No association between delivery mode and rectal prolapse: evidence from a nationwide cohort
Bjarne Melvås, Rode Grönkvist, Erika Gyllencreutz, Teresia Svanvik, Jennifer Park, Hanna de la Croix, Charlotta LarssonAbstract
Introduction
The primary aim was the risk of being diagnosed with rectal prolapse following exclusively vaginal versus exclusively caesarean delivery. Secondary aims were prevalence of rectal prolapse after delivery over time and associated risk factors.
Methods
This study included all women in the Swedish Medical Birth Registry (MBR) between 1973–2020 with exclusively vaginal or caesarean deliveries. Two age-matched control groups of nulliparous women and men drawn from the total population registry were included for comparison. The primary outcome was diagnosis of rectal prolapse, obtained from the Swedish National Patient Register. Hazard ratios were estimated using Cox proportional hazards models adjusted for age, income, education, nicotine use, maternal BMI, preeclampsia, infant birthweight, breech presentation, induction of labour and parity. Age and parity were treated as time-varying covariates and missing data were handled using multiple imputation by chained equations. Secondary analyses for obstetric and socioeconomic risk factors and hazard ratios between all four groups were performed using Poisson- and Cox regression.
Results
The study included 2 million individuals (sectio = 241 554 and vaginal = 1 691 775) with 2034 cases (sectio = 219; vaginal = 1815). No significant difference (HR 0.96; P 0.56, c.i. 0.82–1.11) in the risk of rectal prolapse was observed. In the primary model, rectal prolapse was significantly associated with maternal age, parity, induction of labour and socioeconomic factors; however further analyses are required to clarify these associations.
Discussion
Mode of delivery does not appear to influence the risk of rectal prolapse, in contrast to findings for other pelvic floor disorders. Further analyses are ongoing to clarify the role of associated risk factors.