••• Chapter 53^ Amenorrhea^535
❍ How does hyperthyroidism cause amenorrhea?
It inhibits gonadotropin release.
❍ How does hypothyroidism cause amenorrhea?
TrH stimulates prolactin secretion. It works by acting directly on prolactin secreting cells. In addition, the
deficiency of thyroid hormones (in hypothyroidism) affects dopamine’s inhibitory control of prolactin resulting in
hyperprolactinemia.
❍ If elevated TSH and prolactin levels are found in an amenorrhea workup, what do you treat?
only the hypothyroidism. The prolactin will normalize with the treatment of the hypothyroidism based on its
mechanism of causing amenorrhea.
❍ Hyperprolactinemia causes amenorrhea by what mechanisms?
Prolactin suppresses the GnrH pulsatile release necessary for ovulation and menstruation and increases opioid
activity. It may also act to reduce the granulosa cell number and FSH binding.
❍ What proportion of women with both galactorrhea and amenorrhea will have hyperprolactinemia?
Two-thirds.
❍ How is galactorrhea confirmed on examination of cloudy or white nipple secretions?
Microscopic examination of secretions demonstrates lipid droplets.
❍ What test is necessary in women with amenorrhea and hyperprolactinemia once drug induced and
physiologic causes of the elevated prolactin have been ruled out?
MrI of the sella turcica.
❍ In patients with galactorrhea and 2∞ amenorrhea, how many will have an abnormal sella turcica?
50%.
❍ What two diseases can cause endometritis and uterine scaring as a result?
Tuberculosis endometritis and schistosomiasis.
❍ A patient with amenorrhea due to absent FSH receptors or postreceptor defects has what syndrome?
The resistant ovary syndrome or Savage syndrome.
These patients have unstimulated ovarian follicles in their ovaries. In addition, there is no evidence of autoimmune
disease (ie, lymphocytic invasion), yet the ovaries are nonfunctional.
❍ Postpartum amenorrhea can be due to what?
Sheehan syndrome. It is postpartum necrosis of the pituitary from a hypotensive episode also causing failure to
lactate and loss of pubic and axillary hair.
❍ What is the classical presenting symptom of Sheehan syndrome?
Failed lactation.