Cervical Length and Risk of Hemorrhage in Pregnancies with Placenta Previa

Aim: To find out the relationship between ultrasonographic cervical length and risk of antepartum hemorrhage, preterm delivery and emergency caesarean section in pregnancies with placenta previa.

Material and Methods: We performed transvaginal cervical-length measurements on all singleton gestations with placenta previa admitted in our hospital at or beyond 24 weeks of gestation over a span of one year. A complete follow-up of pregnancy was obtained in all cases till delivery and a retrospective chart review was then performed for these cases to investigate the relationship between cervical length and maternal and neonatal outcome.

Results: Overall 70 patients comprised the study, in whom placenta previa persisted till delivery. Cervical length measurement was 30 mm in 43 (61.4%) cases. Cervical length ranged from 20 to 50 mm with a mean of 35.6±0.90 mm. Majority of subjects (51.9%) in whom measurements were done between 28-32 weeks had cervical length 30 mm. The association between gestational age and cervical length was statistically significant.

Conclusion: In pregnancies with placenta previa, a third-trimester transvaginal sonographic cervical length of 30 mm or less is associated with increased risk for hemorrhage, emergency caesarean section and preterm birth.