RESUMO
INTRODUCTION AND HYPOTHESIS: The aim of the study was to evaluate the association of avulsion and postnatal hiatal dimensions with delivery mode. These anatomical changes on pelvic floor muscle may be assessed by 3-4D ultrasonography. METHODS: This is a prospective observational study that included 164 women: 20 nulliparous, 20 primigravid, and 124 postpartum women (62 at 1 month, 62 at 9 months postpartum). We performed an introital 3-4D ultrasonography to assess levator ani muscle's integrity, levator hiatal area at rest, on Valsalva, and on contraction. RESULTS: Levator ani avulsion was diagnosed in 59.5% of forceps deliveries. There were no statistically significant differences in postnatal hiatal dimensions between normal vaginal deliveries at 9 months postpartum and nulligravid. Levator hiatal area was significantly higher after forceps delivery. CONCLUSION: Low incidence of levator avulsion takes place in normal vaginal deliveries. However, forceps delivery is the riskiest type of delivery for pelvic floor pathology and its recovery.
