Labor induction vs expectant management in women over 35
Results from a randomized clinical trial evaluating a variety of maternal and neonatal outcomes showed that for primigravid women ages 35 and older with an uncomplicated pregnancy, labor induction near term neither afforded benefits nor increased risks compared with expectant management.1
Conducted in the United Kingdom, the multicenter study enrolled 619 women who had a singleton live fetus in a cephalic presentation with no known congenital abnormality and no contraindications to labor, vaginal delivery, or expectant management. Women were randomized to labor induction or expectant management after stratification by maternal age (35 to 37 years, 38 to 39 years, ≥40 years).
Cesarean delivery was analyzed as the primary outcome, and the rate did not differ significantly comparing the labor induction and expectant management groups (32% vs 33%; relative risk, 0.99; 95% confidence interval, 0.87 to 1.14].
In addition, there were no statistically significant differences between the labor induction and expectant management groups in any secondary endpoints.
“Although our study was not designed or powered to assess the effects of labor induction on stillbirth, based on the outcomes analyzed, labor induction at 39 weeks remains a reasonable choice for older women who are worried about late stillbirth,” said James Thornton, MD, professor of obstetrics and gynaecology, University of Nottingham, UK.
“However, labor induction did not prove to reduce any adverse outcomes. Furthermore, we cannot be certain there are no long-term effects on the baby because we do not yet have data from follow-up after discharge. Therefore, women who so desire should feel free to await spontaneous labor.”
In developing the study, the investigators noted that there is a small but definite increased risk of antepartum stillbirth at term among women ages 35 years and older relative to their younger counterparts. However, labor induction is associated with increased rate of cesarean delivery and other risks.
In addition, the proportion of women who are becoming pregnant at age 35 and older has been steadily increasing in the Western world, but there is no evidence basis for counseling them about the choice between labor induction and expectant management. Previous research comparing these 2 strategies in women of advanced maternal age either focused on a population with complicated pregnancy or were small studies dating back to the 1970s.