Cesarean section: does it really prevent the development of postpartum stress urinary incontinence? A prospective study of 363 women one year after their first delivery.

AIMS: Stress urinary incontinence (SUI) in young women is usually the result of pelvic floor injury during vaginal delivery. Whether cesarean section delivery may prevent such injury is questionable. We undertook a prospective study to compare the prevalence of SUI among primiparae 1 year after spontaneous vaginal delivery versus elective cesarean section, or cesarean section performed for obstructed labor.

METHODS: Three hundred and sixty-three consecutive primiparae were recruited immediately after delivery and were followed for 1 year. Women were asked upon recruitment whether they had ever experienced SUI before pregnancy. Those who had SUI before pregnancy were excluded. Thus, only cases of de novo childbirth-associated SUI were analyzed. Patients were divided into three subgroups according to the mode of delivery: spontaneous vaginal delivery (n = 145), elective cesarean section (n = 118), and cesarean section performed for obstructed labor (n = 100). Patients who underwent elective cesarean section were not given a trial of labor. Cesarean sections for obstructed labor were performed at a mean cervical dilatation of 8.7 +/- 1.6 cm and arrest of 184 +/- 24 min. Prevalence, frequency, and severity of postpartum SUI, as well as demographic and obstetric parameters, were analyzed in each subgroup.

RESULTS: The three subgroups were comparable with respect to maternal age, weight, and height. Prevalence of postpartum SUI was similar after spontaneous vaginal delivery (10.3%) and cesarean section performed for obstructed labor (12%). However, SUI was significantly less common following elective cesarean section with no trial of labor (3.4%, P < 0.05). Approximately half of the symptomatic patients in each subgroup reported either moderate or severe symptoms, however, only 15-18% expressed their desire for further evaluation.

CONCLUSIONS: Prevalence of postpartum SUI is similar following spontaneous vaginal delivery and cesarean section performed for obstructed labor. It is quite possible that pelvic floor injury in such cases is already too extensive to be prevented by surgical intervention. Conversely, elective cesarean section, with no trial of labor, was found to be associated with a significantly lower prevalence of postpartum SUI. Whether the prevention of pelvic floor injury should be an indication for elective cesarean section is yet to be established.