Chorioamnionitis at latent phase more than doubles the risk for cesarean delivery compared to chorioamnionitis at active phase

Purpose: Chorioamnionitis, or intraamniotic infection, is a common condition, carrying an increased risk of intrapartum cesarean delivery (CD). The morbidity related to chorioamnionitis is more common in those undergoing CD, as compared to those with successful vaginal delivery. We aimed to examine the risk factors associated with CD among women with chorioamnionitis. Methods: A retrospective cohort study from a tertiary medical center. We included women at term carrying a singleton gestation with suspected chorioamnionitis undergoing a trial of labor between 2011 and 2019. The primary outcome was the mode of delivery. Results: Data from 1436 women with chorioamnionitis were analyzed; 1288 (89.7%) were nulliparous. Overall, 1064 (74.1%) delivered vaginally, and 372 (25.9%) by CD. The rate of CD was significantly higher in nulliparous as compared to parous parturients (26.9% vs. 16.9%, P = 0.008), and in those with fever onset at latent phase as compared to those in whom fever appeared at active labor (≥ 6 cm) (47.0% vs. 18.1%, P < 0.001). In a multivariate analysis, CD was positively associated with: onset of fever at latent phase (aOR [95% CI] 4.75 (3.54, 6.32), P < 0.001), nulliparity (aOR [95% CI] 3.25 (1.98, 5.34), P < 0.001), maternal age (aOR [95% CI] 1.52 (1.10, 2.09), P = 0.01) and birth weight (aOR [95% CI] 1.23 (1.04, 1.44), P = 0.01). Conclusion: Women with chorioamnionitis had a high rate of CD. Nulliparity and onset of fever prior to active labor were the strongest independent predictors of CD. It remains to be determined whether those deemed at high risk for failed trial of labor, should undergo CD earlier in the course of labor to improve chorioamnionitis-related outcomes.