Induction of labor reduces cesarean delivery rates

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Non-medically indicated induction of labor may be associated with a decreased rate of cesarean births, along with some maternal and neonatal adverse outcomes, according to a recent study published in JAMA Network Open.

In 2019, the A Randomized Trial of Induction Versus Expectant Management (ARRIVE) trial was published, associating induction of labor with less cases of cesarean births and hypertensive spectrum disorders among nulliparous patients with low-risk pregnancies. Following the publication, rates of non-medically indicated induction of labor have increased.

It is not clear whether the results of the ARRIVE trial apply to the general US population. Cesarean birth is a significant factor in long-term health andhas greatly increased in the past 50 years. However, the rise in non-medically indicated induction of labor may have impacted cesarean birth and other obstetric outcomes.

To evaluate outcomes among pregnant women receiving non–medically indicated induction of labor at 39-weeks’ gestation, investigators conducted a retrospective cohort study. Singleton, nonanomalous births from January 1, 2007, to December 31, 2011, were gathered from the California Vital Statistics Birth Certificate Data and examined in 2021.

Included births were singleton, nonanomalous, of nulliparous individuals, and at 39 0/7 to 41 6/7 weeks of gestation. Births to pregnant individuals with comorbid conditions and those missing data for induction of labor or hospital type were excluded, along withbreech presentation, placenta previa, stillbirths, and elective or planned cesarean birth.

Hospital characteristics included locations, obstetric volume, and teaching status. Rural-urban commuting area codes determined location, and the presence of an obstetrics and gynecology residency program determined teaching status. Obstetric volume was categorized by low-volume, medium-volume, and high-volume categories based on births per year.

Cesarean birth was the primary outcome of the study, measured using birth certificate, procedural codes, and International Classification of Diseases, Ninth Revision codes. Perinatal and neonatal outcomes were measured as secondary outcomes.

Covariates included demographic characteristics such as age, race and ethnicity, body mass index (BMI), educational attainment, insurance type, and prenatal care attendance. Demographic characteristics were compared between non-medically indicated induction of labor and expectant management in rural and urban settings.

Of the 455,044 births included in the study, 5.3% were from non-medically indicated induction of labor. Differences were reported in average BMI between non-medically indicated induction of labor and expectant management, along with significant differences in age, race and ethnicity, prenatal care attendance, and insurance type in urban settings.

The odds of cesarean birth were significantly lowered following non-medically indicated induction of labor, with greater reductions in odds seen in rural hospitals. In urban hospitals, odds of maternal outcomes such as severe maternal morbidity, chorioamnionitis, postpartum hemorrhage, operative vaginal birth, and obstetric anal sphincter injury were reduced.

Neonatal outcomes such as neonatal intensive care unit admission 24 hours or more postpartum and respiratory distress syndrome also saw lower odds in urban hospitals than in rural hospitals. Adverse neonatal outcomes were also less likely for non-medically indicated induction of labor in hospitals of all volumes.

Medium- and high-volume hospitals had decreased odds of cesarean birth following non-medically indicated induction of labor. Community and teaching hospitals both saw significant reductions in the odds of cesarean birth following non-medically indicated induction of labor. Community hospitals also saw reduced odds of adverse maternal and neonatal outcomes.

Cesarean birth rates were reduced following non-medically indicated induction of labor in hospitals of various locations, teaching statuses, and sizes. Maternal and neonatal adverse outcomes were also reduced in these settings, indicating benefits for induction of labor in low-risk pregnancies.

Reference

Hersh AR, Bullard KA, Garg B, Arora M, Mischkot BF, Caughey AB. Analysis of obstetric outcomes by hospital location, volume, and teaching status associated with non–medically indicatedinduction of labor at 39 weeks. JAMA Netw Open. 2023;6(4):e239167. doi:10.1001/jamanetworkopen.2023.9167