Amenorrhea Flashcards
What is the definition of primary amenorrhea?
No menses without secondary sex characteristics by age 14 OR No menses with secondary sex characteristics by age 16 (ASRM says 13 and 15)
What is the differential for primary amenorrhea?
1) hypergonadotropic hypogonadism: 45XO, 46XX, 46XY
2) eugonadism: AIS, Cushing’s, CAH, PCOS, thyroid disease, mullerian agenesis, vaginal septum, imperforate hymen
3) hypogonadotropic hypogonadism (low FSH): constitutional delay, eating disorder, stress, exercise, pituitary disease, GnRH deficiency,
What are the most common causes of primary amenorrhea?
1) primary dysgenesis (Turner’s) 45%
2) Mullerian Agenesis 15%
3) Physiologic delay (constitutional, chronic disease, acute illness) 15%
4) PCOS 5%
What is the definition of secondary amenorrhea?
No menses for 3 months or oligomenorrhea (<9 periods in a year)
What is the ddx for secondary amenorrhea?
1) Low/N FSH: stress, eating disorder, exercise, hypothalamic, PCOS, hypothyroid, Sheehan syndrome, pituitary tumour/empty sella, Cushing
2) High FSH (gonadal failure): POI, 46XX, abnormal karyotype
3) High prolactin: prolactinoma, anti-psychotics
4) Anatomic: Asherman’s
5) Hyperandrogenic: non-classic CAH, ovarian tumour
What is Mayer-Rokitansky-Kuster-Hauser syndrome?
Complete agenesis of mullerian tract from upper vagina
How is Premature Ovarian Insufficiency diagnosed?
hypergonadotropic (2 FSH levels > 30 at least a month apart)
loss of oocytes before age 40
What is the ddx for causes of Premature Ovarian Insufficiency?
1) Genetic: chromosomal, normal chromosome, galactosemia,
2) Iatrogenic: ovarian surgery, rads, chemo
3) Autoimmune disease: SLE
4) Toxins: smoking, solvents
5) Viruses: mumps
What is the pathophysiology of primary gonadal dysgenesis?
Normal number of germ cells to begin with –> accelerated atresia –> fibrous streak gonads
What is the pathophysiology in Swyer syndrome?
What tx is necessary?
46XY phenotypic females due to absent testosterone and AMH
Streak gonads must be removed (25% risk of malignancy)
How does fragile X work cause premature ovarian failure?
single gene mutation (fMR1 = most common cause of mental retardation and autism)
>200 CGG repeats = full mutation -silences gene expression after hypermethylation
50-200 CGG repeats = males have tremor/ataxia, females have 15-25% risk of POF
List 5 acquired causes of premature ovarian failure:
1) mumps oophoritis
2) cigarette smoke
3) heavy metals/solvents
4) auto-immune (40% of cases): SLE, thyroid, pituitary polyglandular failure, myasthenia gravis, RA, ITP
5) radiation/chemo exposure
6) surgical: removal of ovaries, endometriosis, PID
What is the pathophysiology of hypogonatropic hypogonadism?
Problem in HPO axis, usually low FSH/LH –> poor stimulation of ovaries
What is the most common genetic cause of idiopathic hypogonadotropic hypogonadism?
What are the associated genetic abnormalities?
Kallman’s syndrome - anosmin-1 adhesion protein mutation (associated anosmia), protein needed for GNRH neuron migration
Associated abnormalities: anosmia, midline facial anomalies, cleft palate, unilateral renal agenesis, cerebral ataxia, epilepsy
Select all correct statements:
a) acquired hypogonadotropic hypogonadism is more common than inherited causes
b) stress causes amenorrhea through increased CRH and cortisol which both inhibit GnRH pulsatility
c) exercises can cause amenorrhea through endorphin which act as endogenous opioids inhibiting GnRH pulsatility
d) eating disorders can cause amenorrhea through a multifactorial process including insulin, IGF, grehlin, leptin interrupting ovulation
a) true
b) true
c) true
d) true
