[Effect of different delivery modes on the short-term function of the pelvic floor]

To investigate the effect of different delivery modes and related obstetric factors on the short-term function of the pelvic floor.

One hundred and twenty healthy primiparae women were interviewed at 6-8 weeks postpartum, with 72 women in the vaginal delivery group and 48 women in the elective cesarean section group. Questionnaire on stress urinary incontinence and measurement of diastolic and contractive function of the pelvic floor muscles by electromyogram (EMG) were used for the evaluation and comparison.

The prevalence of stress urinary incontinence in the vaginal delivery group and the elective cesarean section group was 21% and 10% (P = 0. 134) ,respectively. The values of the right act, right work, and average work surveyed by EMG in vaginal delivery group were significantly lower than those in cesarean section group (right act, 12.9 +/- 0.8 vs. 17.3 +/- 1.7, P < 0.05; right work, 59 +/- 5 vs. 95 +/- 17, P = 0.02; average work, 78 +/- 5 vs. 109 +/- 15, P < 0.05). Maternal age, body mass index (BMI) before labor, incontinence during pregnancy, neonatal birth weight and longer duration of second stage were risk factors for stress urinary incontinence postpartum. Incision length of episiotomy, duration of the first stage, and BMI before and (or) after pregnancy affected function of pelvic floor muscles markedly.

The prevalence of stress urinary incontinence after different delivery modes is similar. Some obstetric factors have effects on both stress urinary incontinence postpartum and the function of pelvic floor.