LECTURE 29 - endocrine disorders affecting reproduction Flashcards
What are the 3 main ways in which endocrine disorders affecting reproduction can be acquired?
- congenital
- failure of full maturation at puberty
- acquired
May only be detected when there are problems conceiving
What is androgen insensitivity syndrome (XY)
- due to mutations in the androgen receptor (AR)
- occurs on a spectrum from partial –> complete
- affects 46 XY
- testis develop normally and secretes androgens
- insensitivity of fetus to androgens => Wolffian duct degenerates + female external genitalia formed - assigned female gender at birth
Presentation - inguinal hernia
- primary amenorrhoea (absence of periods)
What is 5α-reductase deficiency?
- affects 46XY
- unable to convert testosterone to DHT - required for male external genitalia
- appear female or have ambiguous genitalia
- primary amenorrhoea
- virilisation at puberty - male secondary sexual characteristics
- gender change
What is Kallmann syndrome?
- affects 1/10,000
- failure of migration of GnRH neurons, therefore cannot produce GnRH
- normally these neurones start off as precursors in olfactory placode, migrate to hypothalamus in development
- anosmia in 75% (no sense of smell)
What is precocious puberty?
- onset of secondary sexual characteristics before 8yrs (girls) or 9yrs (boys)
- F= 1/10,000
- M=1/50,000
- linked to short stature - premature fusion of epiphyses
Central causes
- sex hormones produced too early by HPG axis
- idiopathic - constitutional (no known cause)
- environmental endocrine disruptors
- obesity
Peripheral causes
- sex hormones produced by atypical means
- adrenal hyperplasia or tumour
What is delayed puberty?
- absence of SCC by 14yrs (girls) or 16yrs (boys)
- 95% constitutional - familial
- chemo/radiotherapy
- pituitary tumours
- Turner syndrome
- Kallmann syndrome
- AIS, 5α-reductase deficiency
How long is a normal menstrual cycle?
- 28 days is normal
- can be 26-32
- day 1 = first day of menses
What is amenorrhea?
- absence of menstrual cycle for more than 6 months
- primary amenorrhea - no menarche after 16yrs
- secondary amenorrhea = cased
Oligomenhorrhea = irregular cycles (less than 9 per year)
What are the presenting symptoms of endocrine disorders?
- oligomenhorrhea or amenorrhea
- infertility ~60% endocrine
- oestrogen deficiency
- hot flushes, poor libido, dyspareunia (painful intercourse)
- hyperandrogenism
- hirsutism, acne, androgenic alopecia
- galactorrhoea (breast milk without having baby)
What are the 3 main things that can go wrong with the HPG axis?
- Hypothalamic/pituitary disease - secondary/central causes
- Gonadal damage/failure - peripheral/primary causes
- Polycystic ovary syndrome
How are these endocrine disorders diagnosed?
- amenorrhea = pregnancy test (most likely issue)
- FSH/LH: test on day 2/3 - ovarian reserve, HPG disorders
- progesterone - day 21, test for ovulation
What is the progesterone withdrawal bleed test?
- aka progesterone challenge test
- used on amenorrheic women
- medroxyprogesterone acetate - 5 days
- bleed 2-7 days after completion of course
What are the primary causes of issues with the HPG axis?
- ovarian insensitivity/damage
- gonadotrophin secretion is normal
- high FSH/LH due to absence of feedback from oestrogen
What is premature ovarian failure?
- amenorrhea, low oestrogen, high FSH/LH - prior to age of 40 years
- affects 1% of women
Causes - often unknown
- congenital = Turner syndrome
- autoimmune
- latrogenic - chemotherapy and radiotherapy, surgery
What is Turner syndrome?
- XO - complete of mosaic
- affects ~1/2000
- normal oocyte growth requires both X chromosomes –> oocyte death
- normal ovary development requires normal germ cells –> ovarian dysgenesis
- can alleviate condition by giving growth hormone and oestrogen support
