Reduced thromboplastin activity in blood monocytes and reduced sensitivity to stimuli in vitro of blood monocytes from pregnant women.

The thromboplastin activity in blood monocytes from 18 normal third trimester pregnant women has been compared with a group of 20 healthy non-pregnant women. The thromboplastin activity in unstimulated monocytes from the normal pregnant group was on average 40% of the activity in the non-pregnant group (P less than 0.01). In endotoxin stimulated monocytes, the thromboplastin activity was also significantly lower in the pregnant group as compared to the non-pregnant group (P less than 0.001). Fibrinogen and factors V, VII and VIII were significantly higher in the pregnant than in the non-pregnant group, whereas no difference was observed in AT-III, prekallikrein and alpha 2-antiplasmin levels.