It's well known that folic acid taken very early in pregnancy can reduce the risk of birth defects. Now comes news that women who take folic acid for at least one year before they become pregnant can cut their risk of a premature birth by 50 to 70 per cent -- regardless of other factors that can affect prematurity, such as the age of the mother.

The study was unveiled at this year's Society for Maternal-Fetal Medicine (SMFM) meeting.

Researchers observed 38,033 women from an earlier study and noted their self-reported folic acid intake. They found that folate supplementation for at least one year before pregnancy was linked to a 70 per cent decrease in very early preterm deliveries (20 to 28 weeks in gestational age) and up to a 50 per cent reduction in early preterm deliveries of 28 to 32 weeks."

The study only looked at women who had singletons, not twins or other multiples, and excluded pregnancies that had complications, such as preeclampsia or congenital or chromosomal abnormalities.

The findings are significant because babies born very prematurely are at the greatest risk of complications such as cerebral palsy, mental retardation, chronic lung disease, and blindness.

Dr. Alan R. Fleischman, senior vice president and medical director of the March of Dimes, which promotes folic acid supplementation to prevent birth defects, says the study provides women considering pregnancy one more reason to begin taking 400 micrograms of folic acid daily.

"We hope this new research also will spur more health care professionals to urge their female patients to make folic acid part of their daily routine as a simple step toward having a healthy baby in the future," he said in a statement.

Dr. Katharine Wenstrom, president of the SMFM says folic acid offers many benefits and everyone should take it.

"In addition to its benefits in preventing pregnancy complications, previous studies have suggested that folic acid may also have beneficial effects in preventing stroke and cardiovascular disease in adults," she said. "That's why everyone --men and women-- should get into the habit of taking it."