Hypertensive disorders of pregnancy are a major cause of maternal and fetal morbidity & mortality. Complications include growth restriction, oligohydramnios, placental abruption, preterm birth and perinatal death, as well as longer-term metabolic and cardiovascular morbidity. Pre-eclampsia and hypertension of pregnancy are risk factors for future development of cardiovascular disease (1).
Moderate to high quality evidence from RCTs reported that physical activity-only interventions were associated with a 39% reduction in odds of developing hypertension of pregnancy (22 RCTs, n=5316), and a 41% reduction in odds of developing pre-eclampsia (15 RCTs, n=3322) (2). Pregnant women needed to accumulate at least 600 MET-min/week of moderate intensity activity in order to achieve >25% reduction in odds of hypertension of pregnancy or pre-eclampsia. Regression analyses showed that benefits would be achieved with physical activity frequency at least 3 days/week or at least 25 minutes/session. Combined physical activity and co-interventions (usually counselling about diet/physical activity, with unsupervised physical activity) were less effective than physical activity interventions alone. However compliance was low and previous work has demonstrated that supervision is important for the effectiveness of a physical activity intervention. This is in agreement with other work reporting that diet and physical activity interventions can decrease hypertension of pregnancy (RR 0.30 to 0.66, low to very low-quality evidence) (3). Women of normal weight (BMI 18.5-25kg/m2) randomised to an aerobic exercise intervention (35-90 minutes, 3-4x/week, starting before 23/40) had significantly lower incidence of hypertensive disorders (1.0% vs 5.6%, RR 0.21, 95%CI 0.09-0.45; n=2059) compared with controls (4).
Aerobic exercise in singleton pregnancy (30-60 minutes, 2-7x/week, compared to a more sedentary population) is associated with significantly reduced risk of hypertensive disorders of pregnancy overall (5.9% vs 8.5%, relative risk 0.70, 95%CI 0.53 to 0.83, 7 studies, n=2517), and specifically with significantly reduced risk of hypertension of pregnancy (2.5% vs 4.6%, relative risk 0.54, 95%CI 0.40 to 0.74, 16 studies, n=4641) (5). A Cochrane review reported reduced incidence of maternal hypertension in women exposed to diet and/or physical activity interventions, compared to controls (11 studies, n=5162, average RR 0.70, 95%CI 0.51 to 0.96, low quality evidence) (6). However, neither of these reviews demonstrated a significant effect on incidence of pre-eclampsia.
A smaller review of RCTs of physical activity-only interventions in obese/overweight women (5 studies, n=671) did not demonstrate a significant difference in either hypertension of pregnancy (RR=0.63, 95%CI 0.38 to 1.05, p=0.08) or risk of pre-eclampsia (RR=1.39, 95%CI 0.66 to 2.93, p=0.38) (7). When dietary interventions are included, low-quality evidence suggests a reduction in hypertension in overweight and obese pregnant women (RR 0.30 to 0.66) (3).
Quality of evidence
Strength of Recommendation
Physical activity and exercise interventions during pregnancy are associated with decreased chance of hypertensive disorders including hypertension of pregnancy and preeclampsia.
1. Mosca L et al. Effectiveness-based guidelines for the prevention of cardiovascular disease in women-2011 update: Guidelines from the American heart association Circulation 2011;123:1243-62
2. 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;52:1367-1375
3. Farpour-Lambert NJ et al. Obesity and weight gain in pregnancy and postpartum: an evidence reviewof lifestyle interventions to inform maternal and child health policies Front Endocrinol (Lausanne) 2018;9:546
4. Di Mascio D et al. Exercise during pregnancy in normal-weight women and risk of preterm birth: a systematic review and meta-analysis of randomised controlled trials Am J Obstet Gynecol 2016 Nov;215(5):561-571
5. Magro-Malosso ER et al. Exercise during pregnancy and risk of gestational hypertensive disorders: a systematic review and meta-analysis Acta Obstet Gynecol Scand 2017;96:921-931
6. Muktabhant B et al. Diet or exercise, or both, for preventing excessive weight gain in pregnancy Cochrane Database Syst Rev. 2015 Jun 15;(6):CD007145
7. Du MC et al. Effects of physical exercise during pregnancy on maternal and infant outcomes in overweight and obese pregnant women: A meta-analysis Birth 2018 Sep 21