Correlation of mid-trimester cervical length in primigravida with preterm labour

Background: Preterm birth is the leading cause of neonatal morbidity and mortality that is not linked to congenital anomalies or chromosomal disorders. Studies have shown that a short cervix is a significant predictor of preterm birth in both singleton and twin pregnancies, with the risk of spontaneous preterm birth rising as cervical length decreases. Methods: It is a prospective, observational, cross-sectional study conducted over a period of 18 months. The sample size was 500. The cervical length was measured using transvaginal ultrasound between 16 to 24 weeks period of gestation. These participants were followed up till delivery and the correlation of mid-trimester cervical length was done with preterm labour. Results: The mean age of patients was 23.8±3.6 (range, 17-37 years). The mean body mass index (BMI) of patients was 22.6±2.7 (range, 17-33). The mean period of gestation at which trans-vaginal ultrasound was done was 19.6±8.34 weeks. The mean cervical length in patients with pre-term deliveries was 2.7±0.54 and in term deliveries was 3.2±0.43 cm, respectively. The difference in cervical length between the two groups was statistically significant (independent t-test, p<0.001). Conclusions: There is an inverse relationship between cervical length measured by transvaginal ultrasound at 16 to 24 weeks of gestation and risk of preterm delivery.