Folic acid is vital for the development of the fetal nervous system. Taking it before conception and throughout the first trimester decreases the risk of having a child born with a neural tube defect. Doctors recommend expectant mothers take 400 mcg of folic acid daily before conception and during the first trimester. However, researchers in Australia have determined that taking folic acid after 12 weeks of pregnancy increases the risk of childhood asthma.
What Is Folic Acid?
Folic acid is a vitamin the cells need to make DNA, the red blood cells must have to mature, and the nervous system of the fetus needs to develop. It is common that people do not consume enough of this vitamin, since overcooking destroys it. Certain medications, disease and malnutrition as a result of alcoholism can lead to a folic acid deficiency as well.
Folic Acid Benefit in First Trimester
As of 2004, approximately 3,000 infants are born with neural tube defects every year, a decrease from 4,000 a year as a result of folic acid being added to cereal products, F. Gary Cunningham, M.D., distinguished chair in obstetrics and gynecology at the University of Texas Southwestern Medical Center writes in “Williams Obstetrics.” Cunningham also writes that more than 50 percent of neural tube defects could be prevented if women took 400 mcg of folic acid every day before conceiving. He emphasizes they should continue to take it during their first trimester, or first 13 weeks.
According to the Department of Health and Human Services, women should take folic acid during the time when neural tube defects may happen, which is during the first trimester. The first trimester is the most crucial time for the tissues and organs to develop and mature. Tissues and organs develop during the third to eighth weeks of fetal development, making this the most sensitive time for birth defects to occur.
Possible Danger with Taking After 12 Weeks
A study in the October 2009 issue of the “American Journal of Epidemiology” determined that folic acid supplements taken during late pregnancy greatly increased the risk of children developing asthma when 3.5 to 5.5 years old, with 11.6 percent having asthma by 3.5 years of age and 11.8 percent at 5.5 years. This group of researchers did not find any such risk in the children of women who took supplements in the first 12 weeks. They hypothesize that folic acid supplements taken during late pregnancy are the reason for the increase in asthma.
- "American Journal of Epidemiology"; Effect of Supplemental Folic Acid in Pregnancy on Childhood Asthma; Melissa Whitrow, et al.; August 2009
- Department of Health and Human Services: Folic Acid
- Merck Manual Professional: Folate: Vitamin Deficiency, Dependency, and Toxicity
- “Williams Obstetrics”; F. Gary Cunningham, M.D., et al.; 2010