Higher Rate of Multiple Births after Periconceptional Vitamin Supplementation

To the Editor: Periconceptional supplementation with multivitamins including folic acid or with folic acid alone can reduce both the first occurrence and the recurrence of neural-tube defects1–3. We examined the effect of such supplementation on multiple births. The Hungarian trial of periconceptional multivitamin supplementation was stopped in 1992, and the outcomes of the pregnancies were evaluated one year later1. The multivitamin supplement contained 12 vitamins, including 0.8 mg of folic acid, four minerals, and three trace elements; a control supplement contained three trace elements. Pregnancy was confirmed in 5502 women, and outcome could be evaluated in 5453. . . .