It has become almost standard practice to induce mothers who reach 39 weeks gestation. The reasoning is that experts believed it could reduce the risk of cesarean and complications during birth. New evidence from the University of Michigan Health Von Voigtlander Women’s Hospital suggests this may not be entirely true.
“We collaborated with peer hospitals to better understand how labor induction may influence cesarean birth outcomes in real world maternity units outside of a clinical trial,” said the lead author of the study, Elizabeth Langen, M.D., a high-risk maternal-fetal medicine physician. “In our study sample, we found inducing labor in this population of women and birthing people did not reduce their risk of cesarean birth.”
Their study, published in the American Journal of Perinatology, examined 14,135 births from the year 2020. It followed the framework of a previous study known as ARRIVE (A Randomized Trial of Induction Versus Expectant Management).
“We designed an analytic framework mirroring the previous trial’s protocol using retrospective data, but our results didn’t reinforce a link between elective induced labor in late pregnancy and a reduction in caesarian births,” said senior author and U-M professor of nursing Lisa Kane Low, Ph.D., C.N.M., a midwife and researcher at Michigan Medicine and the U-M School of Nursing.
The Michigan study’s findings directly contradicted the findings in the ARRIVE study; women were actually more likely to need a cesarean if they had an elective induction at 39 weeks (30 percent compared to 24 percent). Mothers who underwent expectant management were also less likely to experience other complications, such as postpartum hemorrhaging (8 percent versus 10 percent), hypertension (6 percent versus 9 percent), and operative vaginal delivery (9 percent versus 11 percent).
Researchers say there are several reasons the results may have been so contradictory. The Michigan participants underwent pre-screening and a thorough consent process with trained study team members. In the ARRIVE trial, 72 percent of the women declined participation. This suggests women who participated may have felt more pressured to undergo induction, which may have affected the outcome results.
“Better outcomes may have occurred in the trial because the participants were fully accepting of this process,” Low said. “Further research is needed to identify best practices to support people undergoing labor induction,” she added. “Prior to initiating an elective induction of labor policy, clinicians should also ensure resources and a process to fully support shared decision-making.”
Michigan study authors also found that induction practices may not have been applied equally across all demographic groups, which could have had an impact on results.
“These findings suggest that the practice of elective induction of labor may not be equitably applied across birthing people,” Langen said. “We can only speculate about the reasons for these differences, but it’s important that we pursue equitable application of evidence-based practices for all who would benefit.”
Location may not be as big of a factor, however, as the Michigan study examined birth results from hospitals of various sizes, all across the state.
“Inductions of labor for both medical indications and individual preferences will continue to be part of modern obstetrics, making it important to pursue strategies that optimize the induction process and outcomes,” Langen said. “Future work should include a health equity approach and include the voices of pregnant people and their experiences of changes in care management.”
