Twin versus singleton pregnancy and preterm prelabour rupture of the membranes.

Purpose: The primary purpose of this study was to compare the latency period between preterm prelabour rupture of the membranes (PPROM) and delivery in twin versus singleton pregnancies. The secondary purpose was to compare the neonatal outcome of these two groups. Methods: A retrospective case control study was performed on 33 consecutive bichorionic twin pregnancies with gestational age 20 to 36 weeks admitted to the Antwerp University Hospital with PPROM from 1995 to 2000. These were matched with singletons experiencing PPROM at the same gestational age. Groups were compared for smoking behaviour, whether conception was spontaneous or with artificial reproductive technology, dilation at the moment of PPROM, latency period between PPROM and delivery, the use of tocolytics, antibiotics, corticosteroids, cervicovaginal culture results and neonatal morbidity and mortality. Results: The latency period was significantly shorter in twins (median 19 versus median 47 hours; p = 0.01) and significantly more twins were born within 48 hours after rupture of the membranes (74.2 % versus 51.5 %; p = 0.01). This is due to a difference in the group with gestational age 30 or less weeks, after gestational age 30 weeks no significant difference exists. No other differences were noted between groups. Conclusion: No clinically relevant differences for the perinatal outcome after PPROM in twin versus singletons can be noted, but delivery is more likely to result within 48 hours after PPROM in cases of a twin pregnancy.