Recreational physical activity during pregnancy and risk of preeclampsia.

The potential benefits and risks of physical activity before and during pregnancy are not well studied. We studied the relation between recreational physical activity and the risk of preeclampsia in a case-control study of 201 preeclamptic and 383 normotensive pregnant women. Participants provided information about the type, intensity, frequency, and duration of physical activity performed during the first 20 weeks of pregnancy and during the year before pregnancy. Women who engaged in any regular physical activity during early pregnancy, compared with inactive women, experienced a 35% reduced risk of preeclampsia (odds ratio, 0.65; 95% confidence interval [CI], 0.43 to 0.99). Compared with inactive women, those engaged in light or moderate activities (ie, activities with metabolic-equivalent scores <6) experienced a 24% reduced risk of preeclampsia (95% CI, 0.48 to 1.20). The corresponding reduction for women participating in vigorous activities (metabolic equivalent scores > or =6) was 54% (95% CI, 0.27 to 0.79). Brisk walking (average walking pace > or =3 mi/h), when compared with no walking at all, was associated with a 30% to 33% reduction in preeclampsia risk. Stair climbing was inversely associated with the risk of preeclampsia (P for trend=0.039). Recreational physical activity performed during the year before pregnancy was associated with similar reductions in preeclampsia risk. These data suggest that regular physical activity, particularly when performed during the year before pregnancy and during early pregnancy, is associated with a reduced risk of preeclampsia.