Gynecology - Secondary Amenorrhea

Gynecology

[SECONDARY AMENORRHEA]

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

↑  ↑

4.

Medications

Prolactin

↑

Treatment Prenatal Care Levothyroxine Surgery or Bromocriptine Switch or D/C

 Emotional Stress

Hypothalamus  Anorexia

5. Diagnosis of Exclusion

Weight Loss / Exercise

Ant Pit

 Adenoma Sheehan’s  Apoplexy

Ovary

 Menopause  Resistant Ovary

Endometrium

4. MRI

 Asherman’s  Ablation

3. FSH/LH and U/S

2. Estrogen and Progesterone 1. Progestin Challenge

See the correlation to the algorithm on the n ext page

TRH

Hypothalamus

Ant Pituitary TSH

GnRH

Prolactin

Dopamine

Dopa Antag

FSH LH

Ovary

T4 Endometrium

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!

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Gynecology

[SECONDARY AMENORRHEA]

Menopause If menopause occurs in a woman