Based on current guidelines, pregnant women are encouraged to stay physically active throughout pregnancy, including aerobic activity and strength training of major muscle groups. After pregnancy, exercises that strengthen and maintain good physical health is recommended to be resumed gradually and as soon as medically safe (1). There have been concerns that starting with regular physical activity at an early stage postpartum may harm the already stretched and weak muscles and connective tissue of the pelvic floor (2). To date there is scant knowledge on how exercise training may impact on the pelvic floor muscles (PFM) and prevalence of pelvic floor dysfunction after childbirth (3). The aims of the present study were to investigate whether regular exercise training six weeks postpartum negatively influence vaginal resting pressure (VRP), PFM strength and PFM endurance and prevalence of stress urinary incontinence (SUI), pelvic organ prolapse (POP) and anal incontinence (AI) in primiparous women 12 months postpartum.

This cross-sectional study included 167 primiparous women at 12 months postpartum, mean age 28.7 (SD 4.3), mean body mass index (BMI) 24.7 (SD 4.3). Electronic questionnaires were used for information on background characteristics, exercise training and prevalence of SUI, POP and AI. Manometer was used for measurement of PFM variables. Exposure was exercise training including brisk walking, bicycling, running, skiing, swimming, ballgames, fitness centres, low-impact aerobic classes, high-impact aerobic classes, postpartum fitness classes, dancing, horseback riding and others. The weekly frequency score was summed across all exercises except strolling into regular exercisers as those exercising ≥3 times ≥30 min/week within six weeks postpartum and non-exercisers as those “never exercising” and “strolling”. Primary outcomes were VRP, PFM strength and PFM endurance measured by a high-precision pressure transducer connected to a vaginal balloon. Before the measurement, all participating women were given a short anatomy lecture and taught how to correctly contract the PFM using observation and vaginal palpation. Secondary outcomes were symptoms of SUI, POP and AI assessed by the International Consultation on Incontinence Modular Questionnaire (ICIQ). Differences between exercisers and non-exercisers were assessed using Independent sample t-test and Chi-square test. Two women reported AI 12 months postpartum, so no further analysis was done on this condition. Multiple linear regression and logistic regression were used to assess the influence of exercise training six weeks postpartum on VRP, PFM strength and PFM endurance, SUI and POP 12 months postpartum. The following covariates were assessed at 12 months postpartum and used as independent variables: age, strenuous manual work, BMI, pelvic floor muscle training and prolonged second stage of labour >120 minutes. In the regression model for SUI, SUI at mid-pregnancy was included as an additional independent variable and for POP, symptoms of POP at mid-pregnancy was included. Significance level was ≤0.05. There was no specific power calculation in relation to exercise training.

Seventy out of 167 (41.9%) women were exercising ≥3 times ≥30 min/week within six weeks postpartum. Of those, eight (4.8%) women reported doing high-impact exercises (including jumping and running). No difference was found for PFM variables, symptoms of SUI or POP between the eight women conducting high-impact exercises compared to those doing low-impact exercise. In the total study population of 167 women no significant difference between regular exercisers (n=70) and non-exercisers (n=97) on PFM variables (Table 1), SUI 18 (25.7%) versus 29 (29.9%) (OR 0.35, 95% CI: 0.41, 1.62, p-value 0.55) or POP symptoms 11 (15.7%) versus 22 (22.7%) (OR 1.23, 95% CI: 0.29, 1.42, p-value 0.27) were found. In the adjusted model associations with SUI at 12 months were: SUI at mid-pregnancy (OR=16.46, 95%CI: 2.62, 15.85, p-value <0.001) and BMI >30 OR=4.59, 95%CI: 1.11, 11.30, p-value=0.03). BMI between 25-29.9 was borderline associated with increased risk of SUI at 12 months postpartum (OR=3.96, 95%CI: 1.02, 7.34, p-value=0.05). Associations with POP at 12 months were POP at mid-pregnancy (OR=10.16, 95%CI: 1.87, 13.83, p-value=0.001).

The present study did not show any negative effect of low-impact exercise starting within 6 weeks postpartum on the pelvic floor. Although the participants can be classified as fulfilling the recommendations of regular exercise, the results cannot be generalized to more strenuous exercisers and elite athletes performing exercise with repetitive jumping and bouncing or heavy weightlifting early postpartum (2). Although no difference was found between the eight women performing high-impact exercise and those performing low-impact exercise, we can´t rule out a difference between the groups if the numbers of strenuous exercisers were higher. More research on high impact exercisers and heavy weightlifting is warranted.

Regular low-impact exercise training ≥3 times ≥30 min/week starting within 6 weeks postpartum does not seem to harm the pelvic floor, or to affect the presence of symptoms of SUI and POP at 12 months postpartum. Hence, based on the results from this study, health personnel and coaches can recommend regular low-impact physical exercise in the early postpartum period.

The American College of Obstetricians and Gynecologists ACOG Committee opinion no. 650. Summary: physical activity and exercise during pregnancy and the postpartum period. Obstet Gynecol 2015;126:1326-7.
Bo K,Artal R,Barakat R,Brown WJ,Davies GAL,Dooley M,Evenson KR,Haakstad LAH,Kayser B,Kinnunen TI,Larsen K,Mottola MF,Nygaard I,van Poppel M,Stuge B,Khan KM,Commission IOCM. Exercise and pregnancy in recreational and elite athletes: 2016/17 evidence summary from the IOC Expert Group Meeting, Lausanne. Part 3-exercise in the postpartum period. Br J Sports Med 2017;51:1516-25.
Nygaard I,Shaw JM. Physical activity and the pelvic floor. Am J Obstet Gynecol 2016;214:164-71.