Question:hard
A 32-year-old woman complains of amenorrhea since the delivery of a baby 15 months earlier, despite the fact that she did not breastfeed. The delivery was complicated by excessive haemorrhage requiring transfusion of 2.5 litres of blood. She has also been fatigued and has gained 4.5 kg since the baby was born. Laboratory data: serum LH < 1 IU/L (normal 4-24), serum estradiol 5 pg/mL (normal 20-100), serum TSH 0.1 mU/L (normal 0.5-5), serum GH 3 ng/mL (normal < 5), serum ACTH 28 pg/mL (normal 10-50), serum prolactin 2 ng/mL (low). Injection of 500 microgram of TRH failed to produce the expected rise in both serum TSH and prolactin. Which diagnosis most likely explains these findings?
A 32-year-old woman complains of amenorrhea since the delivery of a baby 15 months earlier, despite the fact that she did not breastfeed. The delivery was complicated by excessive haemorrhage requiring transfusion of 2.5 litres of blood. She has also been fatigued and has gained 4.5 kg since the baby was born. Laboratory data: serum LH < 1 IU/L (normal 4-24), serum estradiol 5 pg/mL (normal 20-100), serum TSH 0.1 mU/L (normal 0.5-5), serum GH 3 ng/mL (normal < 5), serum ACTH 28 pg/mL (normal 10-50), serum prolactin 2 ng/mL (low). Injection of 500 microgram of TRH failed to produce the expected rise in both serum TSH and prolactin. Which diagnosis most likely explains these findings?
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Heavy postpartum bleeding plus failure to lactate plus several low pituitary hormones points one way.
Updated On: Jun 23, 2026
- Hashimoto's thyroiditis
- Isolated gonadotropin deficiency
- Primary amenorrhea
- Sheehan's syndrome
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The Correct Option is D
Solution and Explanation
Pattern recognition: a young mother with a history of massive postpartum haemorrhage who then cannot lactate, stops menstruating, gains weight, and feels tired is the textbook picture of Sheehan syndrome, that is, ischaemic necrosis of the anterior pituitary.
Reading the labs as a panel: LH is low and estradiol is low, so the gonadal axis is down (amenorrhea). TSH is low yet there is hypothyroidism, and TRH fails to push TSH up, so the thyroid axis fails at the pituitary level, that is secondary hypothyroidism. Prolactin is low and does not rise to TRH, matching the failure to breastfeed. ACTH is normal, telling you the corticotrophs were partly spared, a common feature.
Eliminating distractors: Hashimoto thyroiditis (option 1) raises TSH, the opposite of this case. Isolated gonadotropin deficiency (option 2) would touch only LH and FSH and cannot account for the low TSH, low prolactin, and flat TRH test. Primary amenorrhea (option 3) is impossible in a woman who has already given birth.
Several pituitary axes are knocked out together after a haemorrhagic delivery, so the answer is Sheehan syndrome. Ref: Williams Obstetrics.
Reading the labs as a panel: LH is low and estradiol is low, so the gonadal axis is down (amenorrhea). TSH is low yet there is hypothyroidism, and TRH fails to push TSH up, so the thyroid axis fails at the pituitary level, that is secondary hypothyroidism. Prolactin is low and does not rise to TRH, matching the failure to breastfeed. ACTH is normal, telling you the corticotrophs were partly spared, a common feature.
Eliminating distractors: Hashimoto thyroiditis (option 1) raises TSH, the opposite of this case. Isolated gonadotropin deficiency (option 2) would touch only LH and FSH and cannot account for the low TSH, low prolactin, and flat TRH test. Primary amenorrhea (option 3) is impossible in a woman who has already given birth.
Several pituitary axes are knocked out together after a haemorrhagic delivery, so the answer is Sheehan syndrome. Ref: Williams Obstetrics.
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