A lady who was in her first pregnancy was admitted to the hospital for her delivery. Everything went well until the time the placenta, an organ that develops in a woman's womb (uterus) to nourish the baby during pregnancy, came out and bleeding was developed due to the absence of uterine contractions. Luckily, she was diagnosed earlier and treated by blocking the bleeding vessel in the operating room. She also got enough blood transfusions which helped her to get back to normal life and enjoy being a new mother. Unfortunately, her story didn’t end here. Around a week after she went back home, she suffered from seizures, which happen when the brain develops abnormal electrical activities. After a thorough and detailed exploration at the hospital, she was diagnosed with “Sheehan’s Syndrome”, a collection of hormonal changes in the body due to the lack of blood supply to the Pituitary gland.
Let’s begin with a brief explanation of the anatomy and physiology of the pituitary gland to understand the pathophysiology of Sheehan’s Syndrome. This pea-sized major endocrine gland lies at the base of the brain and its frontal part is responsible for the growth, development, and functioning of other endocrine glands such as adrenals, thyroid gland, ovaries and testicles. The hormonal signals such as CRH (Corticotropin-Releasing Hormone), TRH (Thyroid Releasing Hormone), GnRH (Gonadotropin-Releasing Hormone) which are created from another part of the brain, called the Hypothalamus, regulates other hormones to be secreted from the Pituitary gland, ACTH (Adrenocorticotropic Hormone), TSH (Thyroid Stimulating Hormone), and LH (Luteinizing Hormone) and FSH (Follicular Stimulating Hormone), respectively.
TRH also down-regulates the Prolactin hormone which is essential for a mother to produce milk for her baby. Those hormones then stimulate and cause changes in the peripheral secretory organs in the body. When the target organ has enough hormones to function, it sends signals to the Pituitary gland to stop sending more hormones. This same negative feedback regulation is also in place between the pituitary gland and the hypothalamus. Any disruption or malfunction in these systems causes clinical symptoms. One of the malfunctions of this system happens in the post-partum period- the time after a woman delivers her baby-when the pituitary gland does not have enough blood supply to create regulatory hormones and shrinks in the sella, the place where the gland sits in the brain. The sum of the clinical findings then is called Sheehan’s Syndrome.
The syndrome was first described by Glinski and Simmond in the beginning of 20th century as a severe anterior pituitary necrosis which is found in the biopsy results of a postpartum woman. They described the disease as a result of the postpartum hemorrhage and puerperal sepsis, which happened due to bacterial emboli or thrombosis in the vessels that water the pituitary area. In 1939, however, Harold Leeming Sheehan, a British physician and pathologist, described the disease as the necrosis of the anterior pituitary gland following the intensive blood loss after the delivery.
As mentioned, clinical findings mostly result from hormonal absence and those differ from woman to woman. Some examples are;
In the acute term headache, hypotension, visual impairment, failure of lactation due to blood loss,
Infertility, amenorrhea, absence or failure of the secretion of milk, breast atrophy, decreased libido due to Prolactin and Gonadotropin hormone deficiency,
Dry and sparse hair, pale skin, constipation, cold intolerance, mental slowing due to thyroid hormone deficiency,
Loss of pigmentation of the skin, fatigue, hypotension due to cortisol deficiency, Impaired quality of life and body composition differences due to the lack of growth hormone effects,
Psychiatric disturbances
Diagnosis requires high suspicion and knowledge of the disease. In the developed part of the world, disease prevalence has decreased significantly due to advancement of fast recognition and treatment. However, Sheehan’s Syndrome still can be seen in developing and underdeveloped countries and causes morbidity and mortality among women. Some women show vague symptoms such as fatigue and postpartum blues that result in a delay for the diagnosis and treatment. Definitive diagnosis is made by seeing the ‘empty sella’, the necrotic finding of the pituitary gland in the radiological studies such as CT and MRI along with the support of the laboratory tests of decreased hormones.
Treatment requires adequate fluid and blood transfusion in the acute term. In the long-term, when hypopituitarism is developed, thyroid and glucocorticoid replacement should be done immediately to protect the hypothalamic–pituitary–adrenal axis.What happened to our case later on? Well, her laboratory test results showed a lack of thyroid and prolactin hormone levels, and adrenal insufficiency along with hypoglycemia. She was given thyroxine and hydrocortisone and was discharged from the hospital with improvement of her symptoms. She developed infertility later on and was able to conceive with induction of ovulation, a method used to stimulate ovaries to produce eggs.