(590) Labor Progression in Women with or without Premature Rupture of Membranes

To compare labor progression in women with premature rupture of membranes (PROM) versus those without PROM.

Study Design:

Retrospective study conducted at a tertiary university medical center between July 2012 and September 2020. Women carrying singleton pregnancies who underwent vaginal delivery at or beyond 37 weeks of gestation were included. Exclusion criteria included multiple gestations, non-vertex presentations, and cesarean deliveries. The cohort was divided into two groups: PROM and No-PROM. Interval-censored regression estimated median labor duration at each centimeter of cervical dilatation. Multivariate analyses adjusted for maternal age, chronic hypertension, thrombophilia, and gestational age were conducted.

Results:

26,438 women were included, with 6,626 (25.1%) in the PROM group and 19,812 (74.9%) in the No-PROM group. In primiparous women, first stage of labor (3-10cm) was significantly shorter in the PROM compared to the No PROM group, with medians of 5.00 (95^th percentile 12.79) versus 5.48 hours (95^th percentile 13.91; P< 0.001). Similarly, in multiparous women, the median times were 2.70 (95^th percentile 8.68) versus 3.16 hours (95^th percentile 10.06; P< 0.001). The active phase (6-10 cm) did not significantly differ in primiparous women with medians of 2.76 (95^th percentile 8.53) versus 2.84 hours (95th percentile 9.01; P=0.394). However, multiparous women with PROM had a shorter active phase with medians of 1.02 (95^th percentile 4.16) versus 1.16 hours (95^th percentile 4.82; P=0.002).

Conclusion:

Labor progression from 3 cm to full dilatation was significantly shorter in women with PROM compared to those without PROM, regardless of parity. Active phase duration was statistically significantly shorter in multiparous women with PROM, albeit the median difference of 8 minutes is not clinically significant.