Pre-pregnancy physical activity and preeclampsia risk: a prospective population-based cohort study

Objective. To test the hypothesis that women physically active prior to pregnancy are at reduced risk of preeclampsia. Design. Population-based prospective cohort study. Setting. Linkage between the HUNT-1 Study (health study) and the Medical Birth Registry of Norway. Population. Women with singleton live births after participation in the HUNT-1 Study were included, if the newborn's gestational age was more than 22 weeks or birthweight above 500 g. Women pregnant during participation in the health study were excluded. Methods. The physical activity level was measured by a questionnaire. Information on the women's coming birth was provided by the Medical Birth Registry of Norway. Odds ratios of preeclampsia were calculated and adjusted for maternal age, parity, smoking and body mass index. Main outcome measure. Preeclampsia. Results. Of 3,656 women included, 167 (4.6%) developed preeclampsia. Overall, we found no link between pre-pregnancy physical activity and preeclampsia. Only among the women physically active for 120 min/week or more, a tendency for reduced risk was found (adjusted odds ratio 0.6:95% CI 0.3-1.2). Conclusion. Women physically active prior to pregnancy were not at reduced risk of developing preeclampsia.