Limited evidence suggests that healthy maternal dietary patterns during the preconception period that are higher in vegetables, fruits and grains; lower in red and processed meats; and low in sweets were associated with lower risk of developing of neural tube defects, particularly among women who do not take folic acid supplements. Whereas some dietary patterns were associated with lower risk of developing anencephaly, others were associated with lower risk of developing spina bifida.
Evidence is insufficient to determine an association between maternal dietary patterns and congenital heart defects or cleft lip and palate.
All studies were consistent in demonstrating that folic acid supplementation periconceptionally was associated with a decreased risk of having a child with a birth defect (e.g., neural tube defects, congenital heart defects, and cleft lip and palate).
Grade: Limited: Neural tube defects Not assignable: Congenital heart defects Not assignable: Cleft lip/palate