Prolonged Preterm Premature Rupture fo the Membranes: A Risk Factor For Development Of Abruptio Placentae ✓The association between prolonged preterm premature rupture of the membranes and abruptio placenta was investigated in a case-control study. The incidence of abruptio placentae in the 13.042 pregnant women between the 01.01.1989 to 31.12.1990 was 1.12%. The incidence of abruptio placentae among 264 women with singleton pregnancies who had ruptured membranes for at least 24 hours was 6.81%, significantly higher than the 1.88% observed among the 265 randomly systemacit selected controls with preterm rupture of the membranes (Ki-Kare= 71.940; p