Effect of vaginal delivery on anal morphology revealed by anal endosonography

ABSTRACT

This study included 37 women [mean age of 29.8 years ranged 23-40 years], 20 of them were parous and 17 were nulliparous. For all women, anal endosonography was performed using Kretz Combison 311. Anal canal structures were measured at three levels; high, mid and low. Of the 20 parous women, three had anterior external sphincter defects and 17 had no endosonographic evidence of an anal canal sphincter scar and these women were compared with 17 nulliparous ones. A full set of endosonographic measurements was obtained. There was no significant difference between parous and nulliparous women with respect to subepithelial or internal sphincter thickness at any level. The longitudinal muscle was significantly thicker at both proximal and mid canal levels. Distal anal canal external sphincter was significantly greater in parous women when compared with the nulliparous ones. The anterior ring was significantly thinner in parous women when compared with nulliparous ones. It appeared that vaginal delivery caused change in anal canal anatomy