Objectives: To assess the prevalence of urinary symptoms, the relationship between urinary symptoms and vaginal descent, and the association between urinary symptoms and obstetric factors.
Study design: Five hundred and thirty-seven women were interviewed and underwent a urogynaecological evaluation 3 months after vaginal delivery. Quantitative-type variables were subjected to Student's t test. Simple logistic regression analyses were carried out on the symptoms studied as a function of risk factors.
Results: 8.2% of primiparae showed stress urinary incontinence and multiparae in 20% (P=0.0001); urge incontinence was present in 5.5% of primiparae and in 13% of multiparae (P=0.004). Significant correlations were found among operative vaginal delivery, dysuria (P=0.048) and frequency (P=0.036). Urinary incontinence appeared associated with induced labour with prostaglandins (P=0.018) and with general maternal factors, such as parity (P=0.001) and elevated weight at the beginning of pregnancy (P=0.019).
Conclusions: It is likely that the pathogenesis of postpartum urinary incontinence includes not only the effects of pelvic floor trauma on urethrovesical mobility under stress, but also a deficiency in urethral resistance caused by drugs, such as prostaglandins.