493thromboplastin or other substances from the ioc sac into the maternal circulation, resulting in the connuous consmption of fibrinogen The increased incidce of oic fluid embolism with intrauterine death of the fetus may be due to the increased friability of the membranes, which are therefore more likely to split or tear, thus creating favourable conditions for amniotic fluid infusion during labour and delivery.We should like to thank Professor Stallworthy for pernmission to usw the clinical material, and Dr. Phizackerley, department of biochemistry, for his advice.