This 32-year-old lady complains of persistent amenorrhea, despite stopping breastfeeding nine months ago. As menstruation usually recommences a month after ceasing lactation, this comes under the definition of secondary amenorrhea. In all patients with secondary amenorrhea, pregnancy must be excluded first. Here, this patients' urine hCG test is negative. The use of contraceptives, drugs, over-the-counter or herbal medications and illicit substances must also be considered, but her history is unremarkable in this regard. Given the history of hot flashes and diminished libido, an endocrinopathy is possible, with key differentials including hypogonadism, hypothyroidism, and hyperprolactinemia. As she has undergone obstetric procedures, structural causes (e.g. Asherman syndrome) should also be kept in mind. An endocrine profile and pelvic ultrasonography are good next steps. The latter shows a normal uterus with no adhesions, ruling out structural causes. Note also that the absence of follicular cysts suggests at ovarian dysfunction. However, the endocrine profile reveals partial panhypopituitarism, with low levels of gonadotropins, thyroid hormones, ACTH, and cortisol. When considered along with the history of severe postpartum hemorrhage, this suggests at Sheehan Syndrome (i.e. ischemic postpartum hypopituitarism). Subsequently, magnetic resonance imaging (MRI) of the pituitary shows the sella turcica to be partially empty, confirming the diagnosis. Note that there is little value in a GnRH stimulation test, as it is already patently clear that this is primary hypopituitarism. Her management revolves around the replacement of the deficient hormones. Note that glucocorticoids must be replaced before correcting the hypothyroidism. If not, an adrenal crisis may be precipitated. Furthermore, as she wishes to have a child in the future, hormone replacement therapy and referral to fertility services for ovulation induction is important, with many of these patients eventually becoming pregnant once more.
Sheehan syndrome (SS) is defined as postpartum hypopituitarism caused by necrosis of the pituitary gland. It is most often a complication of severe postpartum hemorrhage (PPH). SS is rare in the developed world due to comprehensive obstetric care. Even in developing countries, the incidence has been slowly declining over time, due to increased access to obstetric facilities. In pregnancy, the pituitary gland undergoes physiological enlargement and then compresses the superior hypophyseal artery. This renders the gland vulnerable to ischemic necrosis during the shock and/or severe hypotension engendered by PPH. SS is characterized by a variable spectrum of anterior pituitary dysfunction, with prolactin, cortisol, gonadotropins (FSH and LH), and thyroid stimulating hormone (TSH) being primarily involved. Less often, neurohypophyseal function may be impaired. Affected women may present during the postpartum period with lactational failure. Others only present months to years alter with amenorrhea and symptoms of anterior pituitary dysfunction. These include: - Adrenocortical insufficiency: orthostatic hypotension, easy fatigability, and hypopigmentation - Gonadotrophin deficiency: breast atrophy, low libido, and loss of hair in the genital and axillary regions - Hypothyroidism: weight gain, constipation, fatigue, and cold intolerance Rarely, patients may develop emergent manifestations, including severe circulatory collapse, adrenal crisis, congestive cardiac failure, or psychosis. Diabetes insipidus and hematological abnormalities such as anemia, pancytopenia, and acquired factor VIII or VW factor deficiency may also coexist. In patients in whom SS is suspected, a hormonal profile is mandatory, with low levels of anterior pituitary hormones suggesting the diagnosis. Computed tomography (CT) or magnetic resonance imaging (MRI) of the pituitary may reveal a partially or completely empty sella turcia. The main goal of treatment is to replace the various deficient hormones. Women who wish for a future pregnancy can be referred to fertility services for induction of ovulation. The overall prognosis depends on whether there is panhypopituitarism or if hormone production has been partially spared. Early diagnosis and comprehensive and systematic care are paramount to reducing morbidity and mortality.