Abstract
1. A hemophilia-like disease acquired during the first pregnancy of a young woman, is described.
2. The clotting abnormality was caused by a circulating anticoagulant which, in all probability, inhibited the antihemophilic globulin.
3. The anticoagulant was demonstrated in the patient's second child during his first two and one-half months of life.
4. The transplacental transfer of the anticoagulant and the analogy of this condition to hemophilia (resistant to therapy) following iso-immunization against antihemophilic globulin, strongly suggest that an immunologic mechanism accounts for the development of this abnormality.
5. The patient recovered eighteen months after her second delivery and sixteen months after x-ray sterilization. The possible relation between endocrine factors and recovery is discussed.
