Balancing harm and benefit for induction of labor at 41 weeks: Slow acting is the problem

Abstract

We thank Seijmonsbergen-Schermers et al.¹ for their interest in and comments on our paper from 2023 in AOGS.² We acknowledge their observation about overestimating perinatal death risk with expectant management at 41 weeks of gestational age, as we pointed out in the discussion section of our article.² In the Dutch perinatal registry, there is no information on the date and time of the antepartum death and no information on a possible planned induction date. Therefore, we made an informed choice about dealing with the inability to distinguish between antepartum and peripartum death for expectant management when IUFD is first detected after spontaneous labor had started, as was reported.² Obviously, we support that information from studies on induction at 41 weeks, like for instance,^{3, 4} and our study,² should be included in systematic reviews to make the evidence more accessible to health care providers and pregnant women.

In obstetrics, weighing the value of possible gain and associated loss in advance is a difficult task for pregnant women and their caregivers, and a gestational age of 41 weeks is only a weak predictor of harm. ‘Gain and loss’ differ between nulliparous and parous women, and between countries like Sweden and the Netherlands, where induction takes place in the hospital and home delivery is part of a perinatal care system for spontaneous labor in healthy pregnant women.

Whether a certain number needed to treat or harm (NNT/NNH) is an important factor for a woman to choose for induction is a matter of debate. The range for NNT to prevent perinatal death in uncomplicated pregnancy at 41 weeks will indeed be somewhere between 326 and 1830, or slightly higher. From a clinical perspective, an NNT exceeding 300 may reasonably justify recommending labor induction. However, in the context of shared decision-making, it remains essential to explore the woman's values, preferences, ensuring that the decision aligns with her personal circumstances and informed choice. Nevertheless, an individual woman can decide that the increased risk due to an emergency cesarean section or an intensive care admission of her newborn, and the inability to deliver at home, weighs more for her, that she may choose to decline induction even when the NNT is below 300.

Decreasing the NNT by continuously implementing new RCTs to determine who really benefits from induction of labor, monitoring outcomes of daily care, and developing proper information strategies for patients and, not least, minimizing harm through training of professionals, are all essential parts of this goal. It took the INDEX study 10 years to finalize a paper on the basic question of whether induction of labor at 41 weeks is beneficial in the Netherlands alone.⁵ Given the annual cohort of 29,000 pregnant women in the Netherlands having this dilemma, this issue could have been solved within 1 year. No new RCT studies are foreseen. The fundamental problem is the inadequate progress. We are too slow in minimizing NNT, which results in too much unnecessary and preventable harm.

Joris A. M. van der Post wrote the first draft, all authors reviewed and edited the letter and approved the final version.