Women can breastfeed an infant with phenylketonuria (PKU), along with feeding their baby the required amount of specialized PKU formula. Breast milk contains very low levels of phenylalanine (only 12 to 14 mg of Phe per ounce in one study), lower than most of the commercially available formula on the market (24 to 28 mg of Phe per ounce). It is important to work with a metabolic dietitian experienced with PKU closely if you would like to breastfeed your baby. To find a metabolic dietitian specializing in diets for people with metabolic conditions including PKU, visit the GMDI Find a Metabolic Dietitian webpage.
Other Questions About Phenylketonuria
- Will my child with phenylketonuria go through puberty the same time as their peers?
- Will my child with phenylketonuria be able to live independently?
- Will my child outgrow phenylketonuria?
- Will my child have to use medical food product for phenylketonuria for their entire life or just a period of time?
- Why is phenylketonuria considered an amino acid disorder?

