[Inherited metabolic diseases and pregnancy: consequences for mother and child].

The prevalence of individual hereditary metabolic diseases is low, but together they constitute an important group in which pregnancy is of growing interest because patients more often reach adulthood and consider progeny. Hereditary metabolic diseases of the woman, such as hyperhomocystinemia or urea cycle defect, can present during or directly after pregnancy for the first time with thrombosis or coma, respectively. Other hereditary metabolic diseases of the woman, such as glycogen storage disease type I or III, can progress during pregnancy and may result in renal insufficiency or cardiomyopathy. Maternal hereditary metabolic diseases, such as poorly controlled hyperhomocystinemia or phenylketonuria, can deleteriously affect the foetus. Hereditary metabolic diseases of the foetus may have implications for the foetus itself, e.g., lysosomal storage diseases of the foetus may cause hydrops foetalis, cardiomyopathy, or foetal demise. In addition, hereditary defects of long chain fatty acid oxidation of the foetus may result in severe haemolysis and elevated liver enzymes and low platelets, or acute fatty liver of pregnancy in the mother.