Obstetric management of a woman's first delivery and the implications for pelvic floor surgery in later life

Objective To determine the influence of intrapartum care during a first delivery on the risk of pelvic floor surgery in later life. Design Nested case-control study with record linkage of a historical cohort and a current morbidity database. Setting Hospital births in Dundee 1952-1966. Population The 7556 primiparous women from the Walker cohort. Methods The cases (n= 352) were women who delivered a first singleton baby at term (>= 37 weeks) and subsequently had pelvic floor surgery. Controls (n= 1403) were women who delivered their first baby during the same time period and did not undergo surgery. Univariate and multivariate logistic regression analyses were performed taking account of demographic, anthropometric and obstetric factors. Main outcome measure Pelvic floor surgery. Results Caesarean section was associated with a reduced risk of pelvic floor surgery compared with spontaneous vaginal delivery (odds ratio 0.16, 95% CI 0.05-0.55). Forceps delivery and infant birthweight > 4.0 kg were not identified as significant risk factors (OR 0.94, 95% CI 0.71, 1.25, and OR 0.94, 95% CI 0.50, 1.75, respectively). Episiotomy and prolonged labour (> 12 hours) may be associated risk factors but were of borderline significance (OR 1.46, 95% CI 0.99, 2.10, and OR 1.51, 95% CI 1.00, 2.27). Conclusion Caesarean section in a first pregnancy appears to protect against pelvic floor surgery in later life.