Sheehan’s syndrome

DEFINITION

Sheehan’s syndrome is a condition that affects women who lose a life-threatening amount of blood or who have severe low blood pressure during or after childbirth. These factors can deprive your body of oxygen and can seriously damage vital tissues and organs. In the case of Sheehan’s syndrome, the damage occurs to the pituitary gland — a small gland at the base of your brain.

Sheehan’s syndrome causes the permanent underproduction of essential pituitary hormones (hypopituitarism). Also called postpartum hypopituitarism, Sheehan’s syndrome is rare in industrialized nations. But it’s still a major threat to women in developing countries.

Treatment of Sheehan’s syndrome involves hormone replacement therapy.

CAUSES

Although many problems can lead to low pituitary function, Sheehan’s syndrome is caused by severe blood loss or extremely low blood pressure during or after childbirth. These factors can be particularly damaging to the pituitary gland, destroying hormone-producing tissue so that the gland can’t function normally.

Pituitary hormones regulate the rest of your endocrine system, signaling other glands to increase or decrease production of the hormones that control metabolism, fertility, blood pressure, breast milk production and many other vital processes. A lack of any of these hormones can cause problems throughout your body — although signs and symptoms may develop so gradually that they escape notice.

Hormones that your pituitary secretes include:

• Growth hormone (GH). This hormone controls bone and tissue growth and maintains the right balance of muscle and fat tissue.
• Anti-diuretic hormone (ADH). By regulating urine production, this hormone manages water balance in your body. A deficiency of ADH results in excess urination and thirst, a condition called diabetes insipidus.
• Thyroid-stimulating hormone (TSH). This hormone stimulates your thyroid gland to produce key hormones that regulate your metabolism. Shortage of TSH results in an underactive thyroid gland (hypothyroidism).
• Luteinizing hormone (LH). In men, LH regulates testosterone production. In women, it fosters production of estrogen.
• Follicle-stimulating hormone (FSH). Working in tandem with LH, FSH helps stimulate sperm production in men and egg development and ovulation in women.
• Adrenocorticotropic hormone (ACTH). This hormone stimulates your adrenal glands to produce cortisol and other hormones. Cortisol helps your body deal with stress and influences many body functions, including blood pressure, heart function and your immune system. A low level of adrenal hormones caused by pituitary damage is called secondary adrenal insufficiency.
• Prolactin. This hormone regulates the development of female breasts, as well as the production of breast milk.

SYMPTOMS

Signs and symptoms of Sheehan’s syndrome typically appear slowly, after a period of months or even years. But sometimes — such as in a breast-feeding mother — problems may appear right away.

Signs and symptoms of Sheehan’s syndrome occur because of the deficiencies of the various hormones the pituitary gland controls: thyroid, adrenal, breast milk production and menstrual function. Signs and symptoms include:

• Difficulty breast-feeding or an inability to breast-feed
• No menstrual periods (amenorrhea) or infrequent menstruation (oligomenorrhea)
• Loss of pubic or underarm hair
• Slowed mental function, weight gain and difficulty staying warm as a result of an underactive thyroid (hypothyroidism)
• Low blood pressure
• Fatigue
• Irregular heartbeat
• Loss of interest in sex

For many women, Sheehan’s syndrome symptoms are nonspecific and often attributed to other things. Fatigue, for instance, goes hand in hand with being a new mother. You might not realize that you have Sheehan’s syndrome until you need treatment for thyroid or adrenal insufficiency.

It’s also possible to remain relatively symptom-free with Sheehan’s syndrome depending on the extent of damage to the pituitary gland. Some women live for years not knowing that their pituitary isn’t working properly. Then an extreme physical stressor, such as severe infection or surgery, triggers an adrenal crisis.