Hazards associated with pregnancies and deliveries in lysinuric protein intolerance

Lysinuric protein intolerance (LPI) is an autosomal recessive transport disorder of the dibasic amino acids. The defect leads to deficiency of lysine, arginine, and ornithine and, secondarily, to a functional disorder of the urea cycle. Transient postprandial hyperammonemia and subsequent persistent protein aversion, linked with several other biochemical and clinical characteristics of the disease, suggest an increased risk for maternal and fetal complications during pregnancy and delivery. Our unique material on the outcomes of 18 pregnancies of 9 Finnish mothers with LPI and the follow-up of their 19 children shows that maternal LPI is truly associated with increased risk of anemia, toxemia, and intrauterine growth retardation during pregnancy and bleeding complications during delivery. Successful pregnancies and deliveries can still be achieved with careful follow-up of blood pressure and laboratory values. The children of the mothers with LPI generally develop normally. Special care of maternal protein nutrition and control of ammonemia, anemia, and toxemia during pregnancy are essential. We propose centralization of deliveries to obstetric units with capability to deal with bleeding complications and rare inborn errors of metabolism.