Dataset Information

Elective Labor Induction at 39 Weeks of Gestation Compared With Expectant Management: Factors Associated With Adverse Outcomes in Low-Risk Nulliparous Women.

ABSTRACT:

Objective

To evaluate characteristics associated with adverse outcomes in low-risk nulliparous women randomized to elective labor induction at 39 weeks of gestation or expectant management.

Methods

We 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.

Results

Of 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).

Conclusion

Compared 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 registration

ClinicalTrials.gov, NCT01990612.

SUBMITTER: El-Sayed YY

PROVIDER: S-EPMC7529933 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:ObjectiveTo develop models to predict vaginal delivery in low-risk, nulliparous women contemplating elective induction of labor or expectant management at 39 weeks of gestation.MethodsWe conducted a secondary analysis of a randomized controlled trial of planned elective induction of labor at 39 weeks of gestation compared with expectant management for low-risk nulliparous women. Two groups were included for this analysis: 1) women who were randomized to the induction of labor group and underwent elective induction at 39 0/7-39 4/7 weeks of gestation and 2) women who were randomized to the expectant management group who experienced spontaneous labor or medically indicated delivery (including postterm). Multivariable logistic regression models were developed for each group using patient characteristics that would be available at the time of counseling. Model selection was based on k-fold cross-validation using backward elimination and variables that remained significant at P<.05 were retained. To compare estimated with observed rates, the elective induction of labor model was then applied to each woman in both groups to estimate individualized predicted probabilities of vaginal delivery with elective induction of labor.ResultsOf 6,106 women enrolled in the trial, 4,661 met criteria for this analysis. Vaginal delivery occurred in 80.6% of the 2,153 women in the elective induction of labor group and 77.2% of the 2,508 women in the expectant management group (P=.005). The final elective induction of labor model included age, height, weight, and modified Bishop score (area under the receiver operating characteristic curve [AUROC] 0.72, 95% CI 0.70-0.75). The same variables were included in the final expectant management model (AUROC 0.70, 95% CI 0.67-0.72). Across the range of predicted probability deciles derived from the elective induction of labor model, almost all women who underwent elective induction of labor at 39 weeks of gestation had a higher observed chance of vaginal delivery than expectant management.ConclusionIrrespective of the individual predicted chance of vaginal delivery from elective induction of labor at 39 weeks of gestation, vaginal delivery is generally more frequent if elective induction of labor is undertaken rather than expectant management. These data can be used to counsel nulliparous women regarding their "customized" chances of vaginal delivery as they choose between elective induction of labor or expectant management at 39 weeks of gestation.Clinical trial registrationClinicalTrials.gov, NCT01990612.

Project description:ObjectiveOptimal management of pregnancies at 39 weeks gestational age is unknown. Therefore, we sought to perform a comparative effectiveness analysis of elective induction of labor (eIOL) at 39 weeks among nulliparous women with non-anomalous singleton, vertex fetuses as compared to expectant management (EM) which included IOL for medical or obstetric indications or at 41 weeks in undelivered mothers.Materials and methodsA Monte Carlo micro-simulation model was constructed modeling two mutually exclusive health states: eIOL at 39 weeks, or EM with IOL for standard medical or obstetrical indications or at 41 weeks if undelivered. Health state distribution probabilities included maternal and perinatal outcomes and were informed by a review of the literature and data derived from the Consortium of Safe Labor. Analyses investigating preferences for maternal versus infant health were performed using weighted utilities. Primary outcome was determining which management strategy posed less maternal and neonatal risk. Secondary outcomes were rates of cesarean deliveries, maternal morbidity and mortality, stillbirth, neonatal morbidity and mortality, and preferences regarding the importance of maternal and perinatal health.ResultsA management strategy of eIOL at 39 weeks resulted in less maternal and neonatal risk as compared to EM with IOL at 41 weeks among undelivered patients. Cesarean section rates were higher in the EM arm (35.9% versus 13.9%, p<0.01). When analysis was performed only on patients with an unfavorable cervix, 39 week eIOL still resulted in fewer cesarean deliveries as compared to EM (8.0% versus 26.1%, p<0.01). There was no statistical difference in maternal mortality (eIOL 0% versus EM 0.01%, p = 0.32) but there was an increase in maternal morbidity among the EM arm (21.2% versus 16.5, p<0.01). There were more stillbirths (0.13% versus 0%, p<0.0003), neonatal deaths (0.25% versus 0.12%, p< 0.03), and neonatal morbidity (12.1% versus 9.4%, p<0.01) in the EM arm as compared to the eIOL arm. Preference modeling revealed that 39 week eIOL was favored over EM.Conclusions and relevanceMathematical modeling revealed that eIOL at 39 weeks resulted in lower population risks as compared to EM with induction of labor at 41 weeks. Specifically, eIOL at 39 weeks resulted in a lower cesarean section rate, lower rates of maternal morbidity, fewer stillbirths and neonatal deaths, and lower rates of neonatal morbidity.

Project description:ImportanceElective induction of labor at 39 weeks of gestation is common. Thus, there is a need to assess maternal labor-related complications and neonatal outcomes associated with elective induction of labor.ObjectiveTo examine maternal labor-related complications and neonatal outcomes following elective induction of labor at 39 weeks compared with expectant management.Data sourcesA systematic review of the literature was conducted using the MEDLINE (Ovid), Embase (Ovid), Cochrane Central Library, World Health Organization, and ClinicalTrials.gov databases and registries to search for articles published between database inception and December 8, 2022.Study selectionThis systematic review and meta-analysis included randomized clinical trials, cohort studies, and cross-sectional studies reporting perinatal outcomes following induction of labor at 39 weeks vs expectant management.Data extraction and synthesisTwo reviewers independently assessed study eligibility, extracted data, and assessed studies for bias. Pooled odds ratios (ORs) and 95% CIs were calculated using a random-effects model. This study is reported per the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 guideline, and the protocol was prospectively registered with PROSPERO.Main outcomes and measuresMaternal outcomes of interest included emergency cesarean section, perineal injury, postpartum hemorrhage, and operative vaginal birth. Neonatal outcomes of interest included admission to the neonatal intensive care unit, low 5-minute Apgar score (<7) after birth, macrosomia, and shoulder dystocia.ResultsOf the 5827 records identified in the search, 14 studies were eligible for inclusion in this review. These studies reported outcomes for 1 625 899 women birthing a singleton pregnancy. Induction of labor at 39 weeks of gestation was associated with a 37% reduced likelihood of third- or fourth-degree perineal injury (OR, 0.63 [95% CI, 0.49-0.81]), in addition to reductions in operative vaginal birth (OR, 0.87 [95% CI, 0.79-0.97]), macrosomia (OR, 0.66 [95% CI, 0.48-0.91]), and low 5-minute Apgar score (OR, 0.62 [95% CI, 0.40-0.96]). Results were similar when confined to multiparous women only, with the addition of a substantial reduction in the likelihood of emergency cesarean section (OR, 0.61 [95% CI, 0.38-0.98]) and no difference in operative vaginal birth (OR, 1.01 [95% CI, 0.84-1.21]). However, among nulliparous women only, induction of labor was associated with an increased likelihood of shoulder dystocia (OR, 1.22 [95% CI, 1.02-1.46]) compared with expectant management.Conclusions and relevanceIn this study, induction of labor at 39 weeks was associated with improved maternal labor-related and neonatal outcomes. However, among nulliparous women, induction of labor was associated with shoulder dystocia. These results suggest that elective induction of labor at 39 weeks may be safe and beneficial for some women; however, potential risks should be discussed with nulliparous women.

Project description:ObjectiveTo estimate whether the frequency of adverse maternal and neonatal outcomes differs between low-risk nulliparous and multiparous women at 39-41 weeks of gestation.MethodsThis is a secondary analysis of an observational obstetrics cohort of maternal-neonatal dyads at 25 hospitals. Low-risk women with nonanomalous singletons who delivered between 39 0/7 and 41 6/7 weeks of gestation were included. The composite neonatal adverse outcome included 5-minute Apgar score less than five, ventilator support or cardiopulmonary resuscitation, seizure, hypoxic ischemic encephalopathy, sepsis, bronchopulmonary dysplasia, persistent pulmonary hypertension, necrotizing enterocolitis, birth injury or perinatal death. The composite maternal adverse outcome included infection, third- or fourth-degree perineal laceration, thromboembolism, transfusion of blood products, or maternal death. Small for gestational age (SGA), large for gestational age (LGA), and shoulder dystocia requiring maneuvers were also evaluated. Multivariable regression was used to estimate adjusted relative risks (aRRs) and adjusted odds ratios (aORs) with 95% CIs.ResultsOf the 115,502 women in the overall cohort, 39,870 (34.5%) met eligibility criteria for this analysis; 18,245 (45.8%) were nulliparous. The risk of the composite neonatal adverse outcome (1.5% vs 1.0%, aRR 1.80, 95% CI 1.48-2.19), composite maternal adverse outcome (15.1% vs 3.3%, aRR 5.04, 95% CI 4.62-5.49), and SGA (8.9% vs 5.8%, aOR 1.45, 95% CI 1.33-1.57) was significantly higher in nulliparous than multiparous patients. The risk of LGA (aOR 0.65, 95% CI 0.60-0.71) and shoulder dystocia with maneuvers (aRR 0.68, 95% CI 0.60-0.77) was significantly lower in nulliparous rather than multiparous patients.ConclusionThe risk of composite adverse outcomes and SGA among low-risk nulliparous women at 39-41 weeks of gestation is significantly higher than among multiparous counterparts. However, nulliparous women had a lower risk of shoulder dystocia with maneuvers and LGA.

Project description:ObjectiveTo 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.DesignRetrospective cohort study using an unselected population database.SettingConsultant and midwife led obstetric units in Scotland 1981-2007.Participants1,271,549 women with singleton pregnancies of 37 weeks or more gestation.InterventionsOutcomes 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 measuresExtended 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.ResultsAt 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).ConclusionAlthough 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.

Project description:ObjectiveTo compare health care medical resource utilization in low-risk nulliparous pregnancies according to body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) categories.MethodsThis is a secondary analysis of a multicenter randomized controlled trial of induction of labor between 39 0/7 39 and 4/7 weeks of gestation compared with expectant management in low-risk nulliparous pregnant people, defined as those without standard obstetric indications for delivery at 39 weeks. Body mass index at randomization was categorized into four groups (lower than 25, 25-29, 30-39, and 40 or higher). The primary outcome of this analysis was time spent in the labor and delivery department from admission to delivery. Secondary outcomes included length of stay (LOS) postdelivery, total hospital LOS, and antepartum, intrapartum, and postpartum resource utilization, which were defined a priori. Multivariable generalized linear modeling and logistic regressions were performed, and 99% CIs were calculated.ResultsA total of 6,058 pregnant people were included in the analysis; 640 (10.6%) had BMIs of lower than 25, 2,222 (36.7%) had BMIs between 25 and 29, 2,577 (42.5%) had BMIs of 30-39, and 619 (10.2%) had BMIs of 40 or higher. Time spent in the labor and delivery department increased from 15.1±9.2 hours for people with BMIs of lower than 25 to 23.5±13.6 hours for people with BMIs of 40 or higher, and every 5-unit increase in BMI was associated with an average 9.8% increase in time spent in the labor and delivery department (adjusted estimate per 5-unit increase in BMI 1.10, 99% CI 1.08-1.11). Increasing BMI was not associated with an increase in antepartum resource utilization, except for blood tests and urinalysis. However, increasing BMI was associated with higher odds of intrapartum resource utilization, longer total hospital LOS, and postpartum resource utilization. For example, every 5-unit increase in BMI was associated with an increase of 26.1% in the odds of antibiotic administration, 57.6% in placement of intrauterine pressure catheter, 5.1% in total inpatient LOS, 31.0 in postpartum emergency department visit, and 23.9% in postpartum hospital admission.ConclusionAmong low-risk nulliparous people, higher BMI was associated with longer time from admission to delivery, total hospital LOS, and more frequent utilization of intrapartum and postpartum resources.Clinical trial registrationClinicalTrials.gov, NCT01990612.