Assessment of the effect of vaginal delivery and aging on anal sphincter anatomy and function by three-dimensional endoanal ultrasound and anal manometry

The objective of this study was to examine the anal sphincter of women who had vaginal birth and women who have never had birth in order to understand what kind of an influence vaginal delivery and age has on the anatomy and functions of anal sphincter. Our study was conducted on 3 groups. Group 1 consisted of 10 asymptomatic women between the ages of 18-50 who had never been pregnant. Group 2 consisted of 10 asymptomatic women between the ages of 18-50 who had only vaginal delivery. Group 3 consisted of 10 asymptomatic women at the over 50 age who had only vaginal delivery. Anal manometry test and three dimensional endoanal ultrasonography was applied to all groups. No statistically significant difference was found between the resting pressure (RP) and squeeze pressure (SP) values of groups. No statistically significant difference was found between Group 1 and Group 2 in terms of both internal anal sphincter (IAS) and external anal sphincter (EAS) thickness. It was found that internal anal sphincter (IAS) and external anal sphincter (EAS) thickness showed statistical difference between Group (1 – 3) and Group (2 – 3) (p<0.05). According to the results of Spearman correlation analysis conducted between age and anal sphincter thickness in all groups, a positive strong correlation was found between age and IAS and also EAS thickness. In terms of IAS and EAS thicknesses and pressure findings, a positive significant correlation was found between SP and EAS thickness only in Group 3. As a conclusion, it was found that in asymptomatic women who had vaginal delivery, vaginal delivery did not have a significant influence on the anatomic and functional structure of anal sphincter. However, it was found that IAS and EAS thicknesses changed strongly in a positive way in women with aging.