initial distinction was made in the research article “Post-Partum Necrosis of the Anterior Pituitary”. In his research, Dr. Sheehan reviewed (through autopsy) the effects of pituitary necrosis on 12 cases of patients that experienced postpartum necrosis. He observed cases where lesions and death occurred during or after pregnancy, as well as cases where death occurred in the late stage of necrosis (years later). This started the initial distinction of Sheehan’s syndrome from Simmonds’ disease (also known as hypopituitarism). Dr. Sheehan noted that significant feature of these patients' cases was hemorrhaging, which in his experience was most commonly caused by either: placenta Previa (low placenta), uterine rupture, cervical or uterine tears, post-partum atony, or retained placenta. Simmonds' disease, however, occurs in either sex due to causes unrelated to pregnancy. However, in his 1939 publication: “Simmonds’ Disease due to Post-partum Necrosis of the Anterior Pituitary”, Dr. Sheehan displays post-partum necrosis as a cause of Simmonds’ disease, thus establishing the relationship between the two conditions. According to Sheehan in 1939 approximately 41% of survivors of severe postpartum hemorrhage (PPH) and/or hypovolemic shock experienced severe or partial hypopituitarism. Society and Culture In the developed world Sheehan’s Syndrome is a rare complication of pregnancy; although this syndrome is more prevalent in developing countries it continues to effect women around the world. A retrospective study in Turkey found that the prevalence of Sheehan’s syndrome was directly proportional to the amount of at-home deliveries each decade. This may be due to previously limited obstetric techniques present in a home environment. Research At present, the part that autoimmunity plays in the development of Sheehan's syndrome is uncertain. Several case reports have identified anti-pituitary antibodies in patients diagnosed with Sheehan's. Some patients also tested positive for anti-hypothalamus antibodies. Given that many patients that have developed Sheehan's syndrome do not have detectable levels of these antibodies, it is unclear whether these antibodies cause this syndrome or result from it. References External links Pituitary disorders Obstetrics Syndromes