Transvaginal ultrasound cervical length for prediction of spontaneous labour at term: a systematic review and meta-analysis.

Abstract

The possibility to predict the delivery date is a question frequently raised by pregnant women. However, a clinician has currently little to predict when a woman at term will deliver. To evaluate the predictive accuracy of transvaginal ultrasound (TVU) cervical length (CL) for spontaneous onset of labour in singleton gestation enrolled at term by a meta-analysis. We performed a literature search in electronic databases. We included only studies assessing the accuracy of TVU CL in prediction of spontaneous onset of labour in singleton gestations with vertex presentation who were enrolled at term. The primary outcome was the accuracy of CL for prediction of spontaneous labour within 7days. Pooled sensitivities and specificities were calculated. Five studies including 735 singleton gestations were included. For the prediction of spontaneous labour within 7days for CL <30mm the pooled sensitivity was 64% and pooled specificity was 60%. The higher the CL, the better the sensitivity; the lower the CL, the better the specificity. A woman with a singleton gestation at term and a TVU CL of 30mm has a <50% chance of delivering within 7days, while one with a TVU CL of 10mm has an over 85% chance of delivery within 7days. TVU CL at term has moderate value in predicting the onset of spontaneous labour. A woman with a TVU CL of 10mm or less has a high chance of delivering within a week. Cervical length at term has moderate value in predicting the onset of spontaneous labour.