Preterm Premature Rupture of Membranes in Twins: Comparison of Rupture in the Presenting Versus Non-presenting Sac

OBJECTIVE: This study sought to compare the latency from membrane rupture to delivery and subsequent neonatal outcomes in twin gestations complicated by preterm premature rupture of membranes (PPROM) of the presenting versus non-presenting sac. METHODS: This was a retrospective study of twin pregnancies over a 7-year period diagnosed with PPROM between 12 and 37 weeks gestation with a latency period to delivery of >24 hours. The ruptured sac was identified by ultrasound scan. The study compared the latency period from PPROM to delivery and subsequent neonatal morbidity and mortality resulting from rupture of the presenting versus non-presenting sac. Obstetric and neonatal outcomes were evaluated using a matched-cohort subset analysis (Canadian Task Force Classification II-2). RESULTS: During the study period, 77 twin pregnancies diagnosed with PPROM satisfied the inclusion criteria. The mean latency periods from PPROM to delivery were 10.1 days (n = 7) when the presenting sac ruptured and 41.3 days (n = 10) when the non-presenting sac ruptured (P < 0.05). Neonatal death was higher with PPROM of the presenting than the non-presenting sac (21.4% vs. 0%, respectively; P = 0.05). Neonates were more likely to be affected by retinopathy of prematurity (57% vs. 19%; P < 0.05) but less likely to have persistent pulmonary hypertension of the newborn (0% vs. 25%; P < 0.05) when the rupture occurred in the presenting sac. The rates of other neonatal adverse outcomes were similar between the two groups. CONCLUSIONS: In twin gestations there is a longer latency from PPROM to delivery and fewer neonatal complications when rupture occurs in the non-presenting rather than the presenting sac.