Pregnancy, Childbirth & Puerperium

Sheehan syndrome: postpartum pituitary failure

Clinical Overview and When to Suspect Sheehan Syndrome

— The gravid pituitary is physiologically enlarged (lactotroph hyperplasia) and outgrows its blood supply, making it uniquely vulnerable to hypoperfusion.

— Posterior pituitary is usually spared (separate inferior hypophyseal artery supply); central diabetes insipidus is uncommon but possible.

— Acute (days–weeks postpartum): Failure to lactate, persistent hypotension, hypoglycemia, hyponatremia, or adrenal crisis after a complicated delivery.

— Chronic (months–years later): Secondary amenorrhea, loss of axillary/pubic hair, cold intolerance, fatigue, weight loss, hypotension. Often diagnosed 5–20 years after the index pregnancy.

Definition: Postpartum hypopituitarism caused by ischemic necrosis of the anterior pituitary, classically precipitated by severe peripartum hemorrhage with hypotension/shock.

Epidemiology: Now rare in resource-rich settings due to improved obstetric hemorrhage management; remains common in low-resource settings where home/unattended deliveries predominate. Suspect in any woman with prior obstetric hemorrhage plus unexplained fatigue, amenorrhea, or hyponatremia.

When to suspect (Step 3 framing):

Pathophysiology pearl: Anterior pituitary hormones are lost in a roughly predictable order — GH and prolactin first (most vulnerable somatotrophs/lactotrophs), followed by gonadotropins (LH/FSH), then TSH and ACTH. Failure to lactate is therefore the earliest and most specific clue.

Board pearl: Any postpartum woman who cannot breastfeed AND fails to resume menses after a delivery complicated by hemorrhage has Sheehan syndrome until proven otherwise — do not chalk it up to "postpartum fatigue."

Step 3 management: In a stable outpatient, the workup is staged hormonal testing; in an unstable patient with hypotension/hypoglycemia postpartum, treat empirically with stress-dose hydrocortisone FIRST, then investigate. Never delay glucocorticoids waiting for labs in suspected adrenal crisis.

Presentation Patterns and Key History

— Acute Sheehan (uncommon, dramatic): Within days of delivery — hypotension unresponsive to fluids, hypoglycemia, hyponatremia, lethargy, failure to lactate. Mimics septic shock or pulmonary embolism.

— Chronic Sheehan (typical board stem): Insidious, often years later — agalactia after delivery, never resumed menses, progressive fatigue, cold intolerance, weight loss, decreased libido, loss of body hair, dry skin, hypotension.

— Obstetric hemorrhage (uterine atony, placenta previa/accreta, retained products, DIC, abruption) requiring transfusion or causing hypotension.

— Failure to lactate postpartum (prolactin deficiency) — earliest sign.

— Failure to resume menses (gonadotropin deficiency) — second earliest.

— Loss of axillary and pubic hair (combined gonadotropin + adrenal androgen loss).

— Lactotroph (PRL): immediate failure to nurse.

— Gonadotroph (LH/FSH): persistent amenorrhea, infertility, vaginal atrophy, dyspareunia.

— Thyrotroph (TSH): cold intolerance, constipation, dry skin, bradycardia, weight gain — develops over months.

— Corticotroph (ACTH): orthostasis, fatigue, anorexia, nausea, hypoglycemia, hyponatremia — most dangerous.

— Somatotroph (GH): decreased lean mass, central adiposity, dyslipidemia, low quality of life — often subclinical.

Two dominant clinical phenotypes:

Cardinal historical features to anchor the diagnosis:

Symptom timeline by hormonal axis:

Key distinction: Unlike primary Addison disease, Sheehan causes secondary adrenal insufficiency — so no hyperpigmentation (low ACTH) and no hyperkalemia (aldosterone is intact via renin-angiotensin). Hyponatremia is present, but it is dilutional/SIADH-like from cortisol deficiency, not from mineralocorticoid loss.

Board pearl: A multiparous woman presenting years later with fatigue, hypothyroid features, and amenorrhea — always ask about peripartum bleeding and breastfeeding history. This single question converts a vague stem into Sheehan syndrome.

Step 3 management: Document parity, delivery complications, transfusion requirement, and lactation/menstrual history in every adult woman with unexplained panhypopituitarism.

Physical Exam Findings and Hemodynamic Assessment

— Hypotension (often orthostatic) — combined cortisol and thyroid deficiency.

— Bradycardia — central hypothyroidism.

— Hypothermia — central hypothyroidism, advanced cases.

— Normal to low respiratory rate; tachycardia only if volume-depleted or in crisis.

— Pallor (anemia of chronic disease, hypothyroidism, possible concurrent iron deficiency).

— Dry, cool, coarse skin; nonpitting periorbital edema (myxedema).

— Loss of axillary and pubic hair; sparse eyebrows (lateral thinning).

— No hyperpigmentation (distinguishes from primary adrenal insufficiency).

— Breast atrophy; vaginal/vulvar atrophy on GU exam.

— Delayed relaxation of deep tendon reflexes (hung-up reflexes) from hypothyroidism.

— Mental slowing, depression, occasionally psychosis ("myxedema madness") in severe cases.

— Visual fields typically normal (unlike pituitary macroadenoma — no chiasmal compression).

— Hypotension refractory to IV fluids and vasopressors is the red flag for adrenal crisis.

— Hypoglycemia (cortisol + GH deficiency) and hyponatremia (cortisol deficiency → impaired free water excretion) are reliable laboratory companions of physical findings.

General appearance: Thin, pale, fatigued-appearing woman; "doll-like" facies described classically; fine wrinkling around mouth/eyes from estrogen deficiency.

Vital signs:

Skin and adnexa:

Neurologic:

Hemodynamic assessment in acute presentation:

Key distinction: Sheehan exam ≈ Addison exam minus hyperpigmentation and minus hyperkalemia. Add features of central hypothyroidism and hypogonadism on top. If you see hyperpigmented palmar creases or buccal mucosa, rethink toward primary adrenal failure.

Board pearl: Postural drop >20 mmHg systolic in a young postpartum or formerly postpartum woman with fatigue should trigger an 8 AM cortisol — do not stop at "deconditioning."

Step 3 management: In the office, document orthostatics, weight trend, and a focused exam for hypothyroid stigmata and hair distribution before ordering hormonal panels — physical findings narrow the differential and justify the lab cascade.

Diagnostic Workup — Initial Labs

— 8 AM serum cortisol + simultaneous ACTH: cortisol <3 µg/dL is diagnostic of adrenal insufficiency; with low or inappropriately normal ACTH → secondary (pituitary) cause.

— Free T4 + TSH: low free T4 with low or inappropriately normal TSH → central hypothyroidism (the giveaway pattern).

— LH, FSH, estradiol: low estradiol with low/normal LH and FSH → secondary hypogonadism.

— Prolactin: low or low-normal (lactotroph destruction). In contrast, stalk-effect lesions raise prolactin — useful differentiator.

— IGF-1: low, suggests GH deficiency (confirm with stimulation testing).

— Hyponatremia (dilutional, from cortisol deficiency reducing free water clearance and from hypothyroidism).

— Hypoglycemia (cortisol + GH deficiency).

— Normal potassium (aldosterone preserved) — separates from Addison disease.

— Normocytic anemia common; macrocytic anemia with hypothyroidism.

— Mild eosinophilia possible (cortisol deficiency).

Order the hormonal panel as paired central/peripheral values — interpreting peripheral hormone without its trophic hormone is the classic Step 3 trap.

Initial labs (basic metabolic + hormonal screen):

Metabolic and hematologic clues:

Pregnancy/postpartum-specific: Check β-hCG in any reproductive-age woman with amenorrhea before attributing to Sheehan; a new pregnancy can rarely occur if residual gonadotropin function exists.

Key distinction: Low TSH + low free T4 = central hypothyroidism (think pituitary). High TSH + low free T4 = primary hypothyroidism (Hashimoto's, postpartum thyroiditis). Postpartum thyroiditis is a frequent foil on boards — different mechanism, different management.

Board pearl: A low or low-normal TSH with a low free T4 is one of the highest-yield findings on Step 3 — it should immediately push you to evaluate the entire anterior pituitary axis, not just the thyroid.

Step 3 management: Bundle the hormonal panel into a single AM blood draw to avoid serial visits; obtain MRI only after biochemical confirmation unless mass effect signs are present.

Diagnostic Workup — Advanced and Confirmatory Studies

— Cosyntropin (ACTH) stimulation test: 250 µg IV/IM, measure cortisol at 30 and 60 min. Peak cortisol <18 µg/dL is abnormal. In long-standing secondary adrenal insufficiency, adrenal atrophy yields a blunted response — so this test works for chronic Sheehan but can be falsely normal in acute secondary AI (adrenals not yet atrophied). In acute cases, use insulin tolerance test or metyrapone test.

— Insulin tolerance test (ITT): Gold standard for both ACTH and GH axes. Induce hypoglycemia (<40 mg/dL); cortisol should rise >18 and GH >5 ng/mL. Contraindicated in elderly, seizure disorder, CAD.

— GHRH-arginine or glucagon stimulation for GH axis if ITT contraindicated.

— GnRH stimulation rarely needed; basal low LH/FSH with low estradiol in amenorrheic woman suffices.

— Acute Sheehan: pituitary enlargement with central non-enhancement (ischemic necrosis).

— Chronic Sheehan: empty sella (CSF-filled sella turcica from atrophied gland) — classic finding.

— Rules out mass lesions (macroadenoma, craniopharyngioma, metastasis), lymphocytic hypophysitis, and apoplexy.

— Bone densitometry (DEXA) — chronic estrogen and GH deficiency cause osteoporosis.

— Lipid panel, A1c — central adiposity and dyslipidemia from GH deficiency.

— Antipituitary antibodies if lymphocytic hypophysitis is suspected (also postpartum, often without hemorrhage history).

Dynamic (stimulation) testing — used when basal labs are equivocal:

Neuroimaging — pituitary MRI with contrast:

Additional confirmatory considerations:

Key distinction: Lymphocytic hypophysitis vs Sheehan: hypophysitis shows pituitary enlargement with homogeneous enhancement and stalk thickening on MRI, often with headache and visual changes, and ACTH axis is preferentially affected first — opposite of Sheehan's lactotroph-first pattern.

Board pearl: Empty sella + history of postpartum hemorrhage + panhypopituitarism = Sheehan syndrome. This triad is a near-pathognomonic Step 3 vignette.

Step 3 management: Reserve ITT for endocrinology referral; in primary care, basal labs + cosyntropin test + MRI are sufficient to confirm and stage the disorder.

Risk Stratification and First-Line Management Logic

— Adrenal crisis / acute Sheehan (hypotension, hypoglycemia, hyponatremia, altered mentation): emergency — IV hydrocortisone, IV fluids, glucose, ICU/step-down admission.

— Symptomatic chronic Sheehan (fatigue, amenorrhea, cold intolerance): outpatient hormone replacement, endocrinology referral.

— Asymptomatic biochemical Sheehan (incidental low free T4 with low TSH in a woman with PPH history): still treat — pituitary deficits do not self-resolve.

— Glucocorticoid FIRST, then levothyroxine second. Starting thyroid hormone before cortisol can precipitate adrenal crisis by increasing metabolic clearance of residual cortisol.

— Sex steroids and GH are added later for symptomatic and long-term benefit.

— Delayed diagnosis (>10 years) — irreversible osteoporosis, cardiovascular risk accrual.

— Pregnancy desired — requires specialty fertility intervention.

— Comorbid cardiovascular disease — limits aggressive thyroid replacement initiation.

— Replacement is lifelong.

— Doses are titrated to symptoms and free T4 (not TSH, which is unreliable in central hypothyroidism).

— Stress-dose steroid education is mandatory at the first visit — this is the single most important patient safety intervention.

Triage by acuity:

Order of hormone replacement (critical sequence):

Risk factors that worsen prognosis:

General principles:

Key distinction: In primary hypothyroidism you titrate levothyroxine to TSH. In central (Sheehan) hypothyroidism, TSH is uninformative — titrate to free T4 in the mid-to-upper normal range and symptom resolution. Missing this is a common Step 3 trap.

CCS pearl: For an acutely presenting postpartum woman, the CCS order set is: IV access → fingerstick glucose → stat cortisol/ACTH/TSH/free T4 → IV hydrocortisone 100 mg → normal saline bolus → D5NS infusion → ICU admit → endocrine consult. Levothyroxine is added only after steroids are on board.

Step 3 management: Recognize that "treat suspected before confirmed" is acceptable and expected in adrenal crisis — the cosyntropin stim can be done after stabilization.

Pharmacotherapy — First-Line Hormone Replacement

— Hydrocortisone 15–25 mg/day divided (e.g., 10 mg AM, 5 mg early afternoon, 5 mg late afternoon) — mimics diurnal rhythm.

— Alternative: prednisone 3–5 mg daily for compliance, but less physiologic.

— Mineralocorticoid (fludrocortisone) NOT needed — aldosterone is preserved in secondary AI.

— Stress dosing: Double or triple the daily dose for febrile illness, minor surgery; 100 mg IV q8h for major surgery, trauma, or sepsis. Patient must carry an emergency injection kit and medical alert ID.

— Levothyroxine 1.6 µg/kg/day in healthy adults; start lower (25–50 µg) in elderly or cardiac disease.

— Titrate to free T4 in upper half of normal range; recheck 6–8 weeks after dose change.

— Do not follow TSH — it is suppressed/inappropriate in central disease.

— Estrogen + progestin (cyclic or continuous) in premenopausal women until age ~50 — prevents osteoporosis, vaginal atrophy, dyspareunia.

— Estrogen-only if hysterectomy. Discontinue at natural menopausal age and reassess risk/benefit.

— Transdermal estradiol preferred if VTE risk factors.

— Recombinant somatropin SC daily for documented GH deficiency on stimulation testing — improves body composition, lipids, bone density, quality of life.

— Contraindicated in active malignancy, proliferative retinopathy, severe critical illness.

— Monitor IGF-1 to mid-normal range.

— Pulsatile GnRH or exogenous FSH + LH (gonadotropins) with hCG trigger — refer to reproductive endocrinology.

Glucocorticoid replacement (priority #1):

Thyroid replacement (start AFTER cortisol):

Sex hormone replacement:

Growth hormone replacement:

Fertility induction (if pregnancy desired):

Board pearl: Cortisol before thyroxine, always. Reversing this order has precipitated fatal adrenal crises and is a favorite USMLE distractor.

Step 3 management: At every refill visit, verbally confirm the patient understands sick-day rules — this is a measurable, board-tested patient safety counseling point.

Expanded Pharmacology and Special Scenarios

— Minor stress (URI, dental work, low-grade fever): double oral dose for 2–3 days, then resume baseline.

— Moderate stress (gastroenteritis with vomiting, minor surgery): IM/IV hydrocortisone 50 mg, then 25 mg q6–8h × 24 h.

— Major stress (major surgery, trauma, sepsis, labor): hydrocortisone 100 mg IV bolus, then 50–100 mg IV q6–8h or continuous infusion 200 mg/24 h; taper over 2–3 days as clinically tolerated.

— Patient must have IM hydrocortisone (Solu-Cortef Act-O-Vial) or dexamethasone at home for vomiting/inability to take PO.

— Enzyme inducers (rifampin, phenytoin, carbamazepine, St. John's wort) accelerate cortisol metabolism — increase hydrocortisone dose.

— Estrogen increases thyroxine-binding globulin → may require higher levothyroxine dose.

— Calcium, iron, PPIs, bile acid sequestrants reduce levothyroxine absorption — separate by 4 hours.

— Take on empty stomach, 30–60 min before breakfast (or at bedtime ≥3 h after dinner).

— Generic-to-brand switching can alter levels — recheck free T4 after any formulation change.

— Free T4 at 6–8 weeks after any thyroid dose change, then annually.

— IGF-1 every 6 months on GH therapy.

— DEXA every 2 years.

— Lipids and A1c annually.

Stress-dose steroid algorithm (memorize):

Drug-drug interactions to flag:

Levothyroxine administration pearls:

Monitoring labs cadence:

Key distinction: Vasopressin/desmopressin is not routinely required — posterior pituitary is usually spared. If polyuria/polydipsia develops, formally test for central diabetes insipidus (water deprivation test) before assuming.

Board pearl: A Sheehan patient hospitalized for any acute illness who does not receive stress-dose steroids is a sentinel safety event. Always check the med rec on admission.

Step 3 management: Provide written sick-day rules, an emergency hydrocortisone injection kit, and a MedicAlert bracelet at the diagnostic visit — these are testable transition-of-care interventions.

Special Populations — Elderly and Renal/Hepatic Impairment

— Initiate levothyroxine cautiously — start 12.5–25 µg/day and uptitrate every 4–6 weeks; rapid replacement can precipitate angina, atrial fibrillation, or MI.

— Screen for CAD before initiating thyroid replacement if anginal symptoms or known risk; consider stress testing.

— Hydrocortisone dose may be lower (10–15 mg/day) due to reduced lean mass and slower metabolism.

— Estrogen replacement generally not initiated after age 60 due to elevated cardiovascular and breast cancer risk — focus on bone protection with bisphosphonates and vitamin D/calcium.

— GH replacement is more controversial in elderly; assess functional benefit vs cost and malignancy risk.

— Hydrocortisone and levothyroxine doses are largely unchanged in CKD.

— Hyponatremia may be multifactorial — distinguish cortisol-deficiency hyponatremia from CKD-related volume issues.

— Avoid NSAIDs (common analgesic choice in elderly) — worsen renal function and gastric tolerability of oral steroids.

— Hydrocortisone is activated by 11β-HSD; in severe hepatic dysfunction, prednisolone (already active) is preferred over prednisone.

— Levothyroxine metabolism slows — monitor free T4 more frequently.

— Estrogen contraindicated in active liver disease.

— Cross-check for PPIs, calcium, iron — impair levothyroxine absorption.

— Cross-check for anticoagulants — thyroid replacement potentiates warfarin (recheck INR).

— Cross-check for antihypertensives — euthyroid state may unmask need for dose adjustment.

Elderly patients with delayed-diagnosis Sheehan:

Renal impairment:

Hepatic impairment:

Polypharmacy review:

Key distinction: Elderly Sheehan patients are at higher risk for fracture, cardiovascular events, and steroid-induced delirium than younger patients — set replacement targets to the lower end of normal ranges.

Board pearl: Any elderly woman with osteoporosis, hyponatremia, and a remote history of "difficult childbirth decades ago" deserves a pituitary workup before being labeled "frail."

Step 3 management: In a frail elderly patient, prioritize fall prevention, bone health, and stress-dose education over aggressive normalization of every hormone axis.

Special Populations — Pregnancy and Subsequent Fertility

— Spontaneous pregnancy is rare but documented in partial Sheehan.

— Most require ovulation induction with exogenous gonadotropins (FSH + LH) or pulsatile GnRH; refer to reproductive endocrinology preconception.

— Counsel on increased risks: miscarriage, preterm delivery, IUGR, and recurrence of adrenal crisis peripartum.

— Increase levothyroxine by ~30% as soon as pregnancy is confirmed (mirroring primary hypothyroid pregnancy management); titrate to free T4 in upper-normal trimester-specific range. TSH remains uninformative.

— Continue baseline hydrocortisone; physiologic cortisol-binding globulin rises in pregnancy may require a modest dose increase in third trimester.

— Estrogen/progestin discontinued (pregnancy itself provides).

— GH replacement typically held during pregnancy.

— Stress-dose hydrocortisone: 100 mg IV at onset of active labor, then 50 mg IV q6h until 24–48 h postpartum; taper to baseline over 2–3 days.

— Continuous fetal monitoring; anticipate possible recurrent postpartum hemorrhage.

— Anesthesia team aware of adrenal insufficiency — avoid etomidate.

— Re-screen pituitary axis at 6 weeks — pregnancy may unmask or worsen deficits.

— Lactation is typically impossible due to lactotroph destruction; counsel preemptively and arrange formula support without guilt-laden framing.

Subsequent pregnancy in a Sheehan patient — feasible with assistance:

Antepartum management:

Intrapartum (labor and delivery):

Postpartum:

Pediatrics: Sheehan is by definition a postpartum maternal disease; children of affected mothers have no inherent risk. Pediatric hypopituitarism has distinct etiologies (congenital, craniopharyngioma, trauma, irradiation).

Key distinction: Lymphocytic hypophysitis (autoimmune) often presents during or shortly after pregnancy with headache and visual changes — overlapping demographic but distinct MRI and treatment (glucocorticoids high-dose for inflammation, sometimes transsphenoidal surgery).

Board pearl: Failure to lactate after a hemorrhagic delivery is Sheehan until proven otherwise; failure to lactate after an uncomplicated delivery with headache and bitemporal hemianopia is lymphocytic hypophysitis.

Step 3 management: Co-manage subsequent pregnancies with MFM and endocrinology from preconception through 6-week postpartum visit.

Complications and Adverse Outcomes

— Adrenal crisis: Hypotension refractory to fluids/pressors, hypoglycemia, hyponatremia, altered mental status. Mortality without treatment approaches 100%. Precipitants include infection, surgery, trauma, missed steroid doses, GI illness with vomiting.

— Myxedema coma: Hypothermia, bradycardia, hypoventilation, hyponatremia, stupor. Mortality 20–40% even with treatment. Treat with IV levothyroxine + IV hydrocortisone simultaneously (cortisol first if any doubt about adrenal axis).

— Severe hyponatremia: Seizures, cerebral edema. Correct cautiously to avoid osmotic demyelination.

— Hypoglycemia: Especially in neonates of affected mothers and in fasting adults; cortisol + GH deficiency synergize.

— Osteoporosis and fragility fractures — from estrogen, GH, and possibly over-replacement of cortisol/thyroid.

— Cardiovascular disease — dyslipidemia, increased visceral fat, endothelial dysfunction from GH deficiency; increased all-cause mortality if untreated.

— Infertility — gonadotropin deficiency; reversible with ART.

— Cognitive and mood disorders — depression, decreased quality of life; partially reversible with replacement.

— Anemia — multifactorial; usually improves with thyroid and cortisol replacement.

— Steroid over-replacement → Cushingoid features, weight gain, hypertension, diabetes, osteoporosis, immunosuppression. Audit dose annually.

— Levothyroxine over-replacement → atrial fibrillation, bone loss, anxiety, weight loss.

— Estrogen-related VTE — use transdermal in higher-risk patients.

Acute, life-threatening:

Chronic complications:

Iatrogenic complications:

Key distinction: Adrenal crisis in Sheehan presents without hyperpigmentation and without hyperkalemia — easy to miss if the clinician is anchored on the classic Addisonian picture.

Board pearl: A Sheehan patient on chronic steroids who develops nausea, vomiting, and hypotension during gastroenteritis is in adrenal crisis until proven otherwise — give IM/IV hydrocortisone before any further workup.

Step 3 management: Document complications inventory at annual visit: BMD, lipids, A1c, mood screen, fracture history — this drives the prevention plan.

When to Escalate Care — ICU, Consult, Inpatient Triage

— Hypotension with altered mental status or hypoglycemia.

— Vomiting precluding oral steroid intake.

— Suspected sepsis or major trauma in a known Sheehan patient.

— Seizure or focal neuro deficit (consider hyponatremia, hypoglycemia, apoplexy).

— Adrenal crisis requiring vasopressors or continuous hydrocortisone infusion.

— Myxedema coma — airway management, passive rewarming, IV thyroxine/triiodothyronine.

— Severe symptomatic hyponatremia (<120 mEq/L with seizures or coma).

— Hemodynamic instability of any cause in a steroid-dependent patient.

— Moderate adrenal insufficiency symptoms responsive to IV hydrocortisone but unable to tolerate PO.

— New diagnosis of Sheehan with multiple axis failures requiring monitored initiation.

— Failure-to-thrive postpartum mother for stabilization and feeding plan.

— Endocrinology — at diagnosis and at least annually thereafter.

— OB/Gyn / Reproductive endocrinology — for fertility, HRT in young women, subsequent pregnancy.

— Neurosurgery — only if MRI shows mass lesion or apoplexy.

— Psychiatry — for depression, adjustment to chronic illness.

— Social work — for medication access, emergency-injection training, MedicAlert procurement.

— Always communicate stress-dose plan to anesthesia preoperatively.

— Medication reconciliation must explicitly list hydrocortisone with stress-dose instructions, not just "steroid replacement."

— Discharge summary should include emergency injection kit refill date.

Indications for emergency department / 911 transfer:

Indications for ICU admission:

Inpatient (non-ICU) admission criteria:

Consultations:

Transition of care priorities:

Key distinction: A Sheehan patient with severe hyponatremia who has been chronically hyponatremic must be corrected slowly (<8 mEq/L/24 h) to avoid osmotic demyelination, even if symptomatic.

CCS pearl: In CCS adrenal crisis: location move to ICU, vitals q1h, IV hydrocortisone, NS bolus then D5NS, finger-stick glucose q1h, cortisol/ACTH (drawn before steroid if not delayed), search for precipitant (CXR, UA, blood cultures), endocrine consult.

Step 3 management: Escalate early and document the rationale — undertriage of a Sheehan patient is a frequent malpractice scenario.

Key Differentials — Same-Category (Pituitary/Hypothalamic) Causes

— Autoimmune, often peripartum, classically affects ACTH first, then TSH, then gonadotrophs.

— MRI: symmetric pituitary enlargement with homogeneous enhancement, thickened stalk.

— Headache and visual field defects common.

— May respond to high-dose glucocorticoids; sometimes resolves spontaneously.

— Acute hemorrhage or infarction into a pre-existing adenoma.

— Sudden severe headache, ophthalmoplegia, visual loss, altered mentation.

— MRI: hemorrhagic mass; can mimic acute Sheehan but typically with mass effect.

— Surgical decompression often needed.

— Insidious panhypopituitarism with mass effect (bitemporal hemianopia, headache).

— Prolactin elevated (prolactinoma or stalk effect) — opposite of Sheehan.

— Suprasellar mass; calcifications on imaging; bimodal age (children and adults).

— Often produces diabetes insipidus (posterior pituitary involvement) — uncommon in Sheehan.

— Often incidental, asymptomatic, normal pituitary function.

— Distinguish from Sheehan-related empty sella by absence of hormonal deficits and absence of PPH history.

— Tumors, infiltrative (sarcoidosis, Langerhans cell histiocytosis, hemochromatosis), or post-radiation.

— TRH and CRH testing helps localize hypothalamic vs pituitary, but rarely needed clinically.

— History gives it away; can develop months to years after insult.

Lymphocytic hypophysitis:

Pituitary apoplexy:

Pituitary macroadenoma (non-functioning or prolactinoma):

Craniopharyngioma / Rathke cleft cyst:

Empty sella syndrome (primary):

Hypothalamic dysfunction:

Traumatic brain injury / post-radiation hypopituitarism:

Key distinction: Sheehan = anterior pituitary infarction from PPH, lactotroph-first, low prolactin, empty sella. Hypophysitis = autoimmune inflammation, ACTH-first, enlarged enhancing gland. Apoplexy = sudden bleed into adenoma, surgical emergency.

Board pearl: Prolactin level is the single most useful differentiator — low in Sheehan, high in stalk-effect lesions and prolactinomas, normal-to-high in hypophysitis.

Step 3 management: MRI is the discriminator — order it after biochemical confirmation, not as the initial screen.

Key Differentials — Other-Category Causes

— Autoimmune most common in US; TB worldwide.

— Hyperpigmentation, hyperkalemia, low aldosterone, high ACTH — opposite biochemical pattern from Sheehan.

— Requires both glucocorticoid and mineralocorticoid (fludrocortisone) replacement.

— High TSH, low free T4; positive anti-TPO antibodies in Hashimoto's.

— Postpartum thyroiditis: triphasic (hyperthyroid → hypothyroid → euthyroid); usually transient.

— Distinguished by TSH pattern alone.

— Amenorrhea with high FSH/LH and low estradiol (primary gonadal failure).

— In Sheehan, gonadotropins are low — secondary hypogonadism.

— Hypothalamic amenorrhea (eating disorder, athletic, stress) gives low LH/FSH/estradiol — overlap with Sheehan, but no other axis deficits and no PPH history.

— Overlap with vague Sheehan symptoms. Hormonal panel rules in or out.

— Common in postpartum women; can coexist with Sheehan; do not stop at anemia diagnosis if symptoms persist after correction.

— Fatigue and dyspnea in a postpartum woman — echocardiography clarifies.

— Postpartum endometritis or sepsis can mimic acute Sheehan. Always pursue infectious workup in parallel.

— Episodic hypertension/hypotension; metanephrines distinguish.

Primary adrenal insufficiency (Addison disease):

Primary hypothyroidism (Hashimoto's, postpartum thyroiditis):

Premature ovarian insufficiency:

Polycystic ovary syndrome / hypothalamic amenorrhea:

Depression / chronic fatigue syndrome / fibromyalgia:

Anemia (iron deficiency, B12 deficiency):

Postpartum cardiomyopathy:

Sepsis / occult infection:

Pheochromocytoma (rare):

Key distinction: High ACTH + low cortisol = primary (Addison). Low/normal ACTH + low cortisol = secondary (Sheehan / pituitary). Memorize this paired interpretation — it is tested every cycle.

Board pearl: Combined deficits across multiple endocrine axes strongly favor a pituitary-level lesion; isolated axis failure favors end-organ disease.

Step 3 management: Use the paired hormone (trophic + peripheral) approach to localize the lesion before ordering imaging — this is both cost-effective and board-correct.

Secondary Prevention, Discharge Medications, Long-Term Plan

— Hydrocortisone 15–25 mg/day divided, with emergency IM injection kit and written sick-day rules.

— Levothyroxine dosed to free T4 mid-upper normal.

— Estrogen/progestin (premenopausal) — oral or transdermal.

— Calcium 1000–1200 mg + vitamin D 800–1000 IU daily for bone health.

— Bisphosphonate if osteoporosis confirmed on DEXA.

— GH replacement if deficiency confirmed and clinically indicated.

— Statin if dyslipidemia meets ASCVD guidelines.

— Stress-dose steroid rules (2× for fever, 3× for vomiting, IM for inability to keep down PO).

— MedicAlert bracelet/necklace indicating adrenal insufficiency.

— Emergency injection kit training — teach patient AND a family member.

— Avoid abrupt discontinuation of any replacement hormone.

— Inform every new provider (dental, surgical, ED) of steroid dependence.

— Annual influenza, COVID-19, pneumococcal (PCV20 or PCV15+PPSV23), shingles (≥50), Tdap. Chronic steroids do not contraindicate inactivated vaccines.

— Avoid live vaccines if on supraphysiologic steroid doses (>20 mg/day prednisone-equivalent for >2 weeks).

— Adequate salt intake (especially in hot weather, illness).

— Weight-bearing exercise for bone health.

— Smoking cessation, alcohol moderation.

— Mediterranean-style diet for cardiovascular risk reduction.

Core discharge medication list:

Patient education essentials (deliver and document):

Vaccinations:

Lifestyle:

Long-term cancer screening: Standard age-appropriate; estrogen use does not contraindicate but warrants breast cancer surveillance.

Key distinction: Sheehan is not a hypercoagulable state per se, but estrogen replacement raises VTE risk — use transdermal if any baseline risk (smoking, obesity, prior VTE).

Board pearl: The single most life-saving intervention at discharge is the stress-dose steroid education + emergency injection kit + MedicAlert ID triad. Skipping any one is a sentinel safety lapse.

Step 3 management: Build a templated Sheehan discharge bundle into the EHR — it ensures every patient leaves with the safety triad and reduces readmission risk for crisis.

Follow-Up, Monitoring Parameters, Rehab/Counseling

— Initial titration phase: every 4–8 weeks until stable on hydrocortisone, levothyroxine, and HRT.

— Maintenance: every 6 months with endocrinology; annual primary care visit reinforcing safety counseling.

— Post-illness/surgery: within 1–2 weeks to assess stress-dose response and resume baseline.

— Adrenal: Clinical (weight, BP, energy, Cushingoid features). Routine ACTH/cortisol unhelpful on replacement; monitor for over- or under-replacement symptomatically.

— Thyroid: Free T4 every 6 months once stable (TSH NOT useful in central disease).

— Gonadal: Symptom-based; estradiol levels optional; annual breast exam, biennial mammography per guidelines.

— GH: IGF-1 every 6 months on replacement, target mid-normal.

— Bone: DEXA every 2 years.

— Metabolic: Annual fasting lipids, A1c, electrolytes, CBC.

— Pituitary imaging: Repeat MRI only if new symptoms (mass effect, headache, visual change) or atypical course.

— Mental health: screen for depression (PHQ-9), anxiety; refer for CBT or pharmacotherapy as needed.

— Sexual health: address dyspareunia, libido, intimacy concerns; vaginal estrogen if systemic insufficient.

— Fertility: refer to reproductive endocrinology when family planning desired.

— Lactation grief: explicitly address when caring for women postpartum.

— Support groups (Pituitary Network Association, AdrenalCrisis.com) for peer support.

— Carry double the daily steroid dose plus emergency kit.

— Document a stress-dose plan in patient's chart and on a pocket card.

— International travel: carry physician letter and medications in original containers.

Follow-up cadence:

Monitoring parameters by axis:

Counseling and rehab:

Sick-day and travel counseling annually:

Key distinction: Following TSH in central hypothyroidism is a guaranteed wrong answer on Step 3. Always follow free T4.

Board pearl: Annual reinforcement of the stress-dose plan is the most evidence-aligned intervention to prevent crisis-related death.

Step 3 management: Build a yearly "Sheehan safety check" template: dose review, injection kit refill, MedicAlert verification, DEXA scheduling, vaccine update.

Ethical, Legal, and Patient Safety Considerations

— Missed stress dosing during intercurrent illness or surgery is the leading preventable cause of adrenal-crisis mortality. Mandatory pre-op communication between surgeon, anesthesia, and primary care.

— Medication reconciliation errors at hospital admission/discharge — hydrocortisone is often inadvertently omitted or under-dosed. Use forced-function order sets.

— Transitions of care — handoffs to new PCPs, OB providers, or specialists must include explicit Sheehan diagnosis, replacement regimen, and stress-dose plan. Provide patients with a written care summary they can carry.

— Look-alike/sound-alike risk: hydrocortisone vs hydrochlorothiazide — verify spelling on every script.

— Subsequent pregnancy: discuss maternal mortality risk (peripartum adrenal crisis), miscarriage, IUGR, and the need for intensive antenatal management. Document shared decision-making.

— GH replacement: discuss cost, daily injections, potential malignancy concerns; require informed consent.

— Estrogen therapy: review VTE, stroke, and breast cancer risk; document discussion.

— Disability accommodation: Sheehan patients may qualify for workplace accommodations (rest breaks, flexible scheduling during illness). Provide documentation when requested.

— Pre-operative documentation: Failure to document and communicate stress-dose requirements is a known malpractice exposure — anesthesia teams expect this in the H&P.

— Driving safety: Counsel that hypoglycemia and untreated hypothyroidism impair driving; advise against driving when symptomatic.

— Resource-limited settings: Sheehan remains a marker of inadequate obstetric care; advocate for universal skilled birth attendance and active management of the third stage of labor.

— Reproductive autonomy: Respect patient choice regarding subsequent pregnancy after thorough risk discussion; do not impose contraception.

Patient safety — high-yield issues:

Informed consent edge cases:

Legal and regulatory considerations:

Ethics:

Mandatory reporting: Not typically applicable; but consider reporting if the index obstetric event raises concerns of substandard care (institutional review, not law enforcement).

Board pearl: A surgeon who operates on a Sheehan patient without stress-dose coverage that results in crisis death is a classic medical malpractice vignette — the failure point is communication, not knowledge.

Step 3 management: Make every visit a safety reinforcement visit — it is both clinically appropriate and medicolegally protective.

High-Yield Associations and Rapid-Fire Clinical Facts

— Low cortisol + low/normal ACTH = secondary AI.

— Low free T4 + low/normal TSH = central hypothyroidism.

— Low estradiol + low LH/FSH = secondary hypogonadism.

— Low prolactin (distinguishes from stalk-effect lesions).

— Hyponatremia, normokalemia, hypoglycemia.

— Sheehan: low prolactin, empty sella, PPH history.

— Hypophysitis: high/normal prolactin, enlarged enhancing gland, headache.

— Apoplexy: acute headache + visual loss + adenoma hemorrhage.

— Addison: hyperpigmented + hyperkalemic.

Pathognomonic triad: Postpartum hemorrhage → failure to lactate → failure to resume menses.

Hormone loss sequence (memorize): GH → PRL → LH/FSH → TSH → ACTH (most to least vulnerable, generally). ACTH loss is the most dangerous.

Lab signature:

Imaging: Empty sella on MRI = classic chronic finding.

Treatment order: Hydrocortisone first, then levothyroxine. Reversing precipitates crisis.

Monitoring: Free T4 (not TSH) in central hypothyroidism. IGF-1 for GH. Clinical for cortisol.

No mineralocorticoid needed (aldosterone preserved via RAS).

No hyperpigmentation (low ACTH, no MSH).

Posterior pituitary spared — DI uncommon (separate blood supply).

Stress-dose rule: Double for fever/minor stress, triple/parenteral for surgery/severe illness, 100 mg IV q8h for major stress.

MedicAlert ID + emergency injection kit = standard of care.

Subsequent pregnancy: Possible with gonadotropin/GnRH induction; manage with MFM + endocrine.

Differentials cheat sheet:

Most lethal complication: Adrenal crisis during intercurrent illness.

Most modifiable risk factor: Quality of obstetric hemorrhage management — active management of the third stage of labor, uterotonics, blood product access.

Board pearl: Three Step 3 buzzwords — "failure to lactate," "amenorrhea after hemorrhagic delivery," and "empty sella" — converge on a single diagnosis.

Key distinction: Central vs primary is the conceptual axis tested most often — paired hormone interpretation answers nearly every Sheehan stem.

Step 3 management: When in doubt, give steroids first, ask questions second.

Board Question Stem Patterns

— A 35-year-old woman presents with fatigue, cold intolerance, and amenorrhea for several years. She delivered her only child 8 years ago, complicated by severe postpartum hemorrhage requiring transfusion. She never resumed menses or breastfed. Exam: pale, dry skin, sparse axillary hair, BP 95/60. Labs: Na 130, normal K, low free T4 with low-normal TSH, low cortisol with low ACTH, low LH/FSH/estradiol, low prolactin.

— Answer: Sheehan syndrome. Next step: start hydrocortisone before levothyroxine; obtain pituitary MRI showing empty sella.

— Day 3 postpartum after a delivery with 2-L blood loss, a patient has persistent hypotension despite fluids, glucose 50, Na 128, K 4.0. Failure to lactate noted.

— Answer: Acute Sheehan / adrenal crisis. Next step: IV hydrocortisone 100 mg, D5NS, ICU admission; draw cortisol/ACTH if not delaying treatment.

— A patient with hypothyroid features and amenorrhea. Stem includes prolactin level.

— Low prolactin → Sheehan. High prolactin → prolactinoma or stalk effect.

— Patient started on levothyroxine alone for "hypothyroidism" weeks ago, now hypotensive and obtunded.

— Answer: Precipitated adrenal crisis. Next step: IV hydrocortisone. Lesson: always check ACTH axis before thyroid replacement when central disease suspected.

— Known Sheehan patient scheduled for elective cholecystectomy. Surgeon does not coordinate steroid coverage.

— Answer: Stress-dose hydrocortisone 100 mg IV at induction, then q8h; safety/communication failure if omitted.

— Sheehan patient pregnant again at 12 weeks.

— Answer: Increase levothyroxine by 30%, continue hydrocortisone with stress-dose plan for labor, MFM + endocrine co-management.

— Stem describes empty sella on MRI + PPH history.

— Answer: Sheehan; obtain pituitary hormone panel.

Pattern 1 — Classic chronic vignette:

Pattern 2 — Acute postpartum collapse:

Pattern 3 — Differential trap:

Pattern 4 — Wrong-order treatment:

Pattern 5 — Perioperative pitfall:

Pattern 6 — Subsequent pregnancy:

Pattern 7 — Imaging:

Board pearl: Read the prolactin level and the ACTH/TSH pattern first — they collapse the differential in seconds.

Step 3 management: "Next best step" in any unstable adrenal-axis stem is IV hydrocortisone — bias your answer toward treating before testing.

One-Line Recap

Sheehan syndrome is postpartum ischemic anterior-pituitary necrosis from peripartum hemorrhage that produces a sequential loss of pituitary hormones (classically prolactin and gonadotropins first, ACTH last and most dangerously), diagnosed by paired low-trophic/low-peripheral hormone patterns plus an empty sella on MRI, and managed with lifelong hydrocortisone started before levothyroxine, sex-steroid and GH replacement as indicated, and obsessive stress-dose education to prevent adrenal crisis.

— Trigger: Severe postpartum hemorrhage with hypotension → infarction of physiologically enlarged pituitary.

— Hallmark history: Failure to lactate + failure to resume menses after a hemorrhagic delivery — pathognomonic when combined.

— Lab signature: Low cortisol with low/normal ACTH, low free T4 with low/normal TSH, low estradiol with low LH/FSH, low prolactin, hyponatremia with normal potassium, occasional hypoglycemia.

— Imaging: Empty sella on pituitary MRI in chronic disease; consider hypophysitis (enhancing enlarged gland) and apoplexy (hemorrhagic mass) as differentials.

— Treatment order: Hydrocortisone FIRST, then levothyroxine, then sex steroids, then GH — never reverse the first two.

— Monitoring: Free T4 (not TSH) in central hypothyroidism; clinical assessment for cortisol replacement; IGF-1 for GH; DEXA q2y.

— Safety triad: Stress-dose steroid education + emergency IM hydrocortisone kit + MedicAlert ID — required at every visit.

— Crisis management: Adrenal crisis = IV hydrocortisone 100 mg + fluids + glucose + ICU + search for precipitant; treat before confirmatory testing.

— Pregnancy: Possible with gonadotropin induction; increase levothyroxine 30%, intensify steroid coverage peripartum, MFM co-management.

— Key distinction: Sheehan (secondary AI) has no hyperpigmentation and no hyperkalemia — separates cleanly from Addison disease on every board stem.

High-yield recap bullets:

Step 3 management: Diagnose with paired hormones, treat in the correct order, and prevent the next crisis with relentless safety counseling — these three actions answer nearly every Sheehan question on the exam and protect every Sheehan patient in practice.