First trimester multivitamin/mineral use is associated with reduced risk of pre-eclampsia among overweight and obese women.

The use of pregnancy-specific multivitamin supplements is widely recommended to support maternal homeostasis during pregnancy. Our objective was to investigate whether multivitamin use during pregnancy is associated with a reduced risk of pre-eclampsia. The effect of multivitamin use on incidence of pre-eclampsia in lean and overweight/obese women was analysed using data collected between 2006 and 2011 as part of the Environments for Healthy Living Project, Griffith University, Australia. A total of 2261 pregnancies were included in the analysis with pre-eclampsia reported in 1.95% of subjects. Body mass index (BMI) ≥ 25 was associated with a 1.97-fold [95% confidence interval (CI): 0.93, 4.16] increase in pre-eclampsia risk. First trimester multivitamin use was reported by 31.8% of women and after adjustment, was associated with a 67% reduction in pre-eclampsia risk (95%CI: 0.14, 0.75). Stratification by BMI demonstrated a 55% reduction in pre-eclampsia risk (95%CI: 0.30, 0.86) in overweight (BMI: 25-29.9) and 62% risk reduction (95%CI: 0.16, 0.92) in obese (BMI: ≥30) cohorts that supplemented with multivitamins in the first trimester of pregnancy. This finding may be particular to the Australian population and reflect inherent nutritional deficits. First trimester folate supplementation was found to reduce pre-eclampsia incidence [adjusted odds ratios (AOR) 0.42 95%CI: 0.13, 0.98] and demonstrated significance upon stratification by overweight status for women with BMI >25 (AOR 0.55 95%CI: 0.31, 0.96). These results support the hypothesis that multivitamin supplementation may be beneficial in reducing the incidence of pre-eclampsia during pregnancy and be of particular importance for those with a BMI ≥25.