(1011) Latency antibiotics following previable preterm prelabor rupture of membranes prolongs pregnancy by two weeks

Objective:
Following preterm prelabor rupture of membranes (PPROM), antibiotics have been shown to extend the time between ROM and delivery (latency) as well as improve neonatal outcomes. However, it is unclear whether a similar benefit is seen in pregnancies with previable PPROM. We aimed to ascertain if treatment with antibiotics following previable PPROM prolongs latency to delivery.

Study Design:
Single-center retrospective cohort of pregnancies diagnosed with previable PPROM between 14 0/7 and 21 6/7 weeks between 2012 and 2024. Those who underwent termination, had major fetal anomalies, had a contraindication to expectant management, or met criteria for delivery within 48 hours of ROM, were excluded. Administration of antibiotics at any time after ROM was the exposure of interest. The primary outcome was the latency period between ROM and delivery. Secondary maternal and neonatal outcomes were collected. A multivariable linear regression was performed, adjusting for gestational age at ROM and clustering of observations.

Results:
Of the 95 patients that met inclusion criteria, 63 (66.3%) received antibiotics. The latency period to delivery after previable PPROM for patients who received antibiotics after ROM was 38.15 days. This was 14.7 days (SE= 0.98, p= 0.034) longer compared to a latency of 11.62 days for those who did not receive antibiotics. Patients who received antibiotics delivered more frequently ≥ 22 0/7 weeks (80.95% vs. 15.62%, p< 0.005; Fig 1), had lower rates of intrauterine fetal demise (IUFD) (20.63% vs. 65.62%, p<  0.005), and higher rates of neonatal survival to discharge (49.21% vs. 6.25%, p< 0.031) (Table 1).

Conclusion:
Latency antibiotics after previable PPROM prolonged the time to delivery by an average of 14.7 days. Those who received antibiotics delivered more frequently ≥ 22 0/7 weeks, experienced higher neonatal survival to discharge, and had lower incidence of IUFD. Although randomized prospective studies are needed, these  findings highlight the potential benefit of latency antibiotics after previable PPROM and support their consideration in expectant management.