Maternal phenylketonuria pregnancy outcome: a preliminary report of facial dysmorphology and major malformations

It is clear from the preliminary data that major malformations, i.e. intrauterine growth retardation, microcephaly and cardiac defects, tend to decrease in frequency as the blood phenylalanine level drops, but not enough to suggest that phenylalanine levels of 600 μmol/L are safe levels. The facial dysmorphic features may be used as a sensitive indicator that blood phenylalanine levels should be below 360 μmol/L. It is hoped that at the end of the collaborative study more data will be available to suggest blood phenylalanine levels which will prevent the deleterious effects of maternal PKU syndrome.