GYN- Amenorrhea

Question 1

how to define 1/1 and 2/2 amenorrhea

Answer 1

1/1: absence of menarche by age 16 or 4 yrs after thelarche

2/2: absence of menses for 6 mos, had periods at one time

Question 2

what are the 3 types of etiologies of 1/1 amenorrhea?

Answer 2

outflow tract obstruction
end organ disorder
central regulatory disorder

Question 3

what are the outflow tract obstructions that can cause 1/1 amenorrhea?

Answer 3

• imperforate hymen
• transverse vaginal septum
• MRKH syndrome (mullerian agenesis or dysgenesis= lack of uterus and upper vagina)
• vaginal atreasia
• androgen insesitivity syndrome (mut T receptor –> 46, XY female with blind pouch vagina)

Question 4

what are central regulatory disorders that can cause 1/1 amenorrhea?

Answer 4

something wrong with GnRH or FSH/LH release

• kallmann syndrome: lack arcuate + olfactory nuclei (no GnRH release + anosmia), Dx olfactory challenge, Tx exogenous GnRH (pulsatile)
• Craniopharyngioma: rathke’s puch tumor –> pituitary compression, Dx supracellar calcified cysts

Question 5

What are end organ disorders that can cause 1/1 amenorrhea?

Answer 5

ovaries will not respond to FSH/LH

• Savage syndrome: mut FSH/LH receptor
• Turner’s syndrome: rapid ovarian atresia –> streak ovaries w/o oocytes left
• 17a hydroxylase def: cannot produce T but still have MID –>< 46, XY female with blind pouch vagina
• Swyer syndrome: male w/o testes –> 46, XY female w/ both internal and external female genitalia

Question 6

FSH, LH, E2 levels assc with 1/1 amenorrhea due to

central d/o
ovarian d/o
outflow tract obstruction

Answer 6

central d/o: low FSH/LH, low E2

ovarian d/o: high FSH/LH, low E2

outflow tract obstruction: normal FSH/LH, normal E2

Question 7

1/1 amenorrhea management

Answer 7

1st: det if there is a uterus
- no uterus = MIF present = get karyotype to show 46, XY female

2nd: if there is a uterus, is there a vagina too?
- no vagina = outflow tract obst

3rd: are there breasts?
- breasts = E present = Progesterone challenge + (gets withdrawal bleeding)
- no breasts = E absent = Progesterone challenege negative (no withdrawal bleeding, bc the endometrium is not estrogenized)

Question 8

what are the 4 types of etiologies for 2/2 amenorrhea?

Answer 8

pregnancy (MC)
acquired abnormalities
hyperPRL
HPO axis disorder

Question 9

What are aquired causes of 2/2 amenorrhea?

Answer 9

anatomic or ovarian abnormalities

• Asherman syndrome syndrome (intrauterine adhesions 2/2 to D&C, surgery, or endometritis)
• Cervical stenosis: surgical or obstetric trauma leading to scarring of cervical os
• PCOS: elevated LH, dec FSH, elevated E/T

Question 10

why does hyperPRL lead to amenorrhea?

Answer 10

PRL inhibits GnRH (elevated TSH, dec DA, tumors)

Question 11

decision tree for 2/2 amenorrhea?

Answer 11

1st: check b-hCG to r/o pregnancy

2nd check PRL

• elevated, get TSH
• normal give P challenge

3rd:
elevated PRL and TSH = hyperthyroid causing amenorrhea

elevated PRL, nml TSH, abnormal cone view –> get CT/MRI head to determine if micro or macroadenoma (micro tx is bromocriptine; macro tx is surgery)

normal PRL with positive P challengre (gets withdrawal bleeding) –> hirsute = PCOS and non-hirsute = milkd hypothalamic dysfunction

normal PRL with negative P challenge test, 1st r/o asherman syndrome/cervical stenosis (= aquired obstructions) then get FSH.

• FSH > 40 = ovarian failure
• FSH < 40 = severe hypothalamic dysfucntion