Should pregnant women be induced? The conventional wisdom is challenged

Published on
May 14, 2019

To induce labor, or not.

For as long as physicians can remember, it has been a truism that inductions of labor lead to an increased risk of cesarean delivery. This was part of teaching in medical school and residency, it was enshrined in clinical guidelines from the American College of Obstetricians and Gynecologists (ACOG), and it became part of contemporary lore: If you don’t want a cesarean, avoid an induction of labor.

But there were flaws in the logic of the studies that established this truism, so the largest American obstetric research network studied over 6,000 first-time moms. They were randomized to either be induced around 39 weeks or left alone (referred to as “expectant management”). The results turned decades of teaching on its head: There was no difference in newborn outcomes, but women who were induced were about 16 percent less likely to deliver by cesarean than women who were left alone. 

Obstetricians, and particularly the policy-making bodies including ACOG, are now wrestling with the implications of that study, which was published in August in The New England Journal of Medicine. This topic was the focus of numerous follow-on studies at the recent Society for Maternal-Fetal Medicine annual meeting in Las Vegas. Three hot topics of discussion were 1) what is the impact on the cost of care, 2) how would near-universal induction of labor impact the function of obstetric units, and 3) can the results of a study conducted in sophisticated academic research hospitals be generalized to the approximately 3,000 American hospitals where babies are born. 

Addressing the cost question, the same researchers who did the original study presented data demonstrating that women whose labor was induced spent approximately 50 percent longer on labor and delivery than women who weren’t induced. Also, the induced group was evaluated less often in their doctors’ offices as well as in the hospital, and had fewer tests performed before delivery than women who were left alone. This makes sense, of course: Induced women deliver sooner, so they have less time during pregnancy to be evaluated and accumulate visits and tests. In dollars, however, a different group of researchers estimated that the cost of inducing all mothers at 39 weeks would increase annual spending on pregnancy in the United States by $2.6 billion dollars – even after taking into account savings related to fewer cesareans.

The big unknown is how this research translates into the real-world practice of obstetrics in the United States. My concern is that when these practices are implemented in the small and mid-sized hospitals that are the staple of American obstetrics, the results will be different.

Induction of labor, particularly for first-time moms, typically begins with administering drugs to get the cervix ready for labor, a process that can take may hours or even days. According to the New England study, 68 percent of women induced required this treatment to ready the cervix for labor. It’s unclear that hospitals have the beds or nurses necessary to induce more and more women. 

Many academic medical centers of the type that conducted this study are staffed by physicians who are dedicated to laboring women around the clock. In this context, there is little pressure or incentive to accelerate labor, change course and deliver by cesarean. In contrast, many community physicians are simultaneously seeing patients in their office while caring for laboring women, and are subtly incentivized to direct the care of their patients in a way that’s convenient for their schedule — whether it’s getting to the office, or getting home at night. (One study demonstrated the association between delivery timing and shift change times — subtle, non-medical considerations can strongly influence care.) Will community-based physicians be able to adapt to the more time-intensive practice of inducing most births without resorting to delivery in an operating room? I have my doubts.

Lastly, there are societal questions about what it means to consider pregnancy as an experience that generally ends with a scheduled induction of labor. What would it mean for women’s experience of birth and agency?

For all these reasons, I think doctors need to be cautious about overturning decades of practice and inducing at 39 weeks as a standard practice.