PREGNANCY AND INFANT OF MOTHER WITH HYPER PHENYLALANINEMIA

Pregnant women with hyperphenylalaninemia are at high risk of spontane ous abortion and of giving birth to infants with congenital malformati ons, microcephaly and mental defect. Among mothers whose phenylalanine mia is greater than 1200 mu mol/L (20 mg/100 mL). 95% have at least on e child with mental retardation. A low phenylalanine diet with a good control of phenylalaninemia, started before conception, reduces this r isk, better results being obtained when plasma phenylalanine levels ar e maintained below 360 mu mol/L (6 mg/100 mL) as compared with levels maintained between 360 to 600 mu mol/L (6-10 mg/100 mL). Thus, systema tic contraception and planned pregnancies must be recommended in all h yperphenylalanemic young women. This implies early information of phen ylketonuric teenage girls and their parents. In addition, efforts must be made to join and inform all women having had hyperphenylalaninemia at birth, whether they received a dietary treatment or not. It is als o important that general practitioners, pediatricians and obstetrician s be aware of the high recurrence risk in hyperphenylalanemic women wh o gave birth to a microcephalic or malformed infant.