The Randomized Controlled Trial of Periconceptional Multivitamin Supplementation on Structural Birth Defects and Pregnancy Outcomes, 1984-1994
Investigator: Andrew E. Czeizel

The Randomized Controlled Trial of Periconceptional Multivitamin Supplementation on Structural Birth Defects and Pregnancy Outcomes was conducted between 1984 and 1994 at the Family Planning Center in Budapest, Hungary. The study was conducted to test the preventive effect of periconceptional multivitamin supplementation on the first occurrence of neural tube defects and other congenital abnormalities. The study was a randomized double-blind controlled trial involving 4,862 informative offspring from 4,783 women. Women planning a pregnancy were randomly assigned to receive a single tablet of a vitamin supplement or a trace-element supplement daily for at least one month before conception and until the date of the second missed menstrual period or later. Up to four visits with study staff took place during the study. Pregnancy outcomes were evaluated prenatally, shortly after birth, and during a follow-up medical examination after the infants' 8th month of life. The dataset contains 37 variables collected from 4,862 informative offspring.