Inducing labor at 39 weeks reduces probability of C sections, complications

Elective induction of labor (eIOL) at 39 weeks results in lower risk of cesarean delivery and other complications including maternal morbidity, stillbirths, and neonatal morbidity, compared to induction of labor at 41 weeks, suggests a study. The study was published in the journal PLOS ONE.

The timing of delivery is a vital component of a healthy pregnancy. Preterm birth is the leading cause of neonatal morbidity and mortality, whereas late-term and post-term pregnancies are associated with increased maternal, fetal and neonatal risks. Uncertainty exists over the optimal timing of delivery among pregnancies between 39 and 41 weeks gestation.

Therefore, this study was conducted by Charles J. Lockwood, senior vice president for USF Health and dean of the Morsani College of Medicine, and colleagues, with the objective to perform a comparative effectiveness analysis of 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.

The study was carried out by constructing Monte Carlo micro-simulation model 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.

Following are the outcomes of the study:

• C-section rates (35.9 vs. 13.9 percent)


• Maternal complications, such as preeclampsia and uterine rupture (21.2 vs. 16.5 percent)


• Stillbirths (0.13 vs. 0 percent)


• Newborn deaths (0.25 vs. 0.12 percent)


• Severe neonatal complications, such as respiratory distress and shoulder dystocia (12.1 vs. 9.4 percent)

"Safely preventing primary cesarean deliveries, stillbirths and reducing other perinatal complications are of the greatest concern," said principal investigator Lockwood "Sometimes clinicians do something because that is the way it's always been done. These findings demonstrate the importance of strong evidence-based research in informing and shaping standards of care."

The study authors conclude they recognize not all women nor their providers desire elective inductions and recommend patients have the final say on the timing and mode of delivery. Lead author Rachel Sinkey, MD, notes more study is needed to address health care system logistics and associated costs. Dr. Sinkey conducted the research when she was a maternal-fetal medicine fellow at USF Health and is now an assistant professor of obstetrics and gynecology in the Division of Maternal-Fetal Medicine, University of Alabama at Birmingham.

Mathematical 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.

For more information click on the link: https://doi.org/10.1371/journal.pone.0193169