Maternal Midpregnancy Plasma trans 18:1 Fatty Acid Concentrations Are Positively Associated with Risk of Maternal Vascular Complications and Child Low Birth Weight.

Background: Evidence is plentiful that trans fatty acids (TFAs) induce vascular inflammation with adverse metabolic consequences. However, it is not clear whether TFAs increase the risk of vascular pregnancy complications such as preeclampsia.Objective: We investigated associations between midpregnancy maternal plasma trans 18:1 fatty acid (t18:1) concentrations and pregnancy course and outcomes.Methods: Participants were 6695 pregnant women and newborns from the Generation R Study, Rotterdam, Netherlands (enrollment in 2001-2005). Maternal midpregnancy (mean ± SD gestational age: 20.7 ± 1.2 wk) t18:1 plasma concentrations were determined and related to gestational age and sex-adjusted birth weight SD scores, placental weight, and the risk of preeclampsia. In addition, we explored potential time trends by testing the association of maternal plasma t18:1 concentrations with birth weight in birth cohorts given the Dutch industry-initiative to lower food TFA contents during the inclusion period. Multiple logistic and linear regression analyses were performed, taking various socioeconomic and biological covariates into account.Results: A higher midpregnancy maternal plasma t18:1 concentration was associated with lower birth weight (SD score, adjusted β: -0.10; 95% CI: -0.15, -0.04; P < 0.001) and placental weight (kilograms, adjusted β: -10,65; 95% CI: -20.23, -1.07; P = 0.03) and with a higher risk of preeclampsia (adjusted OR: 1.65; 95% CI: 1.10, 2.49; P = 0.02). We observed a 31% decrease in the median plasma t18:1 concentration in our population over time, but the association between the plasma t18:1 concentration standardized per birth year and birth weight was comparable between birth-year cohorts (years 2001-2005).Conclusions: A higher maternal midpregnancy plasma t18:1 concentration was associated with lower birth weight and placental weight and with a higher risk of preeclampsia. Although the intake of TFAs in our population decreased during the inclusion period, the association with adverse pregnancy outcomes was unchanged even at lower maternal plasma t18:1 concentrations.