Elective Labor Induction Linked to Elevated Risk of Adverse Outcomes
Latin American women with low-risk pregnancies who undergo elective labor induction are at increased risk for adverse maternal and perinatal outcomes, compared with those who experience spontaneous labor, according to an eight-country study.1 Women who opted for labor induction without any medical indication were more likely than those who delivered spontaneously to require drugs to manage postpartum hemorrhage (relative risk ratio, 1.5), be admitted to the intensive care unit (2.9), need anesthesia or pain-relieving medications and procedures during labor (1.6–3.7) and delay the initiation of breast-feeding (1.1–3.1). Women electing labor induction were also more likely than those delivering spontaneously to undergo hysterectomy (5.2), though the researchers note that caution should be exercised when interpreting this finding, given the small number of cases involved.
To determine the frequency of elective labor induction in Latin America, as well as the associations between elective induction and adverse maternal and perinatal outcomes, researchers performed a secondary analysis of cross-sectional data from the 2004–2005 World Health Organization Global Survey on Maternal and Perinatal Health. The data, collected on every delivery over a 2–3 month period, were obtained from the medical records of 120 randomly selected health facilities located in eight randomly chosen Latin American countries. In all, the researchers analyzed 37,444 deliveries among women with low-risk pregnancies between 37 and 40 weeks of gestation. Multiple logistic regression models were run to determine the maternal and other characteristics associated with elective labor induction and to assess the relative risks for adverse outcomes. Characteristics included in the analyses were maternal age, marital status, education, parity and body mass index; gestational age; and facility type.
Out of the 11,077 cases of induced labor, 1,847 (17%) were elective, representing 5% of deliveries among women with low-risk pregnancies. Administration of oxytocin was the most common method used for elective induction (66%), and led to vaginal delivery in 88% of cases; cesarean section was required in 12% of electively induced deliveries. Women who did not have a partner were less likely than those who did to have an elective induction (odds ratio, 0.8), while women giving birth for the first time were more likely to choose to induce labor than those who had had one or more prior deliveries (1.1). In addition, women delivering at a social security or private health facility were more likely to have an elective induction than those delivering at a public facility (2.9 and 1.9, respectively).
Although the cesarean section rate was higher among women who had had an elective induction than among those delivering spontaneously (12% vs. 9%), the risk of cesarean section was only marginally associated with elective labor induction (relative risk ratio, 1.2). Women who had had elective labor induction had elevated odds of needing drugs to manage postpartum hemorrhage (1.5), undergoing hysterectomy (5.2, although only four hysterectomies were performed among those electively induced), being admitted to the intensive care unit (2.9) and needing epidural anesthesia or other pain-relieving medications or procedures during labor (1.6–3.7). In addition, women who had had an elective induction were more likely than those with spontaneous labor to delay breast-feeding by 1–24 hours (1.1), more than 24 hours (1.6) or more than six days (3.1). Other perinatal outcomes, such as Apgar scores, early neonatal death and admission to the neonatal intensive care unit, were not associated with delivery type, suggesting that elective induction did not offer any advantages to the infant.
The researchers note that the rate of elective labor induction in Latin America is similar to that found in developed countries (around 10%). They add that although the highly elevated risk of hysterectomy among electively induced women should be interpreted cautiously, the finding is nonetheless a concern, especially given that the affected women lost their ability to bear children as the result of a medically unnecessary procedure. "Caution should be exercised when inducing labour without any medical indication," they conclude, "since no clear benefits outweigh the associated risk of an adverse maternal outcome."—L. Melhado
1. Guerra GV et al., Elective induction versus spontaneous labour in Latin America, Bulletin of the World Health Organization, 2011, 89(9):657–665.