Two successful pregnancies in pyridoxine-nonresponsive homocystinuria.

Two successful pregnancies are reported in a pyridoxine-nonresponsive woman who was also homozygous for the MTHFR 677C>T polymorphism. Two healthy children were delivered, although there had also been an early miscarriage of an apparently normal fetus in another pregnancy. Management of the patient's homocystine and methionine levels was maintained throughout pregnancy and, in view of the increased thromboembolic risk, anticoagulation therapy was also included in management.