Correct Answer: B. Sheehan’s syndrome
Sheehan's syndrome is postpartum pituitary necrosis caused by severe hemorrhage during delivery, leading to hypovolemic shock and subsequent ischemic necrosis of the anterior pituitary. The clinical triad presented here—amenorrhoea, postpartum hemorrhage (PPH), and lactational failure—is pathognomonic. During pregnancy, the pituitary enlarges 2–3 fold due to lactotroph hyperplasia, increasing metabolic demands. When massive PPH occurs (>1000 mL), the resulting hypovolemia and hypotension cause selective necrosis of the anterior pituitary, sparing the posterior lobe (which has a separate blood supply). Loss of prolactin secretion explains lactational failure; loss of gonadotropins (FSH/LH) causes amenorrhoea. The syndrome is now rare in India due to improved obstetric care and blood transfusion availability, but remains a classic NEET PG question because it tests understanding of pituitary physiology, obstetric complications, and endocrine sequelae. The diagnosis is confirmed by low prolactin, low gonadotropins, and low cortisol on hormonal assay, with MRI showing pituitary atrophy or empty sella.
Why the other options are wrong
A. Acromegaly — Acromegaly is caused by excess growth hormone from a pituitary adenoma, presenting with gigantism, coarse features, and acanthosis nigricans—none of which fit this case. Acromegaly causes hyperprolactinemia (due to stalk compression), not lactational failure. The history of PPH and amenorrhoea following delivery is the discriminating clue that points to loss of pituitary function, not excess. NBE pairs pituitary disorders to test whether students confuse hyperfunction with hypofunction. C. Rotor syndrome — Rotor syndrome is a benign hereditary hyperbilirubinemia (autosomal recessive) affecting hepatic conjugation, presenting with jaundice and elevated conjugated bilirubin. It has no relationship to obstetric hemorrhage, amenorrhoea, or lactational failure. This is a classic distractor option—it tests whether students confuse rare syndromes by name alone. The 'syndrome' label in the question stem may lure students unfamiliar with Rotor's true pathophysiology. D. Prolactinoma — Prolactinoma causes elevated prolactin, leading to galactorrhoea and amenorrhoea, but NOT lactational failure (lactation would be present or excessive). Prolactinoma is not triggered by PPH and has no causal link to obstetric hemorrhage. While amenorrhoea is shared, the combination of PPH + lactational failure (not galactorrhoea) is the discriminating feature that excludes prolactinoma and points to pituitary necrosis with prolactin deficiency, not excess.
High-Yield Facts
- Sheehan's syndrome = postpartum pituitary necrosis from hypovolemic shock during massive PPH (>1000 mL); now rare in India due to improved obstetric care.
- Lactational failure is the hallmark sign—loss of prolactin secretion prevents milk production; amenorrhoea follows from gonadotropin deficiency.
- Anterior pituitary is selectively affected (posterior lobe spared due to separate blood supply); results in pan-hypopituitarism over time.
- Diagnosis confirmed by low prolactin, low FSH/LH, low cortisol, and MRI showing pituitary atrophy or empty sella.
- Clinical triad: postpartum hemorrhage + lactational failure + amenorrhoea = Sheehan's syndrome until proven otherwise.
Mnemonics
PPH → Pituitary Necrosis → Prolactin Loss PPH (Postpartum Hemorrhage) → PN (Pituitary Necrosis) → PL (Prolactin Loss). Massive bleeding → hypovolemic shock → anterior pituitary ischemia → loss of lactation. Use this when you see 'PPH + no lactation' in obstetric history. SHEEHAN = Shock + Hemorrhage + Empty sella + Endocrine loss + Amenorrhoea + Necrosis A mnemonic to recall the pathophysiology: Severe hemorrhage → Hypovolemic shock → Empty sella (pituitary atrophy) → Endocrine deficiency (prolactin, gonadotropins, ACTH, TSH) → Amenorrhoea + lactational failure → Necrosis of anterior pituitary.
NBE Trap
NBE pairs Sheehan's syndrome with prolactinoma because both cause amenorrhoea and involve prolactin; students who only recall "amenorrhoea + pituitary" may choose prolactinoma without noting the critical discriminator: lactational failure (not galactorrhoea) + postpartum hemorrhage history point exclusively to pituitary necrosis, not adenoma.
Clinical Pearl
In Indian obstetric practice, Sheehan's syndrome is now rare due to universal blood bank access and active management of third stage of labour (AMTSL), but it remains a bedside diagnosis in resource-limited settings where massive PPH goes untransfused. The absence of lactation in a woman who delivered vaginally is the red flag—normal lactation is expected unless pituitary function is lost.
_Reference: DC Dutta's Textbook of Obstetrics (7th ed.), Ch. 24 (Postpartum Hemorrhage & Complications); Harrison's Principles of Internal Medicine, Ch. 375 (Pituitary Disorders)_