Preterm birth is associated with many health risks as well as a lower rate of infant survival during the first year of life. Women who take a multivitamin before conception have only half the risk of preterm delivery than those who wait until after becoming pregnant to start taking nutritional supplements.
A study published in the November 2004 issue of the American Journal of Epidemiology showed that the use of multivitamin supplements by women prior to becoming pregnant was associated with fewer preterm deliveries. Preterm birth is defined as birth at less than 37 weeks of gestation and is associated with a lower rate of infant survival during the first year of life.
Researchers utilized data from the Pregnancy, Infection and Nutrition Study which recruited 2,010 women during their 24th to 29th week of pregnancy. They compared the incidence of preterm delivery among women who took multivitamins prior to conception, before conception and during pregnancy, during pregnancy only, or not at all.
Women who took a multivitamin supplement before conception had half the risk of early and late preterm delivery than those who took no vitamins. Women used multivitamins during pregnancy only had approximately the same amount of preterm births than women who took none at all.
This study, as well as many previous studies, reinforces the concern that waiting until pregnancy is diagnosed may be too late for nutritional intervention to benefit many pregnancy outcomes.
Am J Epidemiol. 2004 Nov 1;160(9):886-92.