Abstract

The uterocervical angle (UCA) has recently been studied as a parameter to identify women at risk for spontaneous preterm birth (PTB). Objective: This study aimed to investigate the distribution of UCA values by transvaginal sonography (TVS) at gestational age (GA) 16 - 24 weeks of singleton pregnancy. Study design: TVS was performed in 1.039 singleton pregnancies, viable fetuses at gestational age (GA) 16 - 24 weeks, at the Department of Pregnancy Management & Prenatal Diagnosis, Hai Phong Obstetric and Gynecology Hospital from September 2019 to June 2020. The UCA distribution by GA was visualized using a scatter plot. The range of UCA values and their relationship with GA were assessed using quantile regression analysis. P < 0.05 was considered statistically significant. Results: The normal range of UCA (5th and 95th percentiles) was from 46.99 degrees (95% CI: 35.45o - 44.31o) to 125.38 degrees (95% CI: 128.92o - 139.32o) with significant changes during this GA period (2.0 degrees per week, p < 0.001). Conclusion: The value of the UCA increases significantly with gestational age from 16 - 24 weeks, so it is advisable to monitor and evaluate the UCA, especially in pregnant women at high risk for PTB.