Vaginal childbirth and bladder neck mobility.

OBJECTIVE

Hypermobility of the bladder base is a predictor of stress urinary incontinence (SUI) in the female and at least partly due to pregnancy and vaginal childbirth. The purpose of this study was to quantify the effect of vaginal parity and birthweight on anterior compartment relaxation.

DESIGN

Retrospective observational study.

SETTING

Outpatient uroynaecological clinics.

POPULATION

Five hundred and seventy three women seen for primary urogynaecological assessment.

METHODS

Files of patients seen by the first author for assessment and translabial ultrasound imaging at urogynaecological units in Brisbane and Sydney, Australia, were reviewed for routinely-collected obstetric data and imaging results.

MAIN OUTCOME MEASURES

Ultrasound parameters of anterior vaginal wall descent such as urethral rotation on Valsalva manoeuvre, bladder neck position on Valsalva, bladder neck descent and maximal descent of a cystocele on Valsalva.

RESULTS

ANOVA analysis demonstrated a highly significant relationship between vaginal childbirth and bladder neck position on Valsalva (p < 0.001), bladder neck descent (p = 0.002) and maximal descent of a cystocele (p = 0.001). A large part of this effect was seen after one vaginal delivery. There was a trend towards increased bladder neck mobility (p = 0.065) with vaginal operative deliveries. Maximal recorded birthweight did not correlate with parameters of hypermobility.

CONCLUSION

Vaginal childbirth is strongly associated with increased anterior vaginal wall descent, with most of this effect being due to the first vaginal delivery.