Are we preventing the primary cesarean delivery at the second stage of labor following ACOG-SMFM new guidelines? Retrospective cohort study.

Objective: In 2014, the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal Fetal Medicine (SMFM) published an Obstetric Care Consensus for safe prevention of primary cesarean delivery. We aimed to assess whether these guidelines decreased the primary CD rate during the second stage of labor, in our department.

Design, setting, and population: A retrospective cohort study of all women reaching the second stage of labor, at term, in a single university-affiliated medical center between2010 and 2017.

Methods: We compared maternal and neonatal outcomes over three year's periods:-pre-guidelines (2010-2013) vs. 2nd period - post-guidelines (2014-2017).

The main outcome measures: CD rate at 2ndstage of labor.

Results: The study included 11,464 women. The CD rate in the 2nd stage of labor has increased significantly from 4% to 5.9% in the post-guidelines period (OR 1.48, 95% CI 1.16-1.89, p = .001). After a sub-analysis of specific subgroups, and adjustment for confounders, the increase was solely observed in nulliparous women (aOR 1.418, 95% CI 1.067-1.885, p = .016). Furthermore, increased odds for vaginal operative delivery were observed in the multiparous women in the post-guidelines period (2.7% vs. 4.1%, p = .046).

Conclusions: The implementation of the new ACOG and SMFM guidelines was not associated with a change in the CD rate performed at the 2nd stage of labor in the whole study population. However, there was a rise in the CD rate performed at the 2nd stage in nulliparous women. Furthermore, there was an increase in operative deliveries in the whole study population, especially in multiparous women, without an apparent increase in other immediate adverse neonatal or maternal outcomes.