Effect of the length of the second stage of labor on pelvic floor dysfunction

Pelvic floor dysfunction refers to any combination of incontinence, overactive bladder, pelvic organ prolapse, and sexual dysfunction. Pelvic floor dysfunction affects approximately 25% to 30% of women and is linked to parity and age. Some obstetrical risk factors have been highlighted, though the second stage of labor has not been as thoroughly investigated. Allowing a longer second stage has been suggested as a method of reducing the rates of cesarean delivery in nulliparous women, though it has also been linked to pelvic floor injuries.

This study aimed to determine the effect of the length of the second stage of labor on self-reported pelvic floor dysfunction.

This was a single-center prospective cohort study in a tertiary referral obstetrical unit. Nulliparous women attending routine antenatal clinics were recruited to complete the Australian Pelvic Floor Questionnaire during pregnancy and again 3 months after delivery. The primary outcome in this study was the effect of the length of the second stage of labor on total pelvic floor scores when analyzed using multiple regression. The models were adjusted for the mother's age, mother's body mass index, length of the second stage of labor, fetal birthweight, mode of delivery, and perineal trauma. The secondary outcomes included the comparison of maternal, obstetrical, and functional pelvic floor outcomes based on the mode of delivery and the length of the second stage of labor.

Among the 295 women who were recruited, the length of the second stage of labor and body mass index were associated with self-reported bladder dysfunction on multiple regression, whereas maternal age was protective. Compared with those with 60 to 120 minutes or <60 minutes of second stage of labor, women with that longer than 120 minutes had higher rates of stress incontinence (85.7% [>120 minutes] vs 41.7% [60-120 minutes] or 52.5% [<60 minutes], P=.001), urinary urgency (89.3% [>120 minutes] vs 39.6% [60-120 minutes] or 53.8% [<60 minutes], P<.001), and fecal incontinence (10.7% [>120 minutes] vs 0% [60-120 minutes] or 1.2% [<60 minutes], P=.027). There were no differences in the rates of sexual activity or dyspareunia. Women delivering vaginally had higher rates of stress incontinence (57.6% vs 38.0%, P=.006) than those undergoing cesarean delivery, though there were no differences in other pelvic floor symptoms or pelvic floor scores.

A prolonged second stage of labor is associated with more self-reported bladder dysfunction at 3 months postnatal in primiparous women. Women with a longer second stage of labor should be informed about the risk of short-term bladder dysfunction, though the prevalence of long-term sequelae is unknown.