Oral D-mannose therapy during pregnancy in a woman with MPI-CDG: A case report and management review.

Mannose 6-phosphate isomerase deficiency is a rare disorder of N-glycosylation leading to impaired coagulation, enteropathy, hypoglycemia and liver disease. D-mannose is the only available treatment. We report the case of a pregnant woman with MPI-CDG and the management of D-mannose therapy during pregnancy. D-mannose was discontinued at 6 weeks' gestation, due to the potential fetal toxicity observed particularly in animal models, but severe digestive symptoms and hypoglycemia relapsed. We decided to readminister D-mannose therapy at 10 weeks' gestation although data on teratogenecity in humans are lacking. Symptoms resolved rapidly when D-mannose was resumed. Monitoring of transferrin glycoforms profile and coagulation parameters allowed to gradually increase D-mannose dosage throughout pregnancy. The patient delivered at 38 weeks' gestation after an intrauterine growth retardation was noted. The infant was 2.390 kg at birth with a low Apgar score but rapidly recovered. Low dose D-mannose treatment administered from 10 weeks' gestation could be a safe option for women with MPI-CDG.