EFFECT OF PREGNANCY ON ANAL-SPHINCTER MORPHOLOGY AND FUNCTION

Twenty pregnant women were investigated prospectively to establish if pregnancy had any effect on the function and morphology of the anal sp hincters. Anal endosonography and manometry were performed during preg nancy and 6 weeks after Caesarean section. Muscle thicknesses of the p uborectalis, longitudinal muscle, internal and external anal sphincter were measured. There was no significant difference in the muscle thic kness of either before and after Caesarean delivery. The maximum resti ng pressure and the maximum squeeze pressure were not significantly ch anged. No significant correlation was found between anal pressure and muscle thickness of either sphincter. Pregnancy itself does not have a significant effect on anal sphincter morphology or function. Any chan ges in sphincter function that occur in relation to pregnancy or deliv ery are likely to be due to mechanical trauma rather than hormonal cha nges in pregnancy.