Physical Activity in Pregnancy: Improving Health for Two Generations
We are excited to see the 2019 Canadian Physical Activity Guidelines in Pregnancy1 released. These guidelines represent a “foundational shift” in how we view exercise in the prenatal period. They strengthen the recommendation that most women can safely exercise throughout pregnancy, and also position prenatal physical activity as a therapy that can “reduce pregnancy complications and optimize health across the lifespan of two generations” (https://bjsm.bmj.com/content/52/21/1339 ).
Family physicians, care for women before, during, and after pregnancy. This provides a unique perspective from which to see how pregnancy health and future health are linked. Adverse pregnancy outcomes such as gestational diabetes (GDM) and hypertensive disorders of pregnancy (HDP) have increased over past decades. These outcomes are associated with an increased risk of developing cardiovascular disease (CVD)2. CVD is the number one killer of Canadian women and intervening early to impact future health is fundamental to family medicine. Moderate intensity prenatal exercise (600 MET-min/week which = 140 minutes brisk walking, or resistance exercise ) results in a 25% reduction in the odds of developing GDM or HDP.
If the impact on GDM and HDP isn’t impressive enough, additional benefits of 150 minutes a week of moderate intensity exercise include reduced rates of antenatal depression and anxiety, decreased caesarian section and instrumental deliveries, decreased urinary incontinence, decreased lumbopelvic pain, and decreased total gestational weight gain. Moderate intensity exercise in pregnancy is not associated with increased rates of miscarriage, preterm birth, stillbirth, neonatal death, preterm/pre-labour rupture of membranes, neonatal hypoglycemia, birth defects, or low birth weight. It is important to recognize that currently, less than 15% of women meet the recommendation for 150 min/week of moderate activity throughout pregnancy.4As benefits were seen with less frequent and intense exercise, pregnant women should be encouraged to be active at any level.1
While more physical activity is associated with greater health benefits, no safe upper limit was established based on existing research. Women who wish to exercise at high intensity or train for competition should seek the advice of their obstetrical care provider. 1
There are absolute contraindications to moderate intensity exercise, including ruptured membranes, premature labour, unexplained persistent vaginal bleeding, pre-eclampsia, placenta previa after 28 weeks, incompetent cervix, intrauterine growth restriction, higher order multiples (e.g. triplets) uncontrolled type 1 diabetes, uncontrolled hypertension, uncontrolled thyroid disease, and other serious cardiovascular and respiratory diseases.
There are general safety precautions to consider when counselling on physical activity in pregnancy. Scuba diving is not safe in pregnancy as the fetus is not protected from decompression sickness and gas embolism. It is recommended women avoid sporting activities with physical contact or risk of falling (e.g. downhill skiing) which may increase risk of fetal trauma. The Physical Activity Readiness Medical Examination for Pregnancy (PARmed-X for Pregnancy) is a tool developed by CSEP and endorsed by SOGC and Health Canada for healthcare providers, exercise professionals, and pregnant women (https://vancouver.ca/files/cov/par-q-plus-form-for-pregnancy-before-exercising.pdf ).
Pregnancy is an important opportunity for family physicians to improve the health of two generations of Canadians!
Dr. Karen Fleming
Dr. Milena Forte
References:
1. Mottola MF, Davenport MH, Ruchat S, et al 2019 Canadian guideline for physical activity throughout pregnancy. Br J Sports Med 2018;52:1339-1346.
2. Coutinho, T., Lamai, O., & Nerenberg, K. (2018). Hypertensive Disorders of Pregnancy and Cardiovascular Diseases: Current Knowledge and Future Directions. Curr. Treat. Options Cardiovasc. Med., 20(7), 56.
3. Davenport MH, Ruchat S-M, Poitras VJ, et al. Prenatal exercise for the prevention of gestational diabetes mellitus and hypertensive disorders of pregnancy: a systematic review and meta-analysis. Br J Sports Med 2018;52:1367–75.
4. Evenson KR , Wen F. Prevalence and correlates of objectively measured physical activity and sedentary behavior among US pregnant women. Prev Med 2011;53(1-2):39–43.doi:10.1016/j.ypmed.2011.04.014
