Effects of tocolysis with nifedipine or atosiban on child outcome: follow-up of the APOSTEL III trial

Tocolysis and Neurodevelopment of Children Born Very Preterm

Importance

Neurodevelopmental outcomes of very preterm children exposed to tocolytics are not well described.

Objective

To investigate whether tocolysis administered after spontaneous preterm labor is associated with neurodevelopmental outcomes at 5.5 years and to assess whether the type of tocolytic drug is associated with neurodevelopmental outcomes among infants exposed.

Design, Setting, and Participants

This prospective, national, population-based cohort study used data from the French Etude Épidémiologique sur les Petits Âges Gestationnels-2 cohort. Children who were alive and participated in an assessment at 5.5 years and whose mothers experienced spontaneous preterm labor without an infectious context and delivered at 24 to 31 weeks were eligible for this study. Recruitment occurred from March to December 2011. Follow-up at age 5.5 years was conducted from September 2016 to December 2017. Data analysis was performed from July 2023 through April 2024.

Exposures

The primary analysis examined tocolytics (yes vs no), and the secondary analysis examined the type of tocolytic (atosiban vs calcium channel blockers [CCBs]).

Main Outcome and Measure

The composite outcome neurodevelopmental disabilities included cerebral palsy; visual, hearing, and cognitive deficiencies; developmental coordination disorders; or behavioral problems.

Results

A total of 1055 mothers (mean [SD] age, 29.2 [5.7] years) had preterm labor without fever and gave birth to 1320 children (704 male [weighted percentage, 53.3%; 95% CI, 50.6%-56.1%]; mean [SD] gestational age, 28.8 [2.0] weeks). Overall, 776 mothers (weighted percentage, 73.5%; 95% CI, 70.8%-76.2%) received tocolytics; 136 mothers (weighted percentage, 17.9%; 95% CI, 15.3%-20.8%) received only a CCB, and 295 mothers (weighted percentage, 37.6%; 95% CI, 34.2%-41.0%) received only atosiban. From modified Poisson regression with propensity score matching, the risk of overall neurodevelopmental disabilities (mild, moderate, or severe) at 5.5 years did not differ between preterm children exposed and not exposed to tocolytics (relative risk [RR], 1.11; 95% CI, 0.85-1.45; P = .44) or in preterm infants exposed to atosiban compared with those exposed to CCBs (RR, 0.94; 95% CI, 0.67-1.32; P = .71).

Conclusions and Relevance

In this study, tocolytics were not associated with neurodevelopmental disabilities among very preterm children surviving at 5.5 years.

Atosiban versus placebo in the treatment of threatened preterm birth between 30 and 34 weeks gestation: study protocol of the 4-year APOSTEL 8 follow-up

INTRODUCTION

Currently, the majority of women worldwide with threatened preterm birth are treated with tocolytics. Although tocolytics can effectively delay birth for 48 hours, no tocolytic drug has convincingly been shown to improve neonatal outcomes and effects on long-term child development are unknown. The aim of this follow-up study of a placebo controlled randomised trial is to investigate the long-term effects of atosiban administration in case of threatened preterm birth on child's neurodevelopment and behaviour development, overall health and mortality.

METHODS AND ANALYSIS

This protocol concerns a follow-up study of the multicentre randomised double-blind placebo controlled APOSTEL 8 trial (NL61439.018.17, EudraCT-number 2017-001007-72). In this trial, women with threatened preterm birth (between 30 and 34 weeks of gestation) defined as uterine contractions with (1) a cervical length of <15 mm or (2) a cervical length of 15-30 mm and a positive fibronectin test or (3) in centres where cervical length measurement is not part of the local protocol: a positive fibronectin test or Actim-Partus test or (4) ruptured membranes, are randomised to atosiban or placebo for 48 hours. The primary outcome is a composite of perinatal mortality and severe neonatal morbidity. Children born to mothers who participated in the APOSTEL 8 study (n=760) will be eligible for follow-up at 4 years of corrected age and assessed using four parent-reported questionnaires. Primary outcomes are neurodevelopment and behaviour problems. Secondary outcomes are on child growth and general health. All outcomes will be compared between the atosiban and placebo group with OR and corresponding 95% CI. Analyses will be performed using the intention-to-treat approach.

ETHICS AND DISSEMINATION

The Medical Research Ethics Committee from Amsterdam UMC confirmed that de Medical Research Involving Human Subjects Act (Dutch WMO-law) did not apply to our study (W21_386 # 21.431). Results will be published in a peer-reviewed journal and shared with stakeholders and participants. This protocol is published before analysis of the results.

Tocolysis after preterm prelabor rupture of membranes and 5-year outcomes: a population-based cohort study

BACKGROUND

The administration of tocolytics after preterm prelabor rupture of membranes remains a controversial practice. In theory, reducing uterine contractility should delay delivery and allow for optimal antenatal management, thereby reducing the risks for prematurity and adverse consequences over the life course. However, tocolysis may be associated with neonatal death or long-term adverse neurodevelopmental outcomes, mainly related to prolonged fetal exposure to intrauterine infection or inflammation. In a previous study, we showed that tocolysis administration was not associated with short-term benefits. There are currently no data available to evaluate the impact of tocolysis on neurodevelopmental outcomes in school-aged children born prematurely in this clinical setting.

OBJECTIVE

This study aimed to investigate whether tocolysis administered after preterm prelabor rupture of membranes is associated with neurodevelopmental outcomes at 5.5 years of age.

STUDY DESIGN

We used data from a prospective, population-based cohort study of preterm births recruited in 2011 (referred to as the EPIPAGE-2 study) and for whom the results of a comprehensive medical and neurodevelopmental assessment of the infant at age 5.5 years were available. We included pregnant individuals with preterm prelabor rupture of membranes at 24 to 32 weeks' gestation in singleton pregnancies with a live fetus at the time of rupture, birth at 24 to 34 weeks' gestation, and participation of the infant in an assessment at 5.5 years of age. Exposure was the administration of any tocolytic treatment after preterm prelabor rupture of membranes. The main outcome was survival without moderate to severe neurodevelopmental disabilities at 5.5 years of age. Secondary outcomes included survival without any neurodevelopmental disabilities, cerebral palsy, full-scale intelligence quotient, developmental coordination disorders, and behavioral difficulties. A propensity-score analysis was used to minimize the indication bias in the estimation of the treatment effect on outcomes.

RESULTS

Overall, 596 of 803 pregnant individuals (73.4%) received tocolytics after preterm prelabor rupture of membranes. At the 5.5-year follow-up, 82.7% and 82.5% of the children in the tocolysis and no tocolysis groups, respectively, were alive without moderate to severe neurodevelopmental disabilities; 52.7% and 51.1%, respectively, were alive without any neurodevelopmental disabilities. After applying multiple imputations and inverse probability of treatment weighting, we found no association between the exposure to tocolytics and survival without moderate to severe neurodevelopmental disabilities (odds ratio, 0.93; 95% confidence interval, 0.55-1.60), survival without any neurodevelopmental disabilities (odds ratio, 1.02; 95% confidence interval, 0.65-1.61), or any of the other outcomes.

CONCLUSION

There was no difference in the neurodevelopmental outcomes at age 5.5 years among children with and without antenatal exposure to tocolysis after preterm prelabor rupture of membranes. To date, the health benefits of tocolytics remain unproven, both in the short- and long-term.

Atosiban-induced acute pulmonary edema: A rare but severe complication of tocolysis

Background

Atosiban is commonly used to delay premature labor in pregnant women and is thought to have few side effects.

Objectives

To report a case of acute pulmonary edema (APE) following administration of atosiban and conduct a systematic review to identify common characteristics and risk factors of atosiban-associated APE.

Methods

Searches were performed in Pubmed, Embase, and Web of Science using the keyword "Atosiban" combined with the terms "Pulmonary edema" or "Dyspnea" or "Hypoxia" on 9th July 2022. Only case reports of atosiban-associated APE were included without language restrictions. Data were extracted from the reports, and median, range, and percentages were calculated as applicable. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal checklist for case reports.

Results

Seven cases of atosiban-associated APE were included in the systematic review, including our case. APE occurred at a median gestational age of 32 + 6 weeks. Most patients were nulliparous (6/7, 85.7%) and were in multiple pregnancies (5/7, 71.4%). All patients were prescribed antenatal corticosteroids and tocolytics, with three (42.9%) receiving only atosiban and four (57.1%) receiving atosiban and other tocolytics. The median interval from starting atosiban administration to APE onset was about 40 h, and three patients (42.9%) showed symptoms 2-10 h after the end of atosiban treatment. Radiographic examinations (chest X-ray and/or computer tomography scan) confirmed APE in all patients and pleural effusion in four patients (57.1%). Five patients (71.4%) underwent emergency cesarean section, one patient (14.3%) with twin pregnancy had vaginal delivery with the help of suction cup and forceps, and another patient (14.3%) continued the pregnancy. All patients recovered well after administration of oxygen, diuresis, and other supportive therapy.

Conclusion

Atosiban may cause acute pulmonary edema in patients with underlying risk factors. This complication remains rare, but caution during tocolytic treatment using atosiban is recommended.

Pessary or progesterone to prevent preterm birth in women with short cervical length: protocol of the 4-6 year follow-up of a randomised controlled trial (Quadruple-P)

INTRODUCTION

Vaginal progesterone and a cervical pessary are both interventions that are investigated for the prevention of preterm birth (PTB). Thus far, beneficial or harmful effects of these interventions on long-term child health and development are described, but evidence is not robust enough to draw firm conclusions. With this follow-up study, we intent to investigate if progesterone or a pessary is superior for the prevention of PTB considering the child's health at 4-6 years of corrected age.

METHODS AND ANALYSIS

This study is a follow-up study of the Quadruple-P trial; a multicentre, randomised clinical trial (NL42926.018.13, Eudractnumber 2013-002884-24) which randomises women with an asymptomatic midtrimester short cervix to daily progesterone or a pessary for the prevention of PTB. All children born to mothers who participated in the Quadruple-P study (n=628 singletons and n=332 multiples) will be eligible for follow-up at 4-6 years of corrected age. Children will be assessed using parental questionnaires. Main outcomes are child (neuro)development and behaviour. Other outcomes include child mortality, growth and general health. A composite of adverse child outcomes will be compared between the progesterone and pessary groups reporting OR and the corresponding 95% CI. Analyses will be performed separately for singletons and multiples and using the intention-to-treat approach.

ETHICS AND DISSEMINATION

The Medical Research Ethics Committee from Amsterdam UMC confirmed that de Medical Research Involving Human Subjects Act (WMO) did not apply to our study (W20_481 #20.531). Results will be published in a peer-reviewed journal and shared with stakeholders and participants. This protocol is published before analysis of the results.

TRIAL REGISTRATION NUMBER

Dutch Trial Register (NL9646).

Hexoprenaline Compared with Atosiban as Tocolytic Treatment for Preterm Labor

Introduction Preterm birth is defined as a live birth before 37 weeks of gestation and is associated with increased neonatal morbidity and mortality. The aim of this study is to compare the efficacy of hexoprenaline and atosiban for short- and long-term tocolysis and their effects on neonatal and maternal outcomes.

Methods This retrospective cohort study included women with threatened preterm labor between 24 + 0 and 34 + 0 weeks of gestation without premature rupture of membranes. The tocolytic efficacy of hexoprenaline and atosiban was compared in women receiving one of the two medications for short- and long-term tocolysis. Continuous variables were compared using t-test or Mann–Whitney U test, as appropriate. Comparison of categorical variables between the two groups was done with χ ² test after Pearsonʼs and Fisherʼs exact test.

Results 761 women were enrolled in this study; 387 women received atosiban and 374 women received hexoprenaline as their primary tocolytic agent. Atosiban showed a higher efficacy as a primary tocolytic agent (p = 0.000) within 48 hours. As regards long-term tocolysis, there were no differences between the treatment groups (p = 0.466). Maternal side effects such as tachycardia (p = 0.018) or palpitations (p = 0.000) occurred more frequently after the administration of hexoprenaline, while there were no differences between the two drugs administered with regard to any other maternal or neonatal outcome parameter.

Conclusion Our retrospective study shows a significantly higher efficacy of atosiban in the first 48 hours, especially when administered at an early gestational age. There were no significant differences in terms of neonatal outcome but significantly more maternal adverse effects during the administration of hexoprenaline.

Tocolysis with nifedipine versus atosiban and perinatal outcome: an individual participant data meta-analysis

Background

Worldwide, nifedipine and atosiban are the two most commonly used tocolytic agents for the treatment of threatened preterm birth. The aim of this study was to evaluate the effectiveness of nifedipine and atosiban in an individual participant data meta-analysis (IPDMA).

Methods

We investigated the occurrence of adverse neonatal outcomes in women with threatened preterm birth by performing an IPDMA, and sought to identify possible subgroups in which one treatment may be preferred. We searched PubMed, Embase, and Cochrane for trials comparing nifedipine and atosiban for treatment of threatened preterm birth between 24^0/7 and 34^0/7 weeks’ gestational age. Primary outcome was a composite of perinatal mortality and neonatal morbidities including respiratory distress syndrome, intraventricular haemorrhage, periventricular leucomalacia, necrotising enterocolitis, and sepsis. Secondary outcomes included NICU admission, prolongation of pregnancy and GA at delivery. For studies that did not have the original databases available, metadata was used. This led to a two-stage meta-analysis that combined individual participant data with aggregate metadata.

Results

We detected four studies (N = 791 women), of which two provided individual participant data (N = 650 women). The composite neonatal outcome occurred in 58/364 (16%) after nifedipine versus 69/359 (19%) after atosiban (OR 0.76, 95%CI 0.47–1.23). Perinatal death occurred in 14/392 (3.6%) after nifedipine versus 7/380 (1.8%) after atosiban (OR 2.0, 95%CI 0.80–5.1).

Nifedipine results in longer prolongation of pregnancy, with a 18 days to delivery compared with 10 days for atosiban (HR 0.83 (96% CI 0.69–0.99)). NICU admission occurred less often after nifedipine (46%) than after atosiban (59%), (OR 0.32, 95%CI 0.14–0.75). The sensitivity analysis revealed no difference in prolongation of pregnancy for 48 hours (OR 1.0, 95% CI 0.73–1.4) or 7 days (OR 1.3, 95% CI 0.85–5.8) between nifedipine and atosiban. There was a non-significant higher neonatal mortality in the nifedipine-exposed group (OR 1.4, 95% CI 0.60–3.4).

Conclusions

In this IPDMA, we found no differences in composite outcome between nifedipine and atosiban in the treatment of threatened preterm birth. However, the non-significant higher mortality after administering nifedipine warrants further investigation of the use of nifedipine as a tocolytic drug.

Study registration

We conducted this study according to a prospectively prepared protocol, registered with PROSPERO (the International Prospective Register of Systematic Reviews) under CRD42016024244.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04854-1.

Short-Term Outcomes of Atosiban in the Treatment of Preterm Labour at the Sultan Qaboos University Hospital, Muscat, Oman: A tertiary care experience

Objectives

This study aimed to generate baseline evidence regarding the effectiveness of atosiban in delaying delivery by ≥48 hours among pregnant women presenting with threatened preterm labour (TPL). The secondary objective was to assess the relationship between atosiban success and various perinatal factors and neonatal outcomes.

Methods

This retrospective study was conducted between June 2008 and May 2018 at the Sultan Qaboos University Hospital, Muscat, Oman. The medical records of all pregnant women who received atosiban between 24–34 gestational weeks for TPL during this period were reviewed.

Results

A total of 159 women were included in the study. Atosiban was successful in delaying delivery by ≥48 hours in 130 cases (81.8%). Approximately half of the women (50.9%) achieved uterine quiescence in <12 hours. Failure to delay delivery by ≥48 hours was significantly lower among women with normal versus abnormal cervical findings (11.1% versus 25.6%; P = 0.023). Only 9.4% of women experienced minor side-effects. Mean birth weight (2,724.55 versus 1,707.59 g; P <0.001) and Apgar scores at 5 minutes (9.66 versus 8.28; P <0.001) were significantly higher among neonates delivered at ≥48 versus <48 hours post-atosiban, whereas the rate of neonatal respiratory distress syndrome was significantly lower (18.4% versus 81.6%; P <0.001).

Conclusion

Atosiban was highly effective in delaying delivery by ≥48 hours and resulted in few adverse maternal side-effects and neonatal outcomes. To the best of the authors’ knowledge, this is the first study conducted in Oman to evaluate the effectiveness of atosiban in preventing preterm labour.

Effects of tocolysis with nifedipine or atosiban on child outcome: follow-up of the APOSTEL III trial

OBJECTIVE

To compare the long-term effects of tocolysis with nifedipine or atosiban on child outcome at age 2.5-5.5 years.

DESIGN

The APOSTEL III trial was a multicentre randomised controlled trial that compared tocolysis with nifedipine or atosiban in 503 women with threatened preterm birth. Neonatal outcomes did not differ between both treatment arms, except for a higher incidence of intubation in the atosiban group.

METHODS

Parents were asked to complete four questionnaires regarding neurodevelopment, executive function, behaviour problems and general health.

MAIN OUTCOME MEASURES

The main long-term outcome measure was a composite of abnormal development at the age of 2.5-5.5 years.

RESULTS

Of the 426 women eligible for follow-up, 196 (46%) parents returned the questionnaires for 115 children in the nifedipine group and 110 children in the atosiban group. Abnormal development occurred in 32 children (30%) in the nifedipine group and in 38 children (38%) in the atosiban group (OR 0.74, 95% CI 0.41-1.34). The separate outcomes for neurodevelopment, executive function, behaviour, and general health showed no significant differences between the groups. Sensitivity analysis for all children of the APOSTEL III trial, including a comparison of deceased children, resulted in a higher rate of healthy survival in the nifedipine group (64 versus 54%), but there was no significant difference in the overall mortality rate (5.4 versus 2.7%). There were no significant subgroup effects.

CONCLUSION

Outcomes on broad child neurodevelopment, executive function, behaviour and general health were comparable in both groups. Neither nifedipine nor atosiban can be considered as the preferred treatment for women with threatened preterm birth.

TWEETABLE ABSTRACT

Nifedipine- and atosiban-exposed children had comparable long-term outcomes, including neurodevelopment, executive function and behaviour.