A primer on pituitary injury for the obstetrician gynecologist: Simmond's disease, Sheehan's Syndrome, traumatic injury, Dahan's Syndrome, pituitary apoplexy and lymphocytic hypophysitis.

The pituitary gland plays a critical role in reproduction. In response to the hypothalamus the anterior pituitary secretes prolactin, thyroid-stimulating hormone, adreno-corticotropic hormone, follicle-stimulating hormone, luteinizing hormone and growth hormone. Dysregulation in these hormones often lead to reproductive failure. Multiple mechanisms of pituitary injury exist. Simmond's disease is atrophy or destruction of the anterior lobe of the pituitary gland resulting in hypopituitarism. Sheehan's syndrome is post-partum pituitary injury due to massive hemorrhage. Traumatic injury resulting in hemorrhage in a non-pregnancy state can also cause partial or complete pituitary failure. Dahan's syndrome is pituitary injury due to severe vasospasm, without significant hemorrhage. Pituitary apoplexy is infarction of a pituitary adenoma and intra-mass hemorrhage with result injury to hormone production by the gland. Lymphocytic infiltration is the most common cause of hypophysitis and the mechanism is often unknown, although it may be autoimmune-related. The mechanism and treatments of each of these pathologies will be discussed in a context of reproduction.