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 who were randomized to either be induced around 39 weeks or to be left alone (referred to as expectant management). The results literally 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. This topic was the focus of numerous follow-on studies at the recent Society for Maternal-Fetal Medicine annual meeting. Three hot topics of discussion were a) what is the impact on the cost of care, b) how would near-universal induction of labor impact the function of obstetric units, and c) can the results of a study conducted in sophisticated clinical-trial-ready hospitals be generalized to the approximately 3,000 American hospitals where babies are born.
Addressing the cost question, the same researchers presented data demonstrating that although women whose labor was induced spent approximately 50 percent longer on labor and delivery than women who weren’t induced, those who were left alone were evaluated in their doctors’ offices and also in the hospital, had more tests performed before delivery than women who were induced. This makes sense, of course: if you’re not pregnant any more, there’s no reason to see your obstetrician for a pregnancy-related issue. In dollars, however, a different group of researchers estimated that the cost of this policy would be an additional $2.6B annually in the United States.
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 pharmacologic treatment to get the cervix ready for labor - a process that can take may hours or even days. 68 percent of women induced in this study required this treatment. 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, or modify the way women are cared for. 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 optimizes their schedule - whether it’s getting to the office, or getting home at night. (One study demonstrated the association between delivery timing and time of day, exposing the impact of these subtle, non-medical influences on care.)
Lastly, there are societal questions about what it means to consider pregnancy as an experience that generally ends with a scheduled induction of labor, and how that impacts women’s experience and agency.
This blog appeared on the Center for Health Journalism blog here.