Maternal phenylketonuria: a case report - Revista Brasileira de Ginecologia e Obstetrícia

Maternal phenylketonuria is an aminoacid pathology characterized by elevated plasma levels of phenylalanine in the pregnant woman that may cause abnormalities in fetus development, and which is called maternal phenylketonuria syndrome. As the clinical manifestations are non-specific, the disease should be diagnosed by laboratory screening. We present a case of a second pregnancy in a woman with a history of psycho-cognitive development retardation without previous obstetric history, with diagnosis of phenylketonuria in the present gestation, treated with specific phenylalanine-free diet. The newborn did not present congenital defects. The previous gestation without maternal treatment resulted in a child with serious developmental disturbances, microcephalia and auditory-speaking deficits. Early diagnosis and treatment of hyperphenylalaninemia during pregnancy are essential, mainly because of the negative impact on fetal development. In the here reported case, there were fetal benefits from the maternal dietary treatment, which demonstrates the importance of the maternal diagnosis of phenylketonuria in women in reproductive age.