Material and Method: A retrospective cohort study was conducted on twin and singleton pregnancies that delivered at Rajavithi Hospital, Tertiary public hospital, Bangkok, Thailand between January 1, 2008 and July 31, 2012. Singleton pregnancies as a control group were matched with twin pregnancies based on date of delivery, with a ratio of 1:1. The main outcome of measure was the prevalence of preterm rupture of membranes.

Results: The prevalence of PROM among twin pregnancies had a tendency to be lower than that in singleton pregnancies, 5.4% vs. 9%, but the difference was not statistically significant (p = 0.053). The mean gestational age at delivery for twin pregnancies was significantly lower than singleton, 34.8±3.1 weeks vs. 38.1±2.1 weeks (p<0.001). The rates of cesarean delivery, low birth weight baby, and APGAR scores less than 7 at 5 minutes were also significantly higher in twin pregnancies.

Conclusion: The prevalence of PROM in twin pregnancies had a tendency to be lower than that in singleton, but not statistically significant. The reason may be associated with a high rate of pre-labor cesarean section due to other obstetric complications.

Keywords: Twin pregnancy, Premature rupture of membranes, Obstetrics outcome