endocrine infertility

Question 1

what is the normal reproductive physiology in males?

Answer 1

• GnRH stimulates LH and FSH release

- these act on Sertoli and Leydig cells in testis to produce testosterone and inhibin

Question 2

what is the normal reproductive physiology in females?

Answer 2

• 28 day menstrual cycle
• follicular phase, ovulation and luteal phase
• high levels of oestradiol trigger switch to positive feedback on hypothalamus
• triggers large GnRH and LH release

Question 3

what happens in luteal phase if implantation doesn’t occur?

Answer 3

endometrium is shed

Question 4

define infertility

Answer 4

inability to conceive after 1 year of regular unprotected sex

Question 5

what can infertility be due to?

Answer 5

• primary gonadal failure (high GnRH and LH/FSH but no inhibin/testosterone)
• hypo/pituitary disease (low FSH/LG and no inhibin/testosterone)

Question 6

what are the clinical features of male hypogonadism?

Answer 6

• loss of libido
• impotence
• small testes
• dec. muscle bulk
• osteoporosis

Question 7

what are the causes of male hypogonadism?

Answer 7

• hypothalamic-pituitary disease
• primary gonadal disease (Kleinfelter’s, testicualr torsion)
• hyperprolactinaemia
• androgen receptor def

Question 8

what investigations would you carry our for male hypogonadism?

Answer 8

• LH, FSH, testosterone levels
• prolactin
• sperm count
• chromosomal analysis

Question 9

what 2 things do you look for in a sperm count?

Answer 9

• azospermia: absence of sperm in ejaculate

- oligospermia: reduced sperm in ejaculate

Question 10

what is the treatment of male hypogonadism?

Answer 10

• HRT - replace testosterone
• for fertlity - testosterone isn’t enough, give LH/FSH
• hyperprolactinaemia: dopamine agonist to inhibit prolactin

Question 11

where are testosterone/androgens produced?

Answer 11

• leydig cells of testis
• adrenal cortex
• ovaries
• placenta
• tumours

Question 12

what are the main actions of testosterone?

Answer 12

• development of male genital tract
• secondary sexual characteristics
• maintenance of adult fertility
• anabolic effects

Question 13

how much testosterone is protein bound?

Answer 13

98%

Question 14

what 2 enzymes can act on testosterone?

Answer 14

5 alpha reductase turns testosterone into DHT (acts on AR)

aromatase action turns testosterone into 17 beta oestradiol (acts on ER)

Question 15

what are the clincial uses of testosterone?

Answer 15

in adulthood, testosterone will inc:

• lean body mass
• muscle size and strength
• bone formation and mass
• libido and potency

Question 16

what is amenorrhoea? priamry/secondary?

Answer 16

• absence of periods
• primary: failure to begin spontaneous menstruation by 16
• secondary: absence of menstruation for 3 months in a woman that has previously had cycles

Question 17

what is oligomenorrhoea?

Answer 17

irregular long cycles

Question 18

what are the causes of amenorrhoea?

Answer 18

• pregnancy or lactation
• ovarian failure
• gonadotrophin failure
• hyperprolactinaemia
• androgen excess

Question 19

what investigations should be done with someone with amenorrhoea?

Answer 19

• pregnancy test
• LH, FSH, oestradiol, androgen blood test
• day 21 progesterone (can tell if women ovulated in previous cycle)
• prolactin, thyroid function tests
• chromosomal analysis
• ultrasound scan

Question 20

what is the treatment for amenorrhoea?

Answer 20

• treat the cause
• primary ovarian failure (infertile so HRT)
• Hypo/pit disease (HRT for oestrogen replacement and gonadotrophins for fertility treatment)

Question 21

what is PCOS associated with?

Answer 21

• inc. CVS risk

- insulin resistance

Question 22

what does the diagnosis of PCOS require?

Answer 22

2 of:

• polycystic ovaries on ultrasound
• irregular or no ovulation
• androgen excess

Question 23

what are the clinical features of PCOS?

Answer 23

• hirsutism
• menstrual cycle disturbance
• inc. BMI

Question 24

what is the treatment of PCOS?

Answer 24

• metformin
• clomiphene
• gonadotrophin therapy

Question 25

what is clomiphene?

Answer 25

• oestrogen-antagonist
• binds to oestrogen receptors in hypothalamus
• blocks normal -ve feedback
• results in inc. GnRH and gonadotrophin secretion

Question 26

what are the causes of hyperprolactinaemia?

Answer 26

• dopamine antagonist drugs (anti-emetics, anti-psychotics)
• prolactinoma
• stalk compression due to pituitary adenoma
• PCOS
• primary hypothyroidism
• oestrogens, pregnancy and lactation

Question 27

what are the clinical features of hyperprolactinaemia?

Answer 27

• galactorrhoea
• hypogonadism
• prolactinoma (headache and visual field defects)

Question 28

what is the treatment of hyperprolactinaemia?

Answer 28

• treat cause
• dopamine agonists (cabergoline, bromocriptine)
• prolactinoma (DA agonists, pituitary surgery)