Sheehans syndrome
Related Subjects:
| Prolactin
| Prolactinoma
| Sheehan's Syndrome
📖 About
- Sheehan's syndrome is a rare but important cause of hypopituitarism 👩🍼, resulting from ischaemic necrosis of the pituitary gland after severe postpartum haemorrhage.
- It differs from pituitary apoplexy, which is usually due to haemorrhage into a pituitary adenoma 🧠.
- Symptoms may present acutely (e.g. failure to lactate, amenorrhoea) or insidiously over years, making diagnosis delayed ⏳.
- Classic early clues: agalactia (failure to breastfeed) and secondary amenorrhoea soon after delivery.
🩸 Aetiology & Pathophysiology
- During pregnancy, the anterior pituitary enlarges (driven by lactotroph hyperplasia) but its blood supply does not increase proportionally ➝ vulnerable to hypoperfusion.
- Severe postpartum haemorrhage with hypovolaemia and hypotension leads to infarction of the anterior pituitary.
- Posterior lobe involvement is uncommon but may lead to diabetes insipidus 🚰.
🩺 Clinical Features
- Early: Failure to lactate (low prolactin), persistent amenorrhoea.
- Chronic: Fatigue, hypotension, weight loss, loss of libido, infertility.
- Adrenal insufficiency ➝ loss of pubic/axillary hair, hypotension.
- Thyroid axis deficiency ➝ cold intolerance, dry skin, bradycardia.
- Posterior pituitary involvement (rare): polyuria, polydipsia (diabetes insipidus).
- Up to 70% of anterior pituitary tissue may be destroyed before overt symptoms appear ⚠️.
🔬 Investigations
- Hormonal profile: ↓ TSH, ↓ Prolactin (unique), ↓ LH/FSH, ↓ GH, ↓ Cortisol (secondary adrenal insufficiency).
- MRI pituitary: empty sella or atrophic pituitary.
- Dynamic pituitary function tests can assess reserve (e.g. insulin tolerance test).
- Thyroid and adrenal tests confirm secondary endocrine deficiencies.
💊 Management
- Hormone replacement therapy tailored to deficits:
- Hydrocortisone for adrenal insufficiency (replace steroids before thyroid hormone!)
- Levothyroxine for hypothyroidism
- Sex steroid replacement (oestrogen/progesterone or testosterone) for hypogonadism
- Growth hormone in selected patients
- 💧 Desmopressin if diabetes insipidus is present.
- Ongoing follow-up with endocrine review; doses need to be adjusted in stress/illness.
- Education on “sick day rules” and the need to carry a steroid emergency card 💳.
📚 Key Points for Exams
- Postpartum woman + failure to lactate + amenorrhoea = think Sheehan’s 🧩.
- Low prolactin is highly suggestive (rare in other hypopituitarism).
- Differentiate from pituitary apoplexy (usually sudden headache, visual loss, adenoma background).
🔗 References
