Pregnancy in women with inherited metabolic disease.

An increasing number of women with rare inherited disorders of metabolism are becoming pregnant. Whilst, in general, outcomes for women and their children are good, there are issues that need to be considered. Due to the rarity of many conditions, there is limited specific guidance available on best management. Prepregnancy counselling with information on inheritance, options for reproduction, teratogenicity risk, potential impact on maternal health and long-term health of children should be offered. With appropriate specialist management, the teratogenic risk of conditions such as maternal phenylketonuria (PKU) can be eliminated, and the risk of metabolic decompensation in other disorders of intoxication or energy metabolism significantly reduced. Newer therapies, such as enzyme replacement therapy, appear to be safe in pregnancy, but specific advice should be sought. Multidisciplinary management, and close liaison between obstetricians and other specialists is required for women in whom there is cardiac, renal, respiratory, joint or other organ involvement.