Dietary treatment in maternal phenylketonuria

Background: Maternal phenylketonuria (PKU) is an embryo-fetal syndrome incl uding microcephaly and various organ (mainly cardiac) defects. It is caused by the toxicity of high phenylalanine levels in the blood from mothers wit h PKU who usually are off diet as adults. Maternal PKU is prevented by stri ct dietary phenylalanine restriction during pregnancy. Patients and results: In Austria since 1967, 59 female PKU patients were bo rn who at present time are between 16-32 years of age. We report on 11 preg nancies from 6 women with PKU who asked for dietary treatment during pregna ncy. 5 newborns from 5 pregnancies with good dietary control (preconception ally and during the entire period of pregnancy) were normally developed dur ing an up to 5 year-somatic and neurodevelopmental follow up. In one pregna ncy dietary control was achieved only after the first 5 weeks of pregnancy, The respective newborn had congenital heart disease, but otherwise was dev eloped normally. 3 newborns from 1 mother who was not able to achieve dieta ry control during the entire period of pregnancy, had typical symptoms of p henylalanine embryofetopathy. 2 pregnancies were terminated by spontaneous abortion despite preconceptional dietary control. Conclusion: Preconceptional dietary balance and low blood phenylalanine lev els are important for normal embryo-fetal development. The dietary manageme nt of pregnant PKU women should be carried out in specialized metabolic cen ters with experience in the treatment of PKU in close cooperation with the obstetritian.