Cervical length and prediction of preterm delivery

Abstract

To present a summary of the literature and most recent advances in the clinical use of cervical length for the prediction of preterm birth. Cervical length is predictive of preterm birth in all populations studied, including asymptomatic women with prior cone biopsy, mullerian anomalies, or multiple dilation and evacuations. While cervical length remains the most predictive measurement, funneling may add to its predictive value in certain populations. In terms of interventions aimed at preventing preterm birth once a short cervical length has been identified in asymptomatic women, recent data from a meta-analysis of all trials published so far point to the benefit of ultrasound-indicated cerclage in women with both a prior preterm birth and a cervical length less than 25 mm. Other interventions for a short cervical length such as progesterone and indomethacin are promising, but deserve further study before clinical recommendations can be made. In women with symptomatic preterm labor, a recent trial has shown that knowledge of cervical length (and fetal fibronectin) may be beneficial both in terms of time to triage and reduction of preterm birth. Transvaginal ultrasound cervical length used as a screening tool for prediction and prevention of preterm birth can significantly improve the health outcomes of pregnant patients and their babies.