Multivitamin use and risk of preeclampsia in a high-income population: A cohort study

The objective of this study was to examine the association between multivitamin use in the periconceptional period and the risk of preeclampsia.

The association was investigated in a prospective cohort study. 15,154 deliveries in women followed at a large university hospital in Denmark were included between 16 September 2012 and 31 October 2016. Pregnant women were sent a questionnaire containing items related to socio-demographic-, lifestyle- and health factors. The responses on multivitamin use were merged with the preeclampsia diagnosis from the Danish Medical Birth Registry. We used multiple logistic regression analyses to assess the association and to adjust for potential confounders.

The outcome of interest, preeclampsia, included the preeclampsia subtypes eclampsia and HELLP (Haemolysis, Elevated Liver enzymes, and Low Platelets) syndrome.

In total 12,954 women (85%) reported multivitamin use. A diagnosis of preeclampsia was found in 397 women (2.6%). We found a similar risk of preeclampsia in multivitamin user and non-users, adjusted odds ratio (AOR) for periconceptional multivitamin use = 0.97 (95% CI: 0.70 to 1.36) and AOR for early pregnancy multivitamin use = 0.97 (95% CI: 0.71 to 1.32). Subgroup analyses stratified on body mass index showed that among women with overweight, both periconceptional and early pregnancy multivitamin use were associated with a statistically significant lower risk of preeclampsia (AOR = 0.49, 95% CI: 0.24 to 0.99 and AOR = 0.35, 95% CI: 0.18 to 0.69, respectively).

Periconceptional- and early pregnancy multivitamin use was found to be associated with a similar risk of preeclampsia compared to non-users.