The Prevalence of Pelvic Floor Hematoma After Vaginal Delivery.

Objective: The goal of this study was to evaluate differences in levator ani hematoma formation within 3 days of delivery between adult women after their first vaginal delivery and adult women who have had multiple vaginal deliveries.

Methods: This was a cross-sectional study at a single institution from 2013 to 2015 using a high-resolution endovaginal ultrasound transducer to identify postvaginal delivery hematoma formation. Logistic regression was used to examine the association between hematoma formation and vaginal parity while considering potential confounders including induction, vaginal operative delivery, vaginal birth after cesarean, fetal weight, fetal head circumference, race and ethnicity, body mass index, age at delivery, gestational age, and length of second-stage labor.

Results: Ninety women (46 vaginal-primiparous; 44 vaginal-multiparous) were included in this study. After adjusting for oxytocin use, length of second-stage labor, and body mass index, the odds of pelvic floor hematoma of 1000 mm3 or greater were 2.93 (95% confidence interval, 0.78-10.91) times greater in women after their first vaginal delivery compared with women with a history of multiple vaginal deliveries. The adjusted odds of pelvic floor hematoma of 1500 mm3 or greater were 6.02 (95% confidence interval, 1.09-33.24) times greater in vaginal-primiparous compared with vaginal-multiparous women.

Conclusions: Although the prevalence of pelvic floor hematoma was higher in vaginal-primiparous women than vaginal-multiparous women after vaginal delivery, hematomas were present in both groups. Future prospective studies are needed to evaluate the additive effect of multiple vaginal deliveries on the pelvic floor.