Recreational Exercise Before and During Pregnancy in Relation to Plasma C-Reactive Protein Concentrations in Pregnant Women.

Background: Pregnant women who are physically active have a lower risk of preeclampsia and gestational diabetes than women who are less active. One possible mechanism is a reduction in low-grade inflammation, as measured by plasma concentrations of C-reactive protein (CRP). The association between exercise and CRP in pregnant women, however, has not been adequately investigated.

Methods: A total of 537 pregnant women, enrolled around the 17th week of gestation in the Norwegian Mother and Child Cohort Study in 2003 to 2004, were studied. Self-reported recreational exercise was recalled for both 3 months before pregnancy and early pregnancy. The total energy expenditure from recreational exercise (total recreational exercise, metabolic equivalent of task [MET]-hr/week) was estimated, and low-, moderate- and vigorous-intensity exercise was defined. Plasma CRP concentrations were measured during pregnancy.

Results: In adjusted linear regression models, mean CRP concentration was 1.0% lower [95% CI = -1.9% to 0.2%] with each 1 MET-hr/week of total recreational exercise before pregnancy. In addition, vigorous-intensity exercise before pregnancy was more strongly related to a reduction in CRP levels than low- or moderate-intensity exercise. However, we observed no association between recreational exercise during pregnancy and plasma CRP levels.

Conclusions: Recreational exercise before pregnancy, especially vigorous exercise, may reduce the risk of maternal inflammation during pregnancy.