Persistent urinary incontinence and delivery mode history: a six-year longitudinal study

OBJECTIVE: To investigate the prevalence of persistent and long term postpartum urinary incontinence and associations with mode of first and subsequent delivery. DESIGN: Longitudinal study. SETTING: Maternity units in Aberdeen (Scotland), Birmingham (England) and Dunedin (New Zealand). POPULATION: Women (4214) who returned postal questionnaires three months and six years after the index birth. METHODS: Symptom data were obtained from both questionnaires and obstetric data from case-notes for the index birth and the second questionnaire for subsequent births. Logistic regression investigated the independent effects of mode of first delivery and delivery mode history. MAIN OUTCOME MEASURES: Urinary incontinence-persistent (at three months and six years after index birth) and long term (at six years after index birth). RESULTS: The prevalence of persistent urinary incontinence was 24%. Delivering exclusively by caesarean section was associated with both less persistent (OR=0.46, 95% CI 0.32-0.68) and long term urinary incontinence (OR=0.50, 95% CI 0.40-0.63). Caesarean section birth in addition to vaginal delivery, however, was not associated with significantly less persistent incontinence (OR 0.93, 95% CI 0.67-1.29). There were no significant associations between persistent or long term urinary incontinence and forceps or vacuum extraction delivery. Other significantly associated factors were increasing number of births and older maternal age. CONCLUSIONS: The risk of persistent and long term urinary incontinence is significantly lower following caesarean section deliveries but not if there is another vaginal birth. Even when delivering exclusively by caesarean section, the prevalence of persistent symptoms (14%) is still high.