CDC scientists collaborated with Beijing Medical University to evaluate the outcome of pregnancy among women who were asked to take a pill containing only 400 micrograms (µg) of folic acid daily from the time of their premarital examination until the end of their first trimester of pregnancy. This collaboration was part of a public health campaign conducted from 1993 through 1995 in an area in northern China with high rates of neural tube defects and one in southern China with low rates.

• The daily ingestion of a pill containing only 400 µg of folic acid before and during early pregnancy reduced a woman’s risk of having a fetus or infant with a neural tube defect. This reduction occurred both in an area of China in which the frequency of neural tube defects is high and one in which it is low.
    

• The greatest preventive effect (85% reduction in risk) occurred in the northern region of China among women who started taking pills before they became pregnant and who had high pill-taking compliance.
    

• The preventive effect (41% reduction in risk) in the southern region of China, in which the baseline rate is similar to that seen in the United States and other countries, suggests that women in these countries may reduce their risk of having a fetus or infant with a neural tube defect by consuming only 400 µg of folic acid on a daily basis before and during early pregnancy.
    

• These results are being used to support and promote activities to prevent neural tube defects around the world.

Results published in : New England Journal of Medicine 1999;341:1485-1491. (Abstract) 

Date: June 17, 2005
Content source: National Center on Birth Defects and Developmental Disabilities