Folate in Early Pregnancy Linked to Slightly Raised Risk of Respiratory Ills in Infants
Arch Dis Child 2008.
NEW YORK (Reuters Health) Dec 02 - Offspring of mothers who use folate supplements during their first trimester appear to have a slightly higher incidence of wheeze and lower respiratory tract infections up to 18 months of age, according to findings of a study conducted in Norway.
Because these findings are preliminary, "women should not panic and they should definitely continue with their folic acid supplements," lead author Dr. Siri E. Haberg stressed in an interview with Reuters Health.
Mothers are advised to increase their folic acid intake during their childbearing years to reduce the risk of congenital malformations in their offspring, Dr. Haberg and co-authors note in the Archives of Disease in Childhood published online on December 2. However, studies in mice indicate that folic acid increases gene methylation during pregnancy and causes allergic asthma phenotypes in offspring through epigenetic mechanisms.
Dr. Haberg, at the Norwegian Institute of Public Health in Oslo, and her associates analyzed data from the Norwegian Mother and Child Cohort. The current study included 32,077 children born between 2000 and 2005.
According to questionnaire responses, 22.3% of mothers used folate supplements in the first trimester only and 42.6% used supplements throughout pregnancy.
After adjusting for folate exposure later in pregnancy and in infancy, the relative risk for wheeze for children up to 18 months of age exposed in the first trimester was 1.06. Corresponding relative risks for lower respiratory tract infections and for hospitalizations for lower respiratory tract infections were 1.09 and 1.24, respectively.
These results were statistically significant. However, "It is important to emphasize that pregnant women should not change their supplement use based on these findings," Dr. Haberg said.
As she pointed out, "documentation of the preventive role of folic acid supplements in congenital malformations is well established, while our data (regarding respiratory illness in early childhood) are only the first such findings in humans, and we don't even know if the association is causal."