Sheehan1in 1937 reported twelve cases of necrosis of the anterior lobe of the pituitary occurring in a consecutive fatal series of seventy-six women, seventeen of whom died in late pregnancy or at delivery and fifty-nine during the puerperium. He was able to collect from the literature thirty-six additional cases of pituitary necrosis following delivery. Of these forty-eight cases, twenty-seven were recent and twenty-one healed lesions of the pituitary. Sheehan, from a study of these cases, states that necrosis of the anterior pituitary is a relatively frequent finding in women dying during the puerperium. According to this author, the necrosis begins about the time of delivery and is due to thrombosis of the pituitary vessels. This often follows symptoms of collapse when the latter is due to hemorrhage. If the patient survives this pituitary necrosis in the puerperium she often develops symptoms of pituitary insufficiency ranging from Simmond's disease