amenorrhoea Flashcards
what are the different types of amenorrhoea?
hypothalamic/pituitary amenorrhoea
gonadal amenorrhoea
outflow tract amenorrhoea
what are the primary causes of hypothalamic amenorrhoea?
inability to produce GnRH, therefore FSH
what are the secondary causes of hypothalamic amenorrhoea?
exercise
stress
eating disorders
what are the secondary pituitary causes of amenorrhoea?
Sheehan syndrome (hypopituitarism - under developed pituitary gland) hyperprolactinaemia (e.g. from prolactinoma - high circulating prolaction = no ovulation)
what is another cause of amenorrhoea which has no direct link to the HPG axis?
hypo/hyperthyroidism
what are the 2 causes of gonadal amenorrhoea?
primary and secondary
what are primary causes of gonadal amenorrhoea?
Turner’s syndrome (gonadal dysgenesis)
FSH/LH receptor abnormalities
congenital adrenal hyperplasia
what is CAH?
marked underproduction of glucocorticoids (loose Na+) and hyperandrogenism (adrenal androgens)
how do females with CAH appear at birth?
ambiguous genitalia with an enlarged clitoris (high circulating testosterone) and a common urogenital sinus in place of a separate urethra and vagina (normal internal genitalia)
normal internal genitalia (default gender, without MIH from testis)
how do males with CAH appear at birth?
no signs at birth, except subtle hyperpigmentation and possible penile enlargement. The age at diagnosis depends on the severity of aldosterone deficiency
what are symptoms of CAH?
Rapid growth in childhood and early teens but shorter height than both parents
Early signs of puberty
Acne
ogliomenorrhoea / amenorrhoea
infertility
hirsutism
Male-pattern baldness (hair loss near the temples)
what are secondary causes of gonadal amenorrhoea?
pregnancy menopause anovulation PCOS drug induced
what are symptoms of PCOS?
ogliomenorrhea / amenorrhoea (anovulation)
infertile (because of irregular ovulation or failure to ovulate)
excessive hair growth (hirsutism) – usually on the face, chest, back or buttocks
obesity
thinning hair and hair loss from the head
oily skin or acne
clinical presentation of PCOS?
Excess androgens produced by the theca cells of the ovaries (hyperinsulinaemia or increased LH levels)
Insulin resistance, ie loss of sensitivity to insulin, resulting in hyperinsulinaemia. Weight gain further increases insulin resistance
Raised LH: increased production from the anterior pituitary
Raised oestrogen, can lead to a hyperplastic endometrium
what are the effects of increased insulin resistance in PCOS?
Increased androgen production through more than one mechanism
Reduced production of sex hormone-binding globulin (SHBG) in the liver. Free testosterone may subsequently be raised as testosterone is bound to SHBG, even if total testosterone is normal
