal lung maturation in accordance evidence-based recommendations. Conclusions Here, we report a clear disparity between evidence-based recommendations and daily practice with respect to tocolysis. We believe that the general practice of prescribing tocolytic therapy must be revisited. Furthermore, our findings highlight the need for contemporary studies designed to investigate the effectiveness of performing maintenance and/or repetitive tocolysis treatment. Electronic supplementary material The online version of this article (10.1186/s12884-018-2078-5) contains supplementary material, which is available to authorized users.

Introduction: To compare tocolysis with magnesium sulfate versus atosiban regarding the occurrence of short-term preterm labor and maternal side effects during and after open fetal myelomeningocele (MMC) repair. Material and Methods: A prospective nonrandomized cohort study was performed including 30 fetal MMC cases. The first 15 cases (group 1) received magnesium sulfate according to the MOMS protocol. In the following 15 cases (group 2), magnesium sulfate was substituted by atosiban. Chorioamniotic membrane separation (CMS), premature prelabor rupture of the fetal membranes (PPROM), preterm delivery Results: In both groups, one CMS but no PPROM was diagnosed Discussion: The use of atosiban resulted in an almost identical short-term uterine outcome without any serious maternal complications as seen when magnesium sulfate was given. Thus, the authors suggest using atosiban instead of magnesium sulfate in the context of open fetal surgery.

The aim of this study was to investigate the tocolytic properties of Ananas comosus extract in rat and human uterine tissue in vitro and in the rat in vivo. Organ bath technique was employed to perform functional studies in vitro. The PhysioTel transmitter was implanted in SD rats to measure the changes in intrauterine pressure (IUP) in vivo. Analyses of F2 was performed using LC-HRMS. F2 produced a non-selective inhibitory response on oxytocin, prostaglandin F2α, acetylcholine and KCl. The inhibitory activity of F2 on oxytocin-induced contraction was not attenuated by propranolol, TEA, glibenclamide and indomethacin. Nω-Nitro-L-arginine, a nitric oxide synthase inhibitor, suppressed the maximal tocolytic activity of F2 by 25%. DIDS, an inhibitor of chloride channels, appeared to suppress the relaxant effect of F2. F2 suppressed the oxytocin-induced contraction in Ca2+ free solution. The in vivo tocolytic activity of F2 and ritodrine were observed in non-pregnant rats during the estrous stage by suppressing the frequency and amplitude of IUP peaks following intrauterine administration. Chemical analysis confirmed the involvement of citric acid in the tocolytic activity of F2. However, another less polar fraction is essential to accompany citric acid to produce such potent inhibitory response of F2. It is likely that F2 exerted tocolytic activity by multiple mechanisms, including antagonizing L-type Ca2+ channels, interfering with the intracellular Ca2+ release mechanism and releasing nitric oxide. F2 would be a promising candidate to develop as a tocolytic agent.

Preterm premature rupture of membranes occurs in around 3% of pregnancies, and several aspects related to its management are still controversial. The objective of this update is to provide a detailed review of strategies aimed at reducing morbidity and mortality associated with this maternal condition. We will discuss the available evidence regarding the maternal use of antibiotics, the use of corticosteroids according to gestational age, the use of magnesium sulphate for fetal neuroprotection, the use of tocolytic agents, and the best moment for and route of delivery. This review also covers the effects of prolonged preterm premature rupture of membranes, infant morbidity and mortality in the short and long term, the harmful effects of antibiotics after delivery, including the effects on neurodevelopment and the presence of longterm chronic diseases.La ruptura prematura de membranas de pretérmino ocurre en, aproximadamente, el 3% de los embarazos y numerosos aspectos vinculados a su manejo continúan siendo controversiales. El objetivo de esta actualización es revisar en forma detallada las estrategias destinadas a disminuir la morbilidad y mortalidad asociadas a esta situación clínica en las madres. Se discutirá la evidencia disponible acerca del uso en las madres de antibióticos, corticoides a distintas edades gestacionales, sulfato de magnesio como neuroprotector fetal, tocolíticos y el momento óptimo y la vía de finalización del embarazo. Asimismo, se incluyen los efectos de la ruptura prolongada de membranas en prematuros, la mortalidad y morbilidad de los recién nacidos en el corto y largo plazo, los perjuicios de la administración de antibióticos luego del nacimiento con las secuelas en el neurodesarrollo y la presencia de enfermedades crónicas a largo plazo.

Introduction: The use of perioperative tocolytic agents in fetal surgery is imperative to prevent preterm labor. Indomethacin, a well-known tocolytic agent, can cause ductus arteriosus (DA) constriction. We sought to determine whether a relationship exists between preoperative indomethacin dosing and fetal DA constriction. Materials and Methods: This is an IRB-approved, single-center retrospective observational case series of 42 pregnant mothers who underwent open fetal myelomeningocele repair. Preoperatively, mothers received either 1 (QD) or 2 (BID) indomethacin doses. Maternal anesthetic drug exposures and fetal cardiac dysfunction measures were collected from surgical and anesthesia records and intraoperative fetal echocardiography. Pulsatility Index was used to calculate DA constriction severity. Comparative testing between groups was performed using t- and chi-square testing. Results: DA constriction was observed in all fetuses receiving BID indomethacin and in 71.4% of those receiving QD dosing (p = 0.0002). Severe DA constriction was observed only in the BID group (35.7%). QD indomethacin group received more intraoperative magnesium sulfate (p < 0.0001). Minimal fetal cardiac dysfunction (9.5%) and bradycardia (9.5%) were observed in all groups independent of indomethacin dosing. Conclusions: DA constriction was the most frequent and severe in the BID indomethacin group. QD indomethacin and greater magnesium sulfate dosing was associated with reduced DA constriction.