Objective: Physical activity (PA) is hypothesized to reduce the risk of preeclampsia, but few epidemiologic studies have simultaneously evaluated leisure time PA (LTPA), sedentary activity, occupational activity, and non-occupational, non-leisure time PA. Thus, we assessed the independent and combined effects of these different types of PA during pregnancy on preeclampsia and gestational hypertension risk.
Methods: Preeclamptic (n = 258), gestational hypertensive (n = 233), and normotensive (n = 182) women identified from Iowa live birth records (2002-2005) were participants in Study of Pregnancy Hypertension in Iowa. Disease status was verified by medical chart review. All PA exposures were self-reported. Multinomial logistic regression was used to test for associations between various PA types and risk for preeclampsia or gestational hypertension.
Results: After adjusting for prepregnancy BMI, increasing levels of LTPA were associated with a reduced risk of preeclampsia (trend, p = 0.02). Additionally, increasing amount of time spent active each day was associated with decreasing risks for preeclampsia (adjusted, trend; p = 0.03). Increasing amount of time spent sitting per day was associated with an increasing risk of preeclampsia (adjusted, trend; p = 0.10). Women whose activity averaged >8.25 h per day were at a significantly reduced risk of preeclampsia relative to women active <4.2 h per day (adjusted OR 0.58, 95 % CI 0.36, 0.95). Most analyses evaluating the risk of gestational hypertension yielded null results or results that trended in the direction opposite of the preeclampsia results.
Conclusion: Consistent with previous studies, these data suggest increasing PA during pregnancy may reduce preeclampsia risk while increasing levels of sedentary activity may increase disease risk.
Keywords: Gestational hypertension; Occupational activity; Physical activity; Preeclampsia; Pregnancy-induced hypertension.