A U.S study suggests that women who take folic acid supplements before they become pregnant can cut their risk of having a premature baby by half.

The report, presented Thursday at the annual Society for Maternal-Fetal Medicine meeting, said taking folate supplements for at least one year before becoming pregnant reduced premature delivery by 50 percent to 70 percent.

Babies who are born very premature are at the greatest risk of complications such as cerebral palsy, mental retardation, chronic lung disease and blindness.

The findings were based on observational analysis of folate supplementation by 38,033 participants in an earlier trial sponsored by the National Institutes of Health.

"Thanks to the depth and breadth of the NIH study, which included an early pregnancy ultrasound of each participant, we had highly accurate evidence of the gestational ages of the preterm deliveries," Dr. Radek Bukowski of the University of Texas Medical Branch at Galveston said in a release.

Folate supplements were linked to a 70 percent decrease in very early preterm deliveries between 20 to 28 weeks in gestational age, and up to a 50 percent reduction in early preterm deliveries of 28 to 32 weeks.

Copyright 2008 by United Press International