Fat intake during pregnancy and risk of preeclampsia: a prospective cohort study in Denmark.

BACKGROUND: Previous studies suggest that eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA), may decrease the risk of preeclampsia, but many suffer from important methodological limitations.

METHODS: We prospectively examined the association between fat intake during pregnancy and preeclampsia and among 65,220 singleton pregnancies in the Danish National Birth Cohort (1996-2002). Women were asked to report their diet around gestation week 20 with a food frequency questionnaire. Preeclampsia diagnosis was obtained via linkage with the Danish National Patient Registry. We estimated relative risks (RR) and 95% confidence intervals (95% CI) of preeclampsia and severe preeclampsia according to fat intake using logistic regression models with generalized estimating equations to account for repeated pregnancies per woman while adjusting for potential confounders.

RESULTS: We documented 1302 cases of preeclampsia, including 301 cases of severe preeclampsia. Intake of long-chain omega-3 fatty acids was associated to preeclampsia. Women in the top quintile of DHA intake had a lower risk of preeclampsia (RR 0.67 (0.51-0.89)) and severe preeclampsia (RR 0.46 (0.25-0.83)) than women in the bottom quintile. Women who met daily recommended intake of EPA+DHA according to the Dietary Guidelines for Americans (≥250 mg/day), had a lower risk of severe preeclampsia (RR 0.77 (0.60-0.99)), but not of preeclampsia (RR 0.93 (0.82-1.05)). Conversely, ALA intake was associated with higher risk of severe preeclampsia (RR 1.71 (1.07-2.75)).

CONCLUSIONS: Higher intake of DHA is inversely related to preeclampsia and severe preeclampsia, whereas ALA increases the risk of severe preeclampsia among Danish women.