Urinary incontinence and weight changes during pregnancy and post partum: a pending challenge.

OBJECTIVE: to analyse the association between urinary incontinence and maternal weight, and its variations in pregnancy and post partum.

DESIGN: observational study of a cohort of women from the start of pregnancy until six months post partum.

SETTING: Hospital San Pedro in La Rioja, Spain.

PARTICIPANTS: 402 pregnant women without urinary incontinence at the start of pregnancy.

MEASUREMENTS AND FINDINGS: the dependent variable was urinary incontinence, assessed using the Urogenital Distress Inventory-Short Form questionnaire. The main independent variables were body mass index (BMI) at the first antenatal visit and six months post partum, weight gain during pregnancy, postpartum weight loss, and weight retained from the start of pregnancy to six months post partum. The association between urinary incontinence and the main independent variables was measured using Student's t-test. Three simple logistic regression models were used to assess the strength of this association, one for each of the independent variables that showed a significant association with urinary incontinence (p<0.05), and three multiple regression models that included the possible variable effect modifiers were also used. At the start of pregnancy, 20.1% of the women were overweight and 8.7% were obese. Six months post partum, 30.3% of the women were overweight and 11.4% were obese. The mean (±standard deviation) retained weight was 2 (±3.1) kg. Postpartum urinary incontinence was associated with BMI at six months post partum, postpartum weight loss and retained weight at six months post partum (p<0.05). The association of urinary incontinence with these variables was significant, and remained stable in both simple and multiple regression analyses with BMI at six months post partum [odds ratio (OR) 1.09 versus 1.08], weight loss from delivery to six months post partum (OR 0.88 versus 0.88), and retained weight from the beginning of pregnancy until six months post partum (OR 1.23 versus 1.19).

KEY CONCLUSIONS: high BMI and weight retention at six months post partum increase the risk of urinary incontinence, whereas postpartum weight loss decreases the risk of urinary incontinence, even if other urinary incontinence risk factors co-exist.

IMPLICATIONS FOR PRACTICE: primary care midwifes can make a major contribution towards the prevention and rehabilitation of urinary incontinence in women. It is important for the midwife and the woman to keep in contact in the first six months post partum. Individualised advice about eating and exercise habits to avoid weight retention after pregnancy may have a considerable impact on decreasing the risk of urinary incontinence.