Thanks to Patrick for presenting an interesting case of a 32F who presented with secondary amenorrhea.
1. Secondary amenorrhea is common and technically requires the absence of menses for 3 months in patients with previously regular periods, and 9 months in patients with oligomenorrhea.
2. Secondary amenorrhea develops due to pregnancy, progesterone deficiency, estrogenic deficiency or outflow tract obstruction. Pregnancy and progesterone deficiency are the most common causes. See below for an approach.
3. We do not directly measure progesterone and estrogen reveals in patients with amenorrhea. Instead we assess for a withdrawal bleed in response to these hormones. A withdrawal bleed after 5 days of oral progesterone is diagnostic of a progesterone deficiency.
Causes of secondary amenorrhea
Given the long list of possibilities, here is one way to approach patients.