Chocolate consumption in pregnancy and reduced likelihood of preeclampsia.

Background: Preeclampsia is a major pregnancy complication with cardiovascular manifestations. Recent studies suggest that chocolate consumption may benefit cardiovascular health.
Methods: We studied the association of chocolate consumption with risk of preeclampsia in a prospective cohort study of 2291 pregnant women who delivered a singleton livebirth between September 1996 and January 2000. Chocolate consumption was measured by self report in the first and third trimesters, and by umbilical cord serum concentrations of theobromine, the major methylxanthine component of chocolate. Preeclampsia was assessed by detailed medical record review for 1943 of the women. We derived adjusted odds ratios (aOR) and 95% confidence intervals (CIs) from logistic regression models controlling for potential confounders.
Results: Preeclampsia developed in 3.7% (n = 63) of 1681 women. Cord serum theobromine concentrations were negatively associated with preeclampsia (aOR = 0.31; CI = 0.11-0.87 for highest compared with lowest quartile). Self-reported chocolate consumption estimates also were inversely associated with preeclampsia. Compared with women consuming under 1 serving of chocolate weekly, women consuming 5+ servings per week had decreased risk: aOR = 0.81 with consumption in the first 3 months of pregnancy (CI = 0.37-1.79) and 0.60 in the last 3 months (0.30-1.24).
Conclusions: Our results suggest that chocolate consumption during pregnancy may lower risk of preeclampsia. However, reverse causality may also contribute to these findings.