Alternative names for Sheehan’s syndrome
Postpartum pituitary necrosis; postpartum panhypopituitarism
What is Sheehan’s syndrome?
Sheehan’s syndrome is a condition in which severe bleeding or extremely low blood pressure during or immediately after childbirth causes damage to the pituitary gland. The damage to pituitary tissue from lack of oxygen may result in pituitary hormone deficiencies (hypopituitarism) requiring lifelong hormone replacement.
What causes Sheehan’s syndrome?
During pregnancy, an increased amount of the hormone oestrogen in the body causes an increase in the size of the pituitary gland and the volume of blood flowing through it. This makes the pituitary gland more vulnerable to damage from loss of blood and subsequent lack of oxygen. If heavy bleeding occurs during or immediately after childbirth, there will be a sudden decrease in the blood supply to the already vulnerable pituitary gland. This can cause tissue death and subsequent loss of pituitary function.
Usually only the anterior (front) part of the pituitary gland is affected. The following hormones are released from the anterior pituitary and may be deficient in patients with Sheehan’s syndrome:
- adrenocorticotropic hormone ACTH (stimulates the adrenal glands to secrete steroid hormones such as cortisol)
- growth hormone GH (regulates growth, metabolism and body composition)
- luteinising hormone (LH) and follicle stimulating hormone (FSH) (also known as the gonadotrophins) these act on the ovaries to stimulate sex hormone production (estrogen) and ovulation
- prolactin (stimulates milk production)
- thyroid stimulating hormone TSH (stimulates the thyroid gland to secrete thyroid hormones).
What are the signs and symptoms of Sheehan’s syndrome?
In some women, Sheehan’s syndrome may cause very few, if any, symptoms. These symptoms may be non-specific and may not be diagnosed unless specifically tested for. Most symptoms will not be apparent straight away and may take months or even years to develop. Most commonly, women have difficulty with or are not able to breastfeed (due to lack of prolactin) and have infrequent or no periods after childbirth (due to lack of gonadotrophins). The patient may also feel tired and experience weight gain (due to lack of thyroid hormones), loss of pubic or underarm hair, decrease or absent menstrual cycles and infertility (due to lack of sex hormones) and have low blood pressure, dizziness and extreme fatigue (due to lack of adrenocorticotropic hormone and subsequently cortisol).
How common is Sheehan’s syndrome?
Sheehan’s syndrome is rare in developed countries where improved maternal care usually prevents extreme blood loss during delivery. The condition is still common in developing countries where women may still bleed heavily during childbirth.
Is Sheehan’s syndrome inherited?
No, Sheehan’s syndrome is not inherited; it is related exclusively to pregnancy.
How is Sheehan’s syndrome diagnosed?
The diagnosis of Sheehan’s syndrome will partly be based on the patient’s medical history; in particular, whether any blood loss during delivery occurred, or any other complications relating to childbirth. It is also important to assess whether there were difficulties with breastfeeding or a lack of periods after delivery, which are two important signs of Sheehan’s syndrome.
Blood tests will be carried out to check pituitary hormone levels. A simple blood test may be sufficient or a more detailed type of testing called ‘dynamic’ testing may be carried out. This type of testing involves checking hormone levels before and after stimulation of the pituitary gland to assess how the pituitary is functioning.
Scans such as computerised tomography (CT) or magnetic resonance imaging (MRI) may also be carried out to investigate the size and structure of the pituitary gland.
How is Sheehan’s syndrome treated?
Once the diagnosis of Sheehan’s syndrome is confirmed, the treatment is lifelong replacement of the hormones that are found to be deficient. This may take the form of hydrocortisone, thyroxine, oestrogen and rarely, growth hormone. The exact form of treatment will vary between patients depending on the hormones that need to be replaced. See the article on hypopituitarism for more information.
Are there any side-effects to the treatment?
If blood levels of hormones are monitored carefully, there should not be any side-effects. Side-effects may rarely occur when the dosage of hormone treatment is too high or too low and should be easily corrected by dose adjustment of the relevant medication. Patients should discuss any concerns with their doctor.
What are the longer-term implications of Sheehan’s syndrome?
Hormone treatment is usually long-term and patients will require regular check-ups with their doctor. If the patient is on steroids, they must be aware of sick day rules and have an emergency hydrocortisone injection, which they and their family know how to use. They should also wear Medic-Alert jewellery (usually necklace or bracelet) and carry a steroid card in their wallet stating that they are on steroid medication. See the articles on Addison’s disease and hypopituitarism for further information.