Dataset Information

Outcomes of elective induction of labour compared with expectant management: population based study.

ABSTRACT:

Objective

To determine neonatal outcomes (perinatal mortality and special care unit admission) and maternal outcomes (mode of delivery, delivery complications) of elective induction of labour compared with expectant management.

Design

Retrospective cohort study using an unselected population database.

Setting

Consultant and midwife led obstetric units in Scotland 1981-2007.

Participants

1,271,549 women with singleton pregnancies of 37 weeks or more gestation.

Interventions

Outcomes of elective induction of labour (induction of labour with no recognised medical indication) at 37, 38, 39, 40, and 41 weeks' gestation compared with those of expectant management (continuation of pregnancy to either spontaneous labour, induction of labour or caesarean section at a later gestation).

Main outcome measures

Extended perinatal mortality, mode of delivery, postpartum haemorrhage, obstetric anal sphincter injury, and admission to a neonatal or special care baby unit. Outcomes were adjusted for age at delivery, parity, year of birth, birth weight, deprivation category, and, where appropriate, mode of delivery.

Results

At each gestation between 37 and 41 completed weeks, elective induction of labour was associated with a decreased odds of perinatal mortality compared with expectant management (at 40 weeks' gestation 0.08% (37/44,764) in the induction of labour group versus 0.18% (627/350,643) in the expectant management group; adjusted odds ratio 0.39, 99% confidence interval 0.24 to 0.63), without a reduction in the odds of spontaneous vertex delivery (at 40 weeks' gestation 79.9% (35,775/44,778) in the induction of labour group versus 73.7% (258,665/350,791) in the expectant management group; adjusted odds ratio 1.26, 1.22 to 1.31). Admission to a neonatal unit was, however, increased in association with elective induction of labour at all gestations before 41 weeks (at 40 weeks' gestation 8.0% (3605/44,778) in the induction of labour group compared with 7.3% (25,572/350,791) in the expectant management group; adjusted odds ratio 1.14, 1.09 to 1.20).

Conclusion

Although residual confounding may remain, our findings indicate that elective induction of labour at term gestation can reduce perinatal mortality in developed countries without increasing the risk of operative delivery.

SUBMITTER: Stock SJ

PROVIDER: S-EPMC3349781 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:ObjectiveTo assess adverse perinatal outcomes and caesarean section of low-risk women receiving elective induction of labour at 41 weeks or expectant management until 42 weeks according to their preferred and actual management strategy.DesignMulticentre prospective cohort study alongside RCT.Setting90 midwifery practices and 12 hospitals in the Netherlands.Population3642 low-risk women with uncomplicated singleton late-term pregnancy.Main outcome measuresComposite adverse outcome (perinatal death, Apgar score 5' < 7, NICU admission, meconium aspiration syndrome), composite severe adverse perinatal outcome (all above with Apgar score 5' < 4 instead of < 7) and caesarean section.ResultsFrom 2012-2016, 3642 women out of 6088 eligible women for the INDEX RCT, participated in the cohort study for observational data collection (induction of labour n = 372; expectant management n = 2174; unknown preference/management strategy n = 1096).Adverse perinatal outcome occurred in 1.1 % (4/372) in the induction group versus 1.9 % (42/2174) in the expectant group (adjRR 0.56; 95 %CI: 0.17-1.79), with severe adverse perinatal outcome occurring in 0.3 % (1/372) versus 1.0 % (22/2174), respectively (adjRR 0.39; 95 % CI: 0.05-2.88). There were no stillbirths among all 3642 women; one neonatal death occurred in the unknown preference/management group. Caesarean section rates were 10.5 % (39/372) after induction and 8.9 % (193/2174) after expectant management (adjRR 1.32; 95 % CI: 0.95-1.84).A higher incidence of adverse perinatal outcome was observed in nulliparous compared to multiparous women. Nulliparous 1.8 % (3/170) in the induction group versus 2.6 % (30/1134) in the expectant management group (adjRR 0.58; 95 % CI 0.14-2.41), multiparous 0.5 % (1/201) versus 1.1 % (11/1039) (adjRR 0.54; 95 % CI 0.07-24.19). One maternal death due to amniotic fluid embolism occurred after elective induction at 41 weeks + 6 days.ConclusionIn this cohort study among low-risk women receiving the policy of their preference in late-term pregnancy, a non-significant difference was found between induction of labour at 41 weeks and expectant management until 42 weeks in absolute risks of composite adverse (1.1 % versus 1.9 %) and severe adverse (0.3 % versus 1.0 %) perinatal outcome. The risks in this cohort study were lower than in the trial setting. There were no stillbirths among all 3642 women. Caesarean section rates were comparable.

Project description:ObjectiveTo evaluate characteristics associated with adverse outcomes in low-risk nulliparous women randomized to elective labor induction at 39 weeks of gestation or expectant management.MethodsWe conducted a secondary analysis of women randomized during the 38th week to induction at 39 weeks of gestation or expectant management. Deliveries before 39 weeks of gestation and those not adherent to study protocol or with fetal anomalies were excluded. A composite of adverse outcomes (perinatal death or severe neonatal complications), third- or fourth-degree lacerations, and postpartum hemorrhage were evaluated. Log binomial regression models estimated relative risks and 95% CIs for associations of outcomes with patient characteristics including randomly assigned treatment group. Interactions between patient characteristics and treatment group were tested.ResultsOf 6,096 women with outcome data, 5,007 (82.1%) met criteria for inclusion in this analysis. Frequency of the perinatal composite was 252 (5.0%), 166 (3.3%) for third- or fourth-degree perineal laceration, and 237 (4.7%) for postpartum hemorrhage. In multivariable analysis, intended labor induction at 39 weeks of gestation was associated with a reduced perinatal composite outcome (4.1% vs 6.0%; adjusted relative risk [aRR] 0.71; 95% CI 0.55-0.90), whereas increasing body mass index (BMI) was associated with an increased perinatal composite outcome (aRR 1.04/unit increase; 95% CI 1.02-1.05). Decreased risk of third- or fourth-degree perineal laceration was observed with increasing BMI (aRR 0.96/unit increase; 95% CI 0.93-0.98) and in Black women compared with White women (1.2% vs 3.9%; aRR 0.34; 95% CI 0.19-0.60). Increased risk of postpartum hemorrhage was observed in Hispanic women compared with White women (6.3% vs 4.0%; aRR 1.64; 95% CI 1.18-2.29). Patient characteristics associated with adverse outcomes were similar between treatment groups (P for interaction >.05).ConclusionCompared with expectant management, intended induction at 39 weeks of gestation was associated with reduced risk of adverse perinatal outcome. Patient characteristics associated with adverse outcomes were few and similar between groups.Clinical trial registrationClinicalTrials.gov, NCT01990612.

Project description:BackgroundGestational diabetes (GDM) is one of the most common complications of pregnancies affecting around 7% of women. This clinical condition is associated with an increased risk of developing fetal macrosomia and is related to a higher incidence of caesarean section in comparison to the general population. Strong evidence indicating the best management between induction of labour at term and expectant monitoring are missing.Methods/designPregnant women with singleton pregnancy in vertex presentation previously diagnosed with gestational diabetes will be asked to participate in a multicenter open-label randomized controlled trial between 38+0 and 39+0 gestational weeks. Women will be recruited in the third trimester in the outpatient clinic or in the Day Assessment Unit according to local protocols. Women who opt to take part will be randomized according to induction of labour or expectant management for spontaneous delivery. Patients allocated to the induction group will be admitted to the obstetric ward and offered induction of labour via use of prostaglandins, Foley catheter or oxytocin (depending on clinical conditions). Women assigned to the expectant arm will be sent to their domicile where they will be followed up until delivery, through maternal and fetal wellbeing monitoring twice weekly. The primary study outcome is the Caesarean section (C-section) rate, whilst secondary measurements are maternal and neonatal outcomes. A total sample of 1760 women (880 each arm) will be recruited to identify a relative difference between the two arms equal to 20% in favour of induction, with concerns to C-section rate. Data will be collected until mothers and newborns discharge from the hospital. Analysis of the outcome measures will be carried out by intention to treat.DiscussionThe present trial will provide evidence as to whether or not, in women affected by gestational diabetes, induction of labour between 38+0 and 39+0 weeks is an effective management to ameliorate maternal and neonatal outcomes. The primary objective is to determine whether caesarean section rate could be reduced among women undergoing induction of labour, in comparison to patients allocated to expectant monitoring. The secondary objective consists of the assessment and comparison of maternal and neonatal outcomes in the two study arms. .

Project description:ObjectiveTo evaluate if induction of labour at 41 weeks improves perinatal and maternal outcomes in women with a low risk pregnancy compared with expectant management and induction of labour at 42 weeks.DesignMulticentre, open label, randomised controlled superiority trial.Setting14 hospitals in Sweden, 2016-18.Participants2760 women with a low risk uncomplicated singleton pregnancy randomised (1:1) by the Swedish Pregnancy Register. 1381 women were assigned to the induction group and 1379 were assigned to the expectant management group.InterventionsInduction of labour at 41 weeks and expectant management and induction of labour at 42 weeks.Main outcome measuresThe primary outcome was a composite perinatal outcome including one or more of stillbirth, neonatal mortality, Apgar score less than 7 at five minutes, pH less than 7.00 or metabolic acidosis (pH <7.05 and base deficit >12 mmol/L) in the umbilical artery, hypoxic ischaemic encephalopathy, intracranial haemorrhage, convulsions, meconium aspiration syndrome, mechanical ventilation within 72 hours, or obstetric brachial plexus injury. Primary analysis was by intention to treat.ResultsThe study was stopped early owing to a significantly higher rate of perinatal mortality in the expectant management group. The composite primary perinatal outcome did not differ between the groups: 2.4% (33/1381) in the induction group and 2.2% (31/1379) in the expectant management group (relative risk 1.06, 95% confidence interval 0.65 to 1.73; P=0.90). No perinatal deaths occurred in the induction group but six (five stillbirths and one early neonatal death) occurred in the expectant management group (P=0.03). The proportion of caesarean delivery, instrumental vaginal delivery, or any major maternal morbidity did not differ between the groups.ConclusionsThis study comparing induction of labour at 41 weeks with expectant management and induction at 42 weeks does not show any significant difference in the primary composite adverse perinatal outcome. However, a reduction of the secondary outcome perinatal mortality is observed without increasing adverse maternal outcomes. Although these results should be interpreted cautiously, induction of labour ought to be offered to women no later than at 41 weeks and could be one (of few) interventions that reduces the rate of stillbirths.Trial registrationCurrent Controlled Trials ISRCTN26113652.

Project description:ObjectiveTo compare induction of labour at 41 weeks with expectant management until 42 weeks in low risk women.DesignOpen label, randomised controlled non-inferiority trial.Setting123 primary care midwifery practices and 45 hospitals (secondary care) in the Netherlands, 2012-16.Participants1801 low risk women with an uncomplicated singleton pregnancy: randomised to induction (n=900) or to expectant management until 42 weeks (n=901).InterventionsInduction at 41 weeks or expectant management until 42 weeks with induction if necessary.Primary outcome measuresPrimary outcome was a composite of perinatal mortality and neonatal morbidity (Apgar score <7 at five minutes, arterial pH <7.05, meconium aspiration syndrome, plexus brachialis injury, intracranial haemorrhage, and admission to a neonatal intensive care unit (NICU). Secondary outcomes included maternal outcomes and mode of delivery. The null hypothesis that expectant management is inferior to induction was tested with a non-inferiority margin of 2%.ResultsMedian gestational age at delivery was 41 weeks+0 days (interquartile range 41 weeks+0 days-41 weeks+1 day) for the induction group and 41 weeks+2 days (41 weeks+0 days-41 weeks+5 days) for the expectant management group. The primary outcome was analysed for both the intention-to-treat population and the per protocol population. In the induction group, 15/900 (1.7%) women had an adverse perinatal outcome versus 28/901 (3.1%) in the expectant management group (absolute risk difference -1.4%, 95% confidence interval -2.9% to 0.0%, P=0.22 for non-inferiority). 11 (1.2%) infants in the induction group and 23 (2.6%) in the expectant management group had an Apgar score <7 at five minutes (relative risk (RR) 0.48, 95% CI 0.23 to 0.98). No infants in the induction group and three (0.3%) in the expectant management group had an Apgar score <4 at five minutes. One fetal death (0.1%) occurred in the induction group and two (0.2%) in the expectant management group. No neonatal deaths occurred. 3 (0.3%) neonates in the induction group versus 8 (0.9%) in the expectant management group were admitted to an NICU (RR 0.38, 95% CI 0.10 to 1.41). No significant difference was found in composite adverse maternal outcomes (induction n=122 (13.6%) v expectant management n=102 (11.3%)) or in caesarean section rate (both groups n=97 (10.8%)).ConclusionsThis study could not show non-inferiority of expectant management compared with induction of labour in women with uncomplicated pregnancies at 41 weeks; instead a significant difference of 1.4% was found for risk of adverse perinatal outcomes in favour of induction, although the chances of a good perinatal outcome were high with both strategies and the incidence of perinatal mortality, Apgar score <4 at five minutes, and NICU admission low.Trial registrationNetherlands Trial Register NTR3431.

Project description:A recent randomised controlled trial (RCT) demonstrated that induction of labour at 39 weeks of gestational age has no short-term adverse effect on the mother or infant among nulliparous women aged ?35 years. However, the trial was underpowered to address the effect of routine induction of labour on the risk of perinatal death. We aimed to determine the association between induction of labour at ?39 weeks and the risk of perinatal mortality among nulliparous women aged ?35 years.We used English Hospital Episode Statistics (HES) data collected between April 2009 and March 2014 to compare perinatal mortality between induction of labour at 39, 40, and 41 weeks of gestation and expectant management (continuation of pregnancy to either spontaneous labour, induction of labour, or caesarean section at a later gestation). Analysis was by multivariable Poisson regression with adjustment for maternal characteristics and pregnancy-related conditions. Among the cohort of 77,327 nulliparous women aged 35 to 50 years delivering a singleton infant, 33.1% had labour induced: these women tended to be older and more likely to have medical complications of pregnancy, and the infants were more likely to be small for gestational age. Induction of labour at 40 weeks (compared with expectant management) was associated with a lower risk of in-hospital perinatal death (0.08% versus 0.26%; adjusted risk ratio [adjRR] 0.33; 95% CI 0.13-0.80, P = 0.015) and meconium aspiration syndrome (0.44% versus 0.86%; adjRR 0.52; 95% CI 0.35-0.78, P = 0.002). Induction at 40 weeks was also associated with a slightly increased risk of instrumental vaginal delivery (adjRR 1.06; 95% CI 1.01-1.11, P = 0.020) and emergency caesarean section (adjRR 1.05; 95% CI 1.01-1.09, P = 0.019). The number needed to treat (NNT) analysis indicated that 562 (95% CI 366-1,210) inductions of labour at 40 weeks would be required to prevent 1 perinatal death. Limitations of the study include the reliance on observational data in which gestational age is recorded in weeks rather than days. There is also the potential for unmeasured confounders and under-recording of induction of labour or perinatal death in the dataset.Bringing forward the routine offer of induction of labour from the current recommendation of 41-42 weeks to 40 weeks of gestation in nulliparous women aged ?35 years may reduce overall rates of perinatal death.