Use of prophylactic antibiotics in women with previable prelabor rupture of membranes.

OBJECTIVE: To measure the effect of prophylactic antibiotics given at time of previable prelabor rupture of membranes (PROM) on latency.

METHODS: Single center, retrospective cohort study of singleton pregnancies with previable (<23 0/7weeks) PROM. Antibiotics were given at clinician discretion. The primary outcome was latency, defined as duration of time between previable PROM and delivery. Secondary outcomes included delivery at ≥ 23weeks, infant survival, and maternal morbidity. Bivariate analysis compared maternal covariates between women who did and did not receive antibiotics. Antibiotic effect on latency was modeled using a Cox proportional hazards ratio.

RESULTS: 213 women with previable PROM were identified; 77 (36%) remained pregnant and thus were included in this analysis. Forty (52%) of 77 received antibiotics. Compared to women who did not receive antibiotics, those who did had PROM at a later median (IQR) estimated gestational age, EGA, (22.2weeks [20.7, 22.5] vs. 19.3weeks [18, 20.7], p < 0.01). Median (IQR) latency was not different between women who did and did not receive antibiotics (2.2 [0.7, 3.9] vs. 1.5 [0.5, 4.6] weeks, p = 0.49). More infants survived to discharge among women who received antibiotics compared to those who did not [17(43%) vs. 3(8%), p < 0.01]. When adjusted for EGA at PROM, antibiotics were associated with longer latency (HR 0.57 [95% CI 0.33, 0.97], p = 0.01). Antibiotic use was not associated with differences in maternal morbidity.

CONCLUSION: After adjusting for EGA at PROM, antibiotic receipt was associated with longer latency. Larger prospective studies are needed to define the utility of prophylactic antibiotics in previable PROM.