With the growing number of resources (and opinions) offering advice about how to relate to the pelvic floor during pregnancy, it's hard to make sense of it all.
Every individual and pregnancy is different, and we recommend an individual assessment with a skilled pelvic floor physical therapist in order to determine what is right for your body. However, we can look to research involving large numbers of pregnant people to see general trends and make recommendations for pregnancy in general.
DOES PELVIC FLOOR MUSCLE EXERCISE IN PREGNANCY PREVENT URINARY INCONTINENCE (UI)?
If you are pregnant, not leaking urine, and doing pelvic floor muscle training, you are 62% less likely to have leaking late in pregnancy and 29% less likely to experience leaking 3 to 6 months postpartum.*
If you are pregnant and already leaking and begin doing pelvic floor muscle training, your risk of leaking in late pregnancy and postpartum is reduced by 26%.*
*This data comes from a 2017 review of 38 studies including 9,892 women by Woodley et al.
HOW SHOULD SOMEONE PRACTICE PELVIC FLOOR EXERCISE IN PREGNANCY?
A randomized controlled trial of 169 first-time pregnant women had the experimental group participate in an exercise class three times per week for 22 weeks. The exercise class included generalized exercise, but also specific cueing for pelvic floor muscle contractions as a separate exercise (not included in the generalized movements such as squats). The results showed that 95.2% of the exercise group never experienced UI in the pregnancy, versus 60.7% of the control group (Pelaez 2014).
Based on our understanding of exercise physiology and how to prescribe exercise, performing strengthening exercise three times per week is a "minimum dose" of exercise to be able to see improvement in strength and function over time.
There is some debate about whether performing pelvic floor exercise can be taught effectively in a group exercise class. Research seems to indicate that once a person has a session of individual instruction, they are able to effectively exercise the pelvic floor in a group setting. We know that over 30% of individuals are unable to contract the pelvic floor correctly without instruction, and 25% actually strain (push down) instead of contracting/lifting the pelvic floor muscles (Benvenuti 1987, Bo 1988, Hesse 1990, Bump 1991).
Based on this information, we recommend at least one session of individual instruction including direct pelvic floor muscle testing to achieve the best results from fitness classes of any kind, especially in pregnancy or postpartum.
DOES PELVIC FLOOR MUSCLE EXERCISE IN PREGNANCY AFFECT CHILDBIRTH OUTCOMES?
A 2015 review of 12 studies of 2243 women in their first pregnancy found that pelvic floor muscle training shortened the first stage of labor by 28 minutes and second stage by 10 minutes. It did not increase the risk of episiotomy, instrumental vaginal delivery, or perineal laceration in first time deliveries (Du 2015).
Benvenuti F, Caputo GM, Bandinelli S, Mayer F, Biagini C, Sommavilla A. Reeducative treatment of female genuine stress incontinence. Am J Phys Med. 1987 Aug; 66(4):155-68.
Bø K, Larsen S, Oseid S, et al. Knowledge about and ability to correct pelvic floor muscle exercises in women with urinary stress incontinence. Neurourol Urodyn. 1988;7:261–262.
Bump R, Hurt WG, Fantl JA, Wyman JF. Assessment of Kegel exercise performance after brief verbal instruction. Am J Obstet Gynecol. 1991;165:322–329.
Du Y, Xu L, Ding L, Wang Y, Wang Z. The effect of antenatal pelvic floor muscle training on labor and delivery outcomes: a systematic review with meta-analysis. Int Urogynecol J. 2015 Oct;26(10):1415-27. doi: 10.1007/s00192-015-2654-4. Epub 2015 Feb 25.
Hesse U, Schussler B, Frimberger J, et al. Effectiveness of a three step pelvic floor reeducation in the treatment of stress urinary incontinence: a clinical assessment. Neurourol Urodyn. 1990;9:397–398.
Pelaez M, Gonzalez-Cerron S, Montejo R, Barakat R. Pelvic floor muscle training included in a pregnancy exercise program is effective in primary prevention of urinary incontinence: a randomized controlled trial. Neurourol Urodyn. 2014 Jan;33(1):67-71. doi: 10.1002/nau.22381. Epub 2013 Feb 6.
Woodley SJ, Boyle R, Cody JD, Mørkved S, Hay-Smith EJC. Pelvic floor muscle training for prevention and treatment of urinary and faecal incontinence in antenatal and postnatal women. Cochrane Database Syst Rev. 2017 Dec 22;12:CD007471. doi: 10.1002/14651858.CD007471.pub3.