Nutrition Management of Maternal Metabolic Disorders

Children born to mothers with phenylketonuria (PKU) who have high blood phenylalanine during pregnancy are at risk of developing intellectual disability, microcephaly, congenital heart defects, low birth weight and facial dysmorphism. Women with PKU should maintain blood phenylalanine below 360 µmol/L before and during pregnancy for optimal pregnancy outcomes. In inherited metabolic disorders other than PKU, the fetus does not appear to be at risk; however, the mother is at risk of metabolic crises associated with catabolism during pregnancy or in the post-partum period unless energy intake is sufficient. The maternal diet for amino- and organic acidopathies typically includes a disease-specific medical food as the main source of protein, a limited amount of intact protein, and sufficient energy, fat, vitamins and minerals to support fetal growth.