Studies of fibrinogen and other hemostatic factors in women with intrauterine death and delayed delivery.

Studies of the concentration of fibrinogen in plasma were made in a total of 31 patients who remained undelivered 3 or more weeks after apparent intrauterine fetal death. Serial determinations were made before during and after labor and delivery wherever possible. In these laboratories the concentration of fibrinogen in the plasma of 36 normal nonpregnant women averaged 294 milligrams per 100 milliliters ranging from 164 to 485 milliligrams per 100 milliliters with a standard deviation of the mean of 58.8. Hypofibrinogenemia was thought to exist when the plasma concentration was less than 150 milligrams. In 23 patients in whom fetal death appeared to have occurred between the 12th and 36th week of gestation and the dead fetus had been retained in utero for 3-11 weeks no evidence was found of a critical depletion of circulating fibrinogen. The concentration of fibrinogen at delivery ranged from 321 to 652 milligrams per 100 milliliters of plasma. In 7 patients serial fibrinogen determinations were made for several weeks following intrauterine death. In all 7 there was evidence of a progressive reduction in the concentration of circulating fibrinogen. The decrease took place in roughly linear fashion but the concentration of fibrinogen at no time reached a level lower than that in the normal nonpregnant women. During the same period 8 cases of prolonged intrauterine retention of a dead fetus were encountered in which the level of fibrinogen was dangerously low. Some case studies are included.