PROVIDENCE, R.I. – Compared with cesarean birth without labor, undergoing vaginal birth increased the risk of stress incontinence and prolapse in women who were examined 5–10 years after childbirth, Dr. Victoria L. Handa reported.
The risk of all pelvic disorders, including prolapse, was elevated even further in women who had undergone operative vaginal delivery, she said.
“The results suggest no measurable differences in the relative odds of any pelvic floor disorder for women delivering by cesarean section, including those who labored into the second stage. For vaginal birth, the picture is very different,” said Dr. Handa, director of the advanced training program in female pelvic medicine and reconstructive surgery at Johns Hopkins University, Baltimore.
In this longitudinal cohort study based on hospital obstetric records, 8,285 women who had their first child 5–10 years previously were recruited for the study and 1,011 were enrolled. Women were selected if their obstetric history met one of five categories: cesarean without labor (considered the reference group; n = 192), cesarean during active labor (n = 228), cesarean after complete cervical dilation (n = 140), spontaneous vaginal birth (n = 325), and operative vaginal birth (n = 126). Groups were matched for age at first delivery and interval from first delivery, and were similar with respect to parity and smoking status. At enrollment, a validated questionnaire (Epidemiology of Prolapse and Incontinence Questionnaire) was used to assess pelvic floor symptoms, and the women were examined for pelvic organ support using the Pelvic Organ Prolapse Quantification (POP-Q) System.
“One of the strengths of our study is that [obstetric] exposures were verified by chart review with validated outcomes, and there was [anatomical] evidence of prolapse,” Dr. Handa said.
Overall, 11% of the 1,011 women had stress urinary incontinence, 8% had overactive bladder, and 11% had anal incontinence; 3% reported prolapse symptoms, and 7% had prolapse upon examination (Obstet. Gynecol. 2011;118:777–84).
Compared with women who had a cesarean birth before active labor, women who had a vaginal birth (but no operative vaginal births) had almost a threefold increased risk of stress incontinence and symptomatic prolapse. The odds ratio for prolapse was increased more than fivefold.
Women who had undergone operative vaginal birth fared even worse. The adjusted odds of stress incontinence and overactive bladder were more than quadrupled. There was almost an eightfold increased risk of prolapse upon exam.
In her report, Dr. Handa noted that in addition to demonstrating the dramatic increase in pelvic floor disorders in women with a history of at least one operative vaginal birth, the results showed an increase in urinary incontinence after operative delivery – a finding that had not been definitively documented before. For those who had undergone cesarean delivery, the results showed no association between active labor and pelvic floor disorders.
The study was also the first to demonstrate an association between operative vaginal birth and prolapse, even in asymptomatic women. By continuing to monitor these women, Dr. Handa hopes to be able to document the natural history of prolapse over time, especially in those women who were unaware of their condition.
Dr. Handa did not report any relevant financial disclosures.