THE INTERNATIONAL COLLABORATIVE STUDY OF MATERNAL PHENYLKETONURIA - STATUS-REPORT 1994

Neonatal screening for phenylketonuria (PKU) has created a problem as females with PKU are reaching child-bearing age. Surveys have revealed that maternal phenylalanine blood concentrations greater than 1200 mu mol/l are associated with fetal microcephaly, congenital heart defect s and intrauterine growth retardation. It is estimated that as many as 3000 hyperphenylalaninemic females may be at risk of producing these fetal abnormalities. To examine this problem, the international matern al PKU collaborative study was developed to evaluate the efficacy of a phenylalanine-restricted diet in reducing fetal morbidity. Preliminar y findings have indicated that phenylalanine restriction should begin before conception for females with PKU planning a pregnancy. Dietary c ontrol should maintain maternal blood phenylalanine levels between 120 and 360 mu mol/l and should provide adequate energy, protein, vitamin and mineral intake. Pregnant hyperphenylalaninemic females who achiev ed metabolic control after conception or by the 10th week of pregnancy had a better offspring outcome than anticipated. The results of 402 p regnancies are reviewed.