Prenatal exercise cuts preeclampsia risk by 34%: During first 20 weeks of pregnancy. (Obstetrics).

NEW ORLEANS -- Women who are physically active during the first 20 weeks of pregnancy have a markedly reduced risk of preeclampsia, according to the results of a new study.

In a case-control study that included 201 women with proteinuric pregnancy-induced hypertension and 383 normotensive women who acted as controls, those who participated in any form of recreational physical activity in the first 20 weeks of pregnancy had a 34% lower risk of pregnancy-induced hypertension, compared with inactive women.

Women who engaged in vigorous activities during pregnancy had a 54% lower risk than controls, Dr. Tanya K. Sorensen reported during a poster session at the annual meeting of the Society for Maternal-Fetal Medicine.

Participating women filled out a questionnaire during their postpartum hospital stay, reporting on the types of recreational activities they had engaged in during early pregnancy, as well as the frequency and average time spent in these activities, said Dr. Sorenson of the perinatal studies center at Swedish Medical Center, Seattle.

The investigators queried the study participants about the distances they walked and their walking pace, as well as about their stair climbing activity.

The women also were asked to report on their typical exercise habits during the year before conception.

Among the women who developed preeclampsia, 49.3% reported no physical activity during pregnancy, compared with 39.2% of those women who remained normotensive.