Abstract

Introduction:This study aimed to evaluate the association between sonographic markers including anterior and posterior uterocervical angles (UCA) in the first and second trimester and the mean difference of UCA measured in the first and second trimester with the occurrence of the spontaneous preterm birth (PTB) in the pregnant women.

Methods:Ultrasonographic measurements of the angle among the anterior and posterior inferior uterine segment and the cervix were done in singleton pregnancies in gestational age (GA) of 13 and 14 weeks and repeated in 28th weeks of gestation. Participants were followed until delivery and GAs were documented.

Results: Among 216 pregnant women, 31 participants had PTB. The mean of anterior and posterior UCA in the PTB group was more than term group, significantly; at the same trimester (0.001>p). The mean difference between first and second trimester anterior UCA was greater in the PTB group (7.0±4.2vs4.7±1.6, p=0.008). The cut-off value according to ROC analysis in predicting PTB for anterior UCA at the first trimester was 95.5º and for the second trimester was 105.5º. Cut-off values for Posterior UCA at first and second trimester were 96.5º and 104.5º, respectively. The Pearson analysis revealed a significant negative relationship between anterior and posterior UCA at first and second trimesters and gestational age at birth.

Conclusion:Anterior and posterior UCAs measured in the first and the second trimester has the potential to serve as predicting markers for the sPTB. Between the aforementioned markers, anterior UCA when is measured in the second trimester is more valuable (the best AUC for sPTB).