A comparison of the predictive value of transvaginal cervical length at 11–14 weeks and at 18–22 weeks of gestation in preterm labour

Preterm labor is the major cause of preterm birth that affects 12–18% of all births in India. Cervical shortening or effacement is one of the first steps in the parturition process. In the present study the mean cervical length at 11-14weeks for the term delivered group is 4.04+-0.35cms and the mean cervical length for the preterm delivered group 3.85±0.33 cms. The cervical length at 18–22 weeks was significantly shorter in the group that had preterm deliveries (2.77 cms) than in those who had term deliveries (3.74 cms) (P < 0.001). The cervical length at 18–22 weeks in the group that delivered preterm was significantly shorter than in those who had delivered at term. The mean cervical length showed a gradual decrease from the first to the second scan and an increased risk for preterm delivery was seen in those cases which demonstrated a rapid shortening in cervical length.