Recommendations for maternal phenylketonuria

The American Academy of Pediatrics (AAP) recommends the following for preventing and managing maternal phenylketonuria (PKU):¹

• All women and girls of childbearing age with elevated phenylalanine (Phe) levels should be identified and counseled about the effects that high Phe may have on a fetus.
• Women with elevated Phe levels who are unable or unwilling to maintain recommended levels of Phe should be assisted in finding adequate means of birth control.
• Pregnant women with Phe levels greater than 4 mg/dL to 6 mg/dL should receive counseling concerning the risks to the fetus and should be offered ultrasound tests to detect fetal problems.
• Pregnant women with Phe levels greater than 14.9 mg/dL may consider terminating the pregnancy.
• A woman should have a blood test for PKU if her child has features that suggest the mother had high phenylalanine (Phe) levels during pregnancy. For example, her baby may be born with a very small head (microcephaly) and heart problems. The AAP recommends that the mother is tested for PKU when there is no other known cause for the baby's symptoms.

A woman who has PKU and is considering pregnancy or is pregnant should:

• Achieve low levels (below 6 mg/dL) of Phe at least 3 months before conception.²
• Get tested at least once a week.
• Receive adequate nutrition.

Citations

1. Committee on Genetics, American Academy of Pediatrics (2001). Maternal phenylketonuria. Pediatrics, 107(2): 427-428.

2. Kaye CI, and the Committee on Genetics, American Academy of Pediatrics (2006). Phenylketonuria section of Newborn screening fact sheets: Technical report. Pediatrics, 118(3): e956-e957.