Cervical length and risk of antepartum bleeding in women with complete placenta previa

Objective To evaluate if cervical length predicts prepartum bleeding and emergency Cesarean section in cases of placenta previa. Methods Between September 2005 and September 2007, cervical length was measured by transvaginal ultrasound in women with complete placenta previa persisting into the third trimester ofpregnancy. A complete follow-up of pregnancy was obtained in all cases. Results Overall, 59 women were included in the study group. The mean ± SD gestational age at ultrasound was 30.7 ± 2.7 weeks and the cervical length was 36.9 ± 8.8 mm. Cesarean delivery was performed in all cases, at a mean gestational age of 34.7 ± 2.3 weeks. Twenty-nine (49.1%) of the women presented prepartum bleeding and 12 (20.3%) required an emergency Cesarean section prior to 34 completed weeks due to massive hemorrhage. Cervical length did not differ significantly between cases with and those without prepartum bleeding (35.3 ± 9.3mmvs. 38.4 ± 8.2 mm; P = 0.18), but was significantly shorter among patients who underwent emergency Cesarean section < 34 weeks due to massive hemorrhage compared with patients who underwent elective Cesarean section (29.4 ± 5.7 mm vs. 38.8 ± 8.5 mm; P = 0.0006). Conclusions Transvaginal sonographic cervical length predicts the risk of emergency Cesarean section < 34 weeks in women with complete placenta previa.