Cervical length and risk of antepartum hemorrhage in presence of low-lying placenta

Objectives: To evaluate whether transvaginal ultrasound cervical length (TVU CL) can predict antepartum bleeding (APB) in women with low-lying placenta. Study design: A retrospective study was performed including pregnancies with low-lying placenta for which third trimester TVU CL was available. Multiple pregnancies were excluded. Short cervix was defined as TVU CL ≤25mm. Outcomes of interest were compared with respect to the TVU CL. Results: Forty three cases of singleton pregnancies complicated by low-lying placenta in third trimester were identified. Short cervix was reported in 8 cases (19%). APB (75% vs. 31 %, p = 0.02), blood transfusions (25% vs. 3%, p = 0.02), lower birth weight (2246 vs. 2985g, p = 0.02), and neonatal intensive care unit (NICU) admissions (50% vs. 17%, p = 0.04) were more frequent in the women with short cervix. Rate of unplanned cesarean delivery for APB was similar between both the groups (25% vs. 28%, p = 0.83). Conclusions: In women with low-lying placenta persisting into third trimester, short cervical length can be used as a predictor for APB.