536 obstetrics and Gynecology Board review •••
❍ Which hormone deficiencies are most common in Sheehan syndrome?
Growth hormone
Gonadotropins
Prolactin
❍ What percentage of body fat is necessary for the initiation of menses and then for the maintenance
of menses?
About 17% and 22%, respectively.
It is thought that decreasing weight can effect GnrH pulsatile secretion.
❍ What three items comprise the female athlete triad?
Amenorrhea.
Disordered eating.
osteoporosis/osteopenia.
❍ Name three causes of amenorrhea that are thought to be caused by abnormalities in neuromodulation in
hypothalamic GnRH secretion.
Anorexia, stress, and exercise.
❍ What is hypothalamic amenorrhea?
Defect in GnrH pulsatility frequently associated with stressful situations, probably secondary to elevated CrH/
cortisol which inhibits gonadal secretion.
❍ How does one diagnose hypothalamic amenorrhea?
All studies are normal—diagnosis of exclusion (note: gonadotropin may be low or normal) and failure to
demonstrate withdrawal bleeding.
❍ What is meant by the term post-pill amenorrhea?
This is the delay in return of menses after a woman stops taking oral contraceptives. Typically the hypothalamic-
pituitary suppression should not last >6 months after discontinuation of the pill. At that time the incidence of
amenorrhea is about the same as the incidence of secondary amenorrhea in the general population and therefore
thought to be unrelated to the use of oral contraceptives.
❍ What are three other causes of secondary amenorrhea due to affected pituitary function?
Lymphocytic hypophysitis—often occurring during pregnancy or 6 months postpartum.
Carotid artery aneurysm.
obstruction of aqueduct of Sylvius.
❍ Are leptin levels in anorectic and bulimic patients increased or decreased?
Decreased.