Regular exercisers have stronger pelvic floor muscles than nonregular exercisers at midpregnancy

Today all healthy pregnant women are encouraged to be physically active throughout pregnancy, with recommendations to participate in at least 30 minutes of aerobic activity on most days of the week in addition to performing strength training of the major muscle groups 2-3 days per week and also pelvic floor muscle training. There is, however, an ongoing debate whether general physical activity enhances or declines pelvic floor muscle function.

The objectives of the study were to compare vaginal resting pressure, pelvic floor muscle strength, and endurance in regular exercisers (exercise ≥30 minutes 3 or more times per week) and nonexercisers at midpregnancy. Furthermore, another objective was to assess whether regular general exercise or pelvic floor muscle strength was associated with urinary incontinence.

This was a cross-sectional study at mean gestational week 20.9 (±1.4) including 218 nulliparous pregnant women, with a mean age of 28.6 years (range, 19-40 years) and prepregnancy body mass index of 23.9 kg/m² (SD, 4.0). Vaginal resting pressure, pelvic floor muscle strength, and pelvic floor muscle endurance were measured by a high-precision pressure transducer connected to a vaginal balloon. The International Consultation on Incontinence Questionnaire Urinary Incontinence Short Form was used to assess urinary incontinence. Differences between groups were analyzed using an independent-sample Student t test. Linear regression analysis was conducted to adjust for prepregnancy body mass index, age, smoking during pregnancy, and regular pelvic floor muscle training during pregnancy. The significance value was set to P ≤ .05.

Regular exercisers had statistically significant stronger (mean 6.4 cm H₂O [95% confidence interval, 1.7-11.2]) and more enduring (mean 39.9 cm H₂Osec [95% confidence interval, 42.2-75.7]) pelvic floor muscles. Only pelvic floor muscle strength remained statistically significant, when adjusting for possible confounders. Pelvic floor muscle strength and not regular general exercise was associated with urinary continence (adjusted B, -6.4 [95% confidence interval, -11.5 to -1.4]).

Regular exercisers at midpregnancy have stronger pelvic floor muscles than their sedentary counterparts. However, pelvic floor muscle strength and not regular general exercise was associated with urinary incontinence. There is a need for additional studies in elite athletes and women performing more strenuous exercise regimens.