[EVALUATION OF INCIDENCE OF POSTPARTUM OCCULT ANAL SPHINCTER INJURIES BY ENDOANAL ULTRASONOGRAPHY.]

The estimated overall risk of intrapartum damage of the anal sphincter (IUAS) is 1% of all vaginal births. The so called "occult" anal sphincter injuries (defects of the anal sphincter established by endoanal ultrasonography - OASIS) occur in 33% of primiparous women after vaginal birth. The most logical explanation for OASIS is that they are either completely missed or detected, but not mentioned in the patient's documentation, or erroneously classified as a low grade tear. Objectives To es7ablish the actual values of OASIS in the study population using endoanal ultrasonography. Material and methods The study included 29 vaginal deliveries in Porodnisnica Ljubljana in the January to June 2009 period, and 34 patients from July 2009 to May 2010, who gave birth in ObsTetric Clinic of the University Hospital - Pleven. Results The identified UAS frequency in our dtudy (25.4%) confirms the results of the incidence of such damage, cited in the literature. Discussion The results vary extensively from reported frequency of anal sphincter injuries among researched population, reflecting underesTimation of the problem, diagnostic gaps and inadequate clinical management behavior and tracking patients.