Breastfeeding in phenylketonuria

Eighty-three infants with classical phenylketonuria have been born in Norwa y since 1979. The treatment of these children is centralized at the Nationa l Hospital in Oslo. Seventy-four have been breastfed in combination with a phenylalanine-free protein substitute. Dietary treatment was commenced in h ospital between 5 and 33 d of age (mean 14 d). Normalization of serum pheny lalanine (below 400 mu mol/l) took between 1 and 35 d (mean 8 d). The perio d of breastfeeding lasted from 1 to 16 mo (mean 7 mo). Growth (weight, leng th and head circumference) fell within the normal range for age on the Norw egian growth chart.