Impact of delivery mode on electromyographic activity of pelvic floor: comparative prospective study

Several studies evidenced the association between pregnancy, mode of delivery and genitourinary symptoms. However, there are still controversies about the role of mode of delivery in the prevention or aggravation of these symptoms. This study aimed to compare the impact of three distinct modes of delivery on pelvic floor muscle contractility.

Seventy-five primiparous women were divided into three groups: (1) vaginal delivery with mediolateral episiotomy (n = 28); (2) elective cesarean section (n = 26); (3) emergency cesarean section (n = 21). All patients underwent vaginal digital examination, grading the muscle contractility from 0 to 5 and surface electromyography (EMG) of the pelvic floor during the last trimester of pregnancy and 45 days after delivery.

There was a significant increase in pelvic floor contractility in the elective cesarean section group, from 2.35 to 2.92 (P = 0.03), when compared to the vaginal delivery and emergency cesarean section groups. Analysis of electromyography data showed a significant reduction in maximum contraction of the pelvic floor after vaginal delivery, from 39.17 to 31.14 µV (P = 0.001), which was not observed in both cesarean section groups.

Vaginal delivery was associated with a decrease in pelvic floor muscle strength and endurance 45 days after delivery when compared to elective cesarean section as well as emergency cesarean section.