Hormonal Influence in Stress Urinary Incontinence During Pregnancy and Postpartum

Hormonal changes have been proposed as an etiological factor of stress urinary incontinence (SUI) during pregnancy. Our main objective was to demonstrate the role of hormones in SUI development during pregnancy and postpartum. A prospective longitudinal study was designed. Primiparous women without previous urinary incontinence symptoms were included. Symptoms and Quality of Life (QoL) Questionnaires, physical examinations, and hormone concentration (progesterone, estradiol, and relaxin) were collected twice during pregnancy and three times during postpartum. Logistic regression models, with Wald's forward variable selection method, were used. Prevalence of SUI was 11% in the first trimester, 50% in the third trimester, and 16.4% at 6 months postpartum. The risk of developing SUI throughout pregnancy is higher in women with higher progesterone concentration in the first trimester (OR 1.38, 95% CI 1.06-1.81, p < 0.05) and it is lower in women with stronger pelvic floor muscles in the first trimester (OR 0.35, 95% CI 0.17-0.72, p < 0.05). When occurred during pregnancy, SUI has a 14-fold higher risk of persistence 6 months after birth. In addition, the severity of these symptoms is also an independent risk factor for SUI persistence at 6 months postpartum (OR 1.41, 95% CI 1.15-1.73, p < 0.05). Quality of Life was affected for pregnant women with SUI symptoms. SUI is a highly prevalent condition during pregnancy, affecting the QoL of women in many areas. Higher concentration of progesterone can play a role in SUI development during pregnancy. The presence and severity of SUI during pregnancy are risk factors for the persistence of symptoms 6 months postpartum. Sustaining an optimal pelvic floor muscle strength could prevent SUI during pregnancy.