Birth trauma: short and long term effects of forceps delivery compared with spontaneous delivery on various pelvic floor parameters

Objective To compare the effects of forceps delivery and spontaneous delive ry on pelvic floor functions in nulliparous women. A longitudinal prospecti ve study with investigations during the first pregnancy, 10 weeks and 10 Design A longitudinal pl months after delivery. Setting Antenatal clinic in a teaching hospital. Population One hundred and seven patients aged 28+/-4 years, divided into t hose with forceps (n = 25) or spontaneous (n = 82) delivery. Methods Investigations with a questionnaire, clinical examination, assessme nt of bladder neck behaviour, urethral sphincter function, intra-vaginal/in tra-anal pressures during pelvic floor contractions. Results The incidence of stress urinary incontinence was similar in both gr oups at 9 weeks (32% vs 21%, P = 0.3) and 10 months (20% vs 15%, P = 0.6) a fter delivery, as was the incidence of faecal incontinence (9 weeks: 8% vs 4%, P = 0.9; 10 months: 4% vs 5%, P = 1) and the decreased sexual response at 10 months (12% vs 18%, P = 0.6). Bladder neck behaviour, urethral sphinc ter function and intra-vaginal and intra-anal pressures were also similar i n the two groups. However, 10 months after delivery, the incidence of a wea k pelvic floor (20% vs 6%, P = 0.05) and the decrease in intra-anal pressur e between the pre- and post-delivery values (-17+/-28 cm H2O vs 3+/-31 cm H 2O, P = 0.04) were significantly greater in the forceps-delivered women. Conclusions Forceps delivery is not responsible for a higher incidence of p elvic floor complaints or greater changes in bladder neck behaviour or uret hral sphincter functions. However, patients with forceps delivery have a si gnificantly greater decrease in intra-anal pressure and a greater incidence of a weak pelvic floor.