Endocrine infertility Flashcards
1
Q
What are the clinical features of male hypogonadism?
A
- Loss of libido
- Impotence
- Small testes
- Decreased muscle bulk
- Osteoporosis (testosterone has anabolic action in bone
2
Q
What are the causes of male hypogonadism?
A
- Hypothalamic-pituitary disease
- Hypopituitarism
- Kallmann syndrome
- Illness/underweight - leptin - Primary gonadal disease
- Congenital: Klinefelter’s syndrome (XYY)
- Acquired: testicular torsion, chemotherapy - Hyperprolactinaemia - can inhibit gonadal function
- Androgen receptor deficiency - v rare
3
Q
How is male hypogonadism investigated?
A
- Check LH, FSH, testosterone
- If all low –> MRI pituitary - Prolactin –> check if hyperprolactinaemia
- Sperm count - check no. + motility
- Azoospermia = no sperm in ejaculate
- Oligospermia = reduced - Chromosomal analysis
- Klinefelter’s XYY
4
Q
How is male hypogonadism treated?
A
- Testosterone replacement
- Increases muscle bulk + protects against osteoporosis - S.c. gonadotrophin injections (LH/FSH) for fertility if hypothalamic/pituitary disease
- Induce spermatogenesis - Dopamine agonist if hyperprolactinaemia
5
Q
What are the effects of testosterone replacement?
A
Increases:
- Lean body mass
- Muscle size + strength
- Bone formation + bone mass (in young men)
- Libido and potency
- Does NOT restore fertility
6
Q
What are the adverse effects of testosterone replacement?
A
- Increased risk of CV and metabolic disease in men with multiple cardiovascular comorbidities
- Uncommon: sleep apnoea, acne, breast englargement
7
Q
What is amenorrhoea?
A
Absence of periods
Primary = failure to begin spontaneous menstruation by 16y
Secondary = absence of menstruation for 3 months in a woman who has previously had cycles
8
Q
What are the causes of amenorrhoea?
A
- Pregnancy/lactation
- Ovarian failure:
- Premature ovarian insufficiency (early menopause)
- Oophorectomy
- Chemotherapy
- Ovarian dysgenesis (Turner’s 45XO) - Gonadotrophin failure:
- Hypothalamic/pituitary disease
- Kallmann’s syndrome
- Low BMI
- Post-pill amenorrhoea (downregulates hypothalamus + pituitary)
- Hyperprolactinaemia
- Androgen excess: gonadal tumour
9
Q
How is amenorrhoea investigated?
A
- Pregnancy test
- LH, FSH, oestradiol
- Day 21 progesterone (should rise at ovulation)
- Prolactin
- TFT
- Androgens
- Chromosomal analysis
- Ultrasound scan of ovaries/uterus
10
Q
How is amenorrhoea managed?
A
- Treat cause, e.g. low weight
- Primary ovarian failure - HRT, infertile
- Hypothalamic/pituitary disease - HRT for oestrogen replacement; fertility: gonadotrophins as part of IVF
11
Q
What are the diagnostic criteria for PCOS?
A
2 of the following:
- Polycystic ovaries on ultrasound scan
- Oligoovulation/anovulation
- Clinical/biochemical androgen excess, e.g. increased growth of hair in a male pattern
12
Q
What are the clinical features of PCOS?
A
- Hirsuitism
- Menstrual cycle disturbance
- Increased BMI
13
Q
How is PCOS investigated?
A
- Ultrasound of ovaries (look for cysts)
- Measure androgen levels (excess)
- Examination: increased growth of hair in male pattern
- History - oligoovulation/anovulation
14
Q
How is PCOS treated?
A
- Metformin
- Insulin sensitiser - Clomiphene
- Anti-oestrogenic effect on HPA
- Binds to oestrogen receptors in hypothalamus + blocks -ve fb
- Increase in GnRH + gonadotrophin secretion
- Used in short periods to kickstart HPG axis - Gonadotrophins as part of IVF treatment
15
Q
How is prolactin secretion regulated?
A
- Dopamine (-ve effect) = main hypothalamic hormone controlling prolactin release
- TRH = mild stimulatory effect
