Question

A 32-year-old woman complains of amenorrhea since the delivery of a baby 15 months previously, despite the fact that she did not breastfeed her baby. The delivery was complicated by excessive hemorrhage that required a transfusion of 2.5 liters of blood. She has also been fatigued and has gained an additional 4.5Kg since the baby was born.
Laboratory data show the following: Serum LH < 1 IU/L (normal, 4-24 IU/L)
Serum estradiol 5 pg/mL (normal, 20 - 100 pg/mL) Serum TSH 0.1 mU/L (normal, 0.5 - 5 mU/L)
Serum GH 3 ng/mL (normal, < 5 ng/mL) Serum ACTH 28 pg/mL (normal, 10 - 50 pg/mL)
Serum prolactin 2 ng/mL (normal, Injection of 500 μg of TRH failed to produce the expected rise in both serum TSH and prolactin.
Which of the following diagnoses most likely explains the findings in this patient ?

• A. Hashimoto's thyroiditis
• B. Isolated gonadotropin deficiency
• C. Primary amenorrhea
• D. Sheehan's syndrome

Answer 1

The Correct Option is D

To determine the correct diagnosis for this patient, we need to analyze the provided symptoms and lab results in the context of possible conditions. The patient is a 32-year-old woman experiencing amenorrhea 15 months post-delivery, with significant fatigue and weight gain. Her delivery involved severe hemorrhage requiring a blood transfusion. The key laboratory findings are:

• Serum LH < 1 IU/L (normal: 4-24 IU/L)
• Serum estradiol 5 pg/mL (normal: 20-100 pg/mL)
• Serum TSH 0.1 mU/L (normal: 0.5-5 mU/L)
• Serum GH 3 ng/mL (normal: < 5 ng/mL)
• Serum ACTH 28 pg/mL (normal: 10-50 pg/mL)
• Serum prolactin 2 ng/mL (normal: Injection of 500 μg of TRH failed to produce expected rise in TSH and prolactin

The most pertinent symptoms are amenorrhea, fatigue, and the laboratory results indicating low LH, estradiol, TSH, and prolactin. The history of postpartum hemorrhage is crucial, suggesting possible pituitary damage. Considering the options:

• Hashimoto's thyroiditis: This usually results in hypothyroidism with elevated TSH, not suppressed TSH as seen here.
• Isolated gonadotropin deficiency: Would not explain the low TSH and prolactin without other pituitary hormone deficiencies.
• Primary amenorrhea: Refers to the absence of menstruation by age 15-16; irrelevant post-delivery.
• Sheehan's syndrome: Classic case of postpartum pituitary gland necrosis due to hemorrhage. Explains low levels of multiple pituitary hormones (LH, TSH, prolactin) and corresponding symptoms (amenorrhea, fatigue, weight gain).

Conclusion: The findings and clinical history are most consistent with Sheehan's syndrome, where the pituitary gland fails to produce essential hormones due to postpartum necrosis following significant blood loss.