OP19.06: Longitudinal changes of subpubic arch angle during pregnancy

To assess the longitudinal changes of the subpubic arch angle (SPA) during the three trimesters of pregnancy. A group of 78 women was enrolled in the first trimester pregnancy. Each woman was assessed three times during pregnancy (I, II and III trimester), measuring SPA using a recently described highly reproducible 3D transperineal ultrasound (linear reconstruction with contrast enhancement technique). Repeated measures analysis of variance (rANOVA) was used to study SPA changes during pregnancy. Among the 78 women recruited, 43 women were nulliparous while 35 were multiparous. 58/78 (74.4%) women had a vaginal delivery, while 20 (25.6%) women delivered by Caesarean section. SPA mean (±SD) was 121.2±9.1, 123.2±80.8, and 125.1±8.23 in the first, second, and 3rd trimester, respectively. SPA changes were statistically significant (F = 31.808, P < 0.0005), although was small. Post hoc tests using the Bonferroni correction revealed a significant progressive increase of SPA from 1st to 2nd, and from 2nd to 3rd trimester. Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.