Trends in folic acid supplementation during pregnancy – the effect on allergy development in children

Introduction
The results of some previous studies suggested that maternal folate supplementation during pregnancy may contribute to allergy development in offspring.

Aim
This study was performed to examine the influence of maternal folic acid intake prior to and during pregnancy on the development of various types of allergy in children taking into account the timing and dosage of supplemented folate.

Material and methods
The retrospective study was performed between 2010 and 2014 in 307 child-mother pairs (203 allergic children and 104 children without allergy symptoms, aged 2–72 months). Allergy diagnosis was based on medical history, physical examination, positive results of allergic tests: specific IgE and/or skin prick tests and double-blind, placebo-controlled food challenge. The data concerning maternal folate supplementation prior to and during pregnancy were obtained based on a questionnaire.

Results
Mothers of allergic children used to take folic acid more frequently in the preconception period (42.9%), in the 1st (94.1%) and the 2nd/3rd (81.3%) trimester of pregnancy than mothers of the healthy ones (30.8%, 82.7% and 55.8%, respectively) (p < 0.05). Maternal intake of folate in a dosage higher than recommended (> 0.4 mg/day) was more often observed in the group of allergic subjects, especially in children with combined sensitization to food and inhalant allergens, than in the control group (p < 0.05).

Conclusions
Our results suggest an impact of maternal folic acid supplementation prior to and during pregnancy on allergy development in children. Further observations are required to establish the role of folate in fetal epigenetic modifications.