It has been known for 20 years that folic acid (folate) supplements taken during pregnancy reduce the risk of neural tube defects and possibly other congenital malformations.
However, in recent years it has been suggested that folate, an important regulator of a complex set of pathways necessary for fetal development, may also increase the risk of other diseases in exposed children, particularly allergies and asthma.
In a new study by the Yale School of Public Health, 1,499 women were followed from the first trimester of their pregnancy, and their children were followed to age six. No association was found between childhood asthma and the mother’s use of folic acid in pregnancy, the time in pregnancy during which folate was used or the dose administered.
“Public health interventions affecting the diet of entire populations must be most carefully assessed for possible harms,” said Michael B. Bracken, the Susan Dwight Bliss Professor of Epidemiology and the study’s senior author. “While the current analysis is reassuring, more work studying the safety of higher doses of folate, than were measured in this study, are needed.”
Just over half of the mothers in the study used folate in the month before conception and 88 percent in the third month of pregnancy. By age six years, 15 percent of the children had been diagnosed with asthma. This is a higher rate than normally expected because the study focused on mothers at particular risk for having asthma.
The study was conducted at the Yale Center for Perinatal, Pediatric and Environmental Epidemiology. Three visiting scholars, Marit Martinussen, Kari Risnes and Geir Jacobsen, all of whom are from the Norwegian University of Science and Technology in Trondheim, contributed to the study.
The Yale Center is engaged in a broad research program to examine the causes of childhood asthma, which is reaching epidemic proportions in some parts of the world, including indoor and outdoor air pollutants, medication use and other life style factors in pregnancy and early childhood, as well as genetic causes.
The study appears in the current issue of the American Journal of Obstetrics and Gynecology.