Long-term effects of vacuum extraction on pelvic floor function: a cohort study in primipara

We describe the prevalence of symptomatic pelvic organ prolapse (sPOP), urinary incontinence (UI), fecal incontinence (FI) and obstetric anal sphincter injury (OASI) 20 years after one vacuum extraction (VE) delivery compared with one spontaneous vaginal delivery (SVD) or one acute caesarean section (ACS). We performed a register-based national cohort study of primipara who delivered between 1985 and 1988 and had no further deliveries. Medical Birth Register data were linked to data from postal questionnaires distributed 20 years after the birth (response rate 65.2 %, n = 5 236). Main outcome measures were prevalence and risk factors for pelvic floor disorders (PFDs) and OASI and their impact after VE compared with SVD and ACS. Multivariate logistic regression models were used. The late prevalence of UI, sPOP, and FI was almost identical between VE and SVD. VE almost tripled the rate of OASI compared with SVD (6.3 vs. 2.4 %, p < 0.001). FI rate after an OASI was similar for both VE and SVD [30.2 vs. 27.8 %, adjusted odds ratio (aOR) 1.12; 95 % confidence interval (CI) 0.49-2.56]. Comparing VE without laceration with VE complicated by OASI increased the rate of FI (from 15.4 to 30.2 %, aOR 2.55; 95 % CI 1.26-5.15) and UI (from 39.0 to 61.4 %, aOR 2.28; 95 % CI 1.19-4.34), but the rate of sPOP was almost unaltered (from 15.0 to 15.9 %). VE did not result in additional long-term PFDs provided the rate of OASI was similar to that after SVD. OASI after VE substantially increased the prevalence of FI and UI but did not alter the rate of sPOP.