Maternal folate exposure in pregnancy and childhood asthma and allergy: a systematic review

Area of Science:

• Obstetrics and Gynecology
• Pediatric Allergy and Immunology
• Nutritional Epidemiology

Background:

• Adequate maternal folate status is crucial for preventing congenital malformations.
• The impact of folic acid supplementation, especially exceeding recommended doses, on long-term child health remains unclear.
• Conflicting evidence exists regarding maternal folate levels and the risk of childhood asthma and allergic diseases.

Purpose of the Study:

• To systematically review the epidemiologic evidence linking maternal folate exposure to childhood asthma and allergic disease.
• To synthesize findings from prospective cohort studies, considering methodological variations and limitations.
• To provide direction for future research on this topic.

Main Methods:

• Systematic review of 10 large prospective cohort studies.
• Analysis of epidemiologic data on maternal folate levels and childhood asthma/allergic disease risk.
• Evaluation of study methodologies and potential limitations.

Main Results:

• The majority of studies found no significant association between maternal folate levels and childhood asthma or allergic disease.
• A small, transient increase in risk was observed in some studies, primarily linked to late-pregnancy folic acid supplementation.
• The observed associations were generally confined to early childhood.

Conclusions:

• Current evidence on the link between maternal folate exposure and childhood asthma is conflicting.
• A potential transient increase in risk may be associated with late-pregnancy folic acid supplementation.
• Further research is warranted to elucidate the complex relationship and potential confounding factors.