SUPERStudy: Sheehan Syndrome

By usmlevideoss

Introduction

  • Definition: Postpartum hypopituitarism caused by ischemic necrosis of the anterior pituitary gland following severe postpartum hemorrhage or hypovolemic shock.
  • Result: Varying degrees of pituitary hormone deficiencies.

Pathophysiology

  • Pregnancy Adaptations:
    • During pregnancy, the anterior pituitary undergoes hypertrophy and hyperplasia to meet increased hormone demands, making it highly vascular and susceptible to ischemia.
  • Trigger: Severe postpartum blood loss or hypovolemia leads to reduced blood flow, infarction, and necrosis of the anterior pituitary.
  • Hormonal Effects:
    • Deficiencies in prolactin, growth hormone (GH), gonadotropins (LH, FSH), thyroid-stimulating hormone (TSH), and adrenocorticotropic hormone (ACTH).
    • The posterior pituitary is usually spared due to a separate blood supply.
  • Delayed Diagnosis: In some women, diagnosis may occur years later (average 13 years).

Clinical Features

  1. Postpartum Symptoms (Acute Phase):
    • Failure to lactate (prolactin deficiency).
    • Severe fatigue.
    • Hypotension or shock (if cortisol production is significantly affected).
  2. Chronic Symptoms (Delayed Presentation):
    • Amenorrhea or Oligomenorrhea: From gonadotropin (LH/FSH) deficiency.
    • Hypothyroidism: Fatigue, cold intolerance, constipation, and weight gain (TSH deficiency).
    • Adrenal Insufficiency: Hypotension, fatigue, hypoglycemia, poor stress tolerance (ACTH deficiency).
    • Loss of Secondary Sexual Characteristics: Decreased libido, breast atrophy, loss of pubic/axillary hair.
    • Growth Hormone Deficiency: Generalized weakness, decreased muscle mass, low energy.
  3. Physical Exam Findings:
    • Pale skin (reduced melanocyte-stimulating hormone).
    • Hypotension or signs of adrenal insufficiency.

Diagnosis

  1. History:
    • Key clues include severe postpartum hemorrhage and inability to lactate.
  2. Laboratory Tests:
    • Low levels of pituitary hormones: TSH, ACTH, LH, FSH, prolactin, GH.
    • Low levels of downstream hormones: Free T4, cortisol, estradiol.
    • Normal or low serum sodium (due to adrenal insufficiency).
  3. Imaging:
    • MRI of the Pituitary: May show an atrophic or empty sella (chronic cases) or signs of infarction (acute phase).

Management

  • Hypothyroidism: Levothyroxine.
  • Gonadotropin Deficiency: Estrogen and progesterone (premenopausal women).
  • Growth Hormone Deficiency: Recombinant GH in symptomatic cases.
  1. Supportive Care:
    • Treat underlying anemia or hypovolemia if present.
    • Provide psychological support for chronic hormone deficiencies.
    • Ensure the patient has a steroid emergency card for adrenal crises.

Prognosis

  • With proper hormone replacement, most patients can lead normal lives.
  • Untreated cases may result in life-threatening complications, particularly adrenal insufficiency.

Key Points

  1. Etiology: Severe postpartum hemorrhage is the primary cause.
  2. Early Signs: Failure to lactate and fatigue are hallmark early symptoms.
  3. Delayed Presentation: Non-specific symptoms like amenorrhea and fatigue may appear years later.
  4. Lifelong Management: Hormone replacement therapy tailored to individual deficiencies.
  5. Prevention: Early recognition and treatment of postpartum hemorrhage.

SUPERPoint

Sheehan syndrome is postpartum hypopituitarism caused by severe postpartum hemorrhage, leading to hormone deficiencies, with hallmark early signs like failure to lactate and fatigue, requiring lifelong hormone replacement therapy for effective management.

SUPERFormula

Patient presents with failure to lactate and fatigue, amenorrhea, hypothyroidism, adrenal insufficiency, or loss of libido + history of severe postpartum hemorrhage or hypovolemic shock + Postpartum hypopituitarism due to ischemic necrosis of the anterior pituitary + Results in deficiencies of prolactin, TSH, ACTH, LH/FSH, and GH + MRI of the Pituitary show an atrophic or empty sella+ Treated with lifelong hormone replacement therapy (corticosteroids, levothyroxine, sex hormones, and GH if needed) = Sheehan syndrome 

References: 

Williams Obstetrics, 26e

Gary Cunningham, Kenneth J. Leveno, Jodi S. Dashe, Barbara L. Hoffman, Catherine Y. Spong, Brian M. Casey

CURRENT Diagnosis & Treatment: Obstetrics & Gynecology, 12e

Alan H. DeCherney, Lauren Nathan, Neri Laufer, Ashley S. Roman