The Efficacy of Third Trimester Cervical Length Measurement as A Predictor of Ante-Partum Haemorrhage Among Pregnancies Complicated with Placenta Previa

Aim: To estimate whether the cervical length and can be used as a method to predict peripartum complications as antepartum haemorrhage and preterm delivery in cases of complete placenta previa. Methods: Between October 2013 and April 2014, transvaginal measurement of cervical length was done for 30 cases of complete placenta previa identified between 28 weeks and 36 weeks of gestation. This was correlated to the clinical outcome of pregnancy with recordings for the gestational age at time of delivery, occurrence if any complications as antepartum haemorrhage ,blood transfusion, caesarean hysterectomy , preterm delivery and the need for NICU admission and whether the caesarean section was elective or emergency caesarean section was needed before 36 weeks due to massive haemorrhage. Results: Antepartum haemorrhage necessitating emergency cesarean section was observed in 17 patients (56.7%). This was the basis of grouping the patients into two outcome groups: Emergency CS group and elective delivery group. Using receiver-operating characteristic (ROC) curve analysis we found that a cervical length ≤ 33 mm at 28 weeks was predictive of antepartum haemorrhage necessitating emergency caesarean section with a sensitivity of 88.2% and specificity of 61.5% positive predictive value of 75.0% and negative predicative value of 80.0% and accuracy of 76.7%. Area under the curve (AUC) was 0.760. with P-value < 0.01 Conclusion: Short cervical length measurements at cut-off value ≤33mm may predict increased risk of hemorrhage and emergency caesarean section in patients with complete placenta previa.