Does episiotomy protect against injury of the levator ani muscle in normal vaginal delivery?

AIMS: To investigate whether episiotomy is associated with avulsion of the levator ani in its pubic insertion after normal vaginal delivery.

METHODS

This is an observational study at a tertiary obstetric unit recruited 194 primiparous women who had normal vaginal delivery with or without episiotomy. All women underwent translabial 4D ultrasound scanning after delivery. Tomographic ultrasound imaging was used to diagnose levator avulsion. Lesions were recorded as unilateral or bilateral. The investigators were blinded to all clinical data. The influence of other variables associated with delivery such as maternal age, body mass index, gestational age, birth weight, fetal head circumference, and use of epidural anesthesia was recorded and their relation with avulsion was also studied.

RESULTS

Avulsion was identified in eleven (10.9%) of the 101 women with episiotomy and in fourteen (15.1%) of the 93 women without. The difference was not statistically significant (P = 0.401). Other variables showed no influence on the prevalence of avulsion.

CONCLUSIONS

Episiotomy does not appear to be associated with injury to the levator ani muscle in its pubic insertion in normal vaginal delivery.