Maternal phenylketonuria: comparison of two treated full term pregnancies.

This case report documents the fetal outcome of two full term pregnancies in a patient with phenylketonuria (PKU). She was treated with a low phenylalanine diet preceeding and during both pregnancies. During her first full term pregnancy she was not able to maintain the rigid diet, and this pregnancy resulted in the delivery of a growth-retarded, microcephalic boy. In her second pregnancy the patient maintained the diet until her delivery at full term. Maternal blood phenylalanine levels remained with two exceptions below 600 mumol/l throughout pregnancy and an infant of normal weight and head circumference was born.