Publication:

Midtrimester cervical length as a predictor of labour outcomes: a prospective observational study

Background Preterm birth remains a major contributor to neonatal morbidity and mortality worldwide. Mid-trimester cervical length assessment using transvaginal ultrasound is useful in predicting a spectrum of labour outcomes, including preterm birth, post-dated pregnancy, need for labour induction, and operative delivery.

Methods This hospital-based prospective observational study was conducted at Justice K. S. Hegde Charitable Hospital from June 2023 to November 2024. Mid-trimester cervical length was measured using transvaginal ultrasound between 18 and 24 weeks of gestation in 96 asymptomatic primigravida and second gravida women with singleton pregnancies. Participants were followed until delivery, and labour outcomes were recorded. Statistical analysis was performed using statistical package for the social sciences (SPSS) version 20.0.

Results The mean cervical length was 3.71±0.38 cm. Spontaneous labour occurred in 72.9% of participants, while 27.1% required labour induction. Vaginal delivery occurred in 72.9% and caesarean section in 27.1%. Cervical length showed a statistically significant association with the onset of labour (p=0.012) and mode of delivery (p=0.023), suggesting its potential role as an independent predictor of labour dynamics beyond traditional risk stratification. Shorter cervical lengths were associated with spontaneous labour, whereas longer cervical lengths were linked to labour induction and caesarean delivery.

Conclusions Mid-trimester cervical length measurement by transvaginal ultrasound, even within the normal range, serves as a clinically relevant predictor of labour outcomes. Its integration into routine antenatal assessment may enable more precise risk stratification, improved counselling, and individualized obstetric management, extending its role beyond traditional preterm birth prediction.