Introduction If a woman is within her reproductive age and was having periods that have since stopped for > 6 months she’s said to have secondary amenorrhea. Most OBs won’t wait 6 months to decide if she’s pregnant so diagnostic intervention can begin after just 2 cycles, even 1 for UPT. In general, the workup begins with the “three most common common causes” (pregnancy, (pregnancy, thyroid, and prolactin) then proceeds in reverse order of how the HP axis is set up; beginning with the endometrium, then the ovary, then the anterior pituitary with the hypothalamus as the diagnosis of exclusion. The chart and diagram to the right give an overview of the topics dis cussed and the order in which they should be investigated. The next page has an algorithm that can be used to work work up a patient with with secondary secondary amenorrhea. amenorrhea. Pregnancy The most common cause of 2o amenorrhea is pregnancy. Get a UPT to rule out pregnancy in every patient every time. There is a section called “OB” for this condition. Thyroid Disease While both hyper and hypo thyroidism can cause absence of bleeding or too much much bleeding, bleeding, it’s usually ↑TRH secondary to Hypothyroid that causes ↑ prolactin thereby inhibiting GnRH that leads to the amenorrhea. During the first visit we screen with a TSH alongside the UPT. If the TSH is elevated she needs synthroid (see medicine, endo). Pituitary Tumor (Prolactinoma) While a tumor of of the anterior pituitary can either cause crush syndrome (↓FSH and ↓LH), bleed (apoplexy), or die (Sheehan’s), it’s more likely that an otherwhise healthy woman would develop amenorrhea from a tumor that produces prolactin erroneously (the first free would make her much sicker than “just stopped bleeding”). Just as in thyroid disease, elevated prolactin will inhibit the axis and turn off her cycle. It doesn’t matter how you get prolactin; if you have there’s too much it messes with the axis. Sucpect prolactinoma if galactorrhea and amenorrhea. Screen her prolactin level and get an MRI if it’s elevated. The options are bromocriptine if small or surgery if large or desires pregnancy. See medicine, endo.
1. 2. 3.
Disease State State Pregnancy Thyroid Prolactin
Test UPT TSH Prolactin
Treatment Prenatal Care Levothyroxine Surgery or Bromocriptine Switch or D/C
5. Diagnosis of Exclusion
Weight Loss / Exercise
Adenoma Sheehan’s Apoplexy
Menopause Resistant Ovary
3. FSH/LH and U/S
2. Estrogen and Progesterone 1. Progestin Challenge
See the correlation to the algorithm on the n ext page
Ant Pituitary TSH
Means “inhibits” Means “stimulates Green = ↑FSH/LH = Normal Red = ↓ FSH/LH = Amenorrhea
Medications Anything that inhibits dopamine (aka Prolactin-Inhibiting Factor) will disinhibit prolactin . Unrestrained prolactin acts just like a prolactinoma prolactinoma (i.e. prolactinemia ), presenting with galactorrhea and amenorrhea. S witch medications (typically a typical for an atypical antipsychotic) or add bromocriptine. If it’s the medication that could be the culprit there’s no need for an MRI if you’ve found prolactinemia!