Infertility Flashcards
At what 3 steps of the HPG axis can problems occur leading to gonadal dysfunction?
1) Problem with driver - hypothalamic, pituitary
2) Problem with the functional units (follicles) - none, limited, insensitive
3) Problem with the receiver - absent, insensitive, obstructed
What 4 things can go wrong in a female?
1) Puberty sequence
2) Oestrogen dominance
3) Effect of hypoestrogenic status
4) Effect of hyperandrogenic status
What are 5 causes of anovulation?
1) Hypothalamic dysfunction
2) Pituitary dysfunction
3) Thyroid dysfunction
4) Ovarian failure
5) PCOS
Describe PCOS
- In polycystic ovaries, the follicles are not competing, one dominant follicle will present itself (why the cycle is not consistent)
- Need lifestyle interventions (weight loss) which restores ovulation and achieves spontaneous pregnancy
What are the most common causes of ovulatory dysfunction?
1) PCOS (70%)
2) Hypothalamic amenorrhea (10%)
3) Hyperprolactinaemia (10%)
4) Premature ovarian failure (10%)
How does obesity affect fertility?
Obese woman are less fertile, have higher rates of miscarriage and require higher doses of ovulation-inducing agents
How can weight loss be used to treat infertility?
- Weight loss restores ovulation and achieves spontaneous pregnancy
- It is effective and cheap with no side effects and should be the first line of treatment in obese women with anovulatory infertility
What are central obesity and BMI major determinants of?
1) Insulin resistance
2) Hyperinsulinaemia
3) Hyperandrogenaemia
What are problems with ovulation related to the 2 phases of the menstrual cycle?
1) Follicular phase → no egg
2) Luteal phase → transport in tubes, tubal factor - absence/non-functioning of tubes
What medication is used to treat anovulation/infertility?
Clomiphene citrate
How does clomiphene citrate work?
- FSH stimulates ovulation
- Clomiphene citrate stimulates endogenous FSH production
When is clomiphene citrate used?
It is the first line of treatment for those with absent or irregular ovulation but who have normal basal levels of endogenous estradiol
What is laparoscopic ovarian drilling used for?
To treat infertility - drill in 4 places to a depth of 4-10mm on each ovary
- this destroys the stroma and brings down LH
How successful is laparoscopic ovarian drilling?
82% ovulation, 63% conception rate
What are factors/causes of hypogonadotropic hypogonadism?
1) Damage to pituitary gland or hypothalamus from surgery, injury, tumour, infection or radiation
2) Low BMI (<20) - reversible
3) High intensity exercise
4) Certain dietary patterns incl. high fibre, low fat diets
5) Excessive stress
How effective is ovulation induction with gonadotropins?
Cumulative conception rates of 90% for gonadotropin-deficient patients are 6 months of treatment with hMG (human menopausal gonadotropin)
What are complications of gonadotropin therapy (IVF?)?
1) OHSS (ovarian hyper stimulation syndrome) and multiple pregnancies - both caused by multiple follicular development (which can all rupture at once)
2) Anovulatory women with PCOS are particularly prone to multiple follicular development when receiving gonadotropins - so monitor dose using transvaginal scan as need to make sure there is only one dominant follicle (don’t want triplets)
When is ovulation induced with pulsatile GnRH used?
Tailor made for patients who have an intact pituitary gland
Describe ovulation induced with pulsatile GnRH
- An infusion pump, either SC or IV once every 60-90min
- Safe, simple and effective
- Compared with gonadotropin treatment, needs little or no monitoring and low multiple pregnancy and OHSS rate
What are the 2 main causes of hyperprolactinaemia?
1) Prolactin-secreting pituitary gland tumour
2) Use of psychiatric medications
What should all women with hyperprolactinaemia be tested for?
1) Hypothyroidism (TSH and/or thyroid hormones)
2) Pregnancy
What is the choice treatment for ovulation induction in women with hyperprolactinaemia and why?
Dopamine-agonist drugs → Dopamine is the main hormone that controls PRL
→ They directly suppress prolactin production by the tumour and cause an increase in endogenous GnRH secretion, which stimulates the pituitary gland secretion of LH and FSH → induces follicle development and ovulation
How does age affect fertility?
1) Age reduction in fecundity → decrease pregnancy rate, increase miscarriage rate
2) Age-related increase in aneuploidy due to non-disjunction
What is ovarian reserve (OR)?
The number (and quality?) of the follicles left in the ovary at any given time
Why is there declined fertility with age?
1) Germ cells in the female are not replenished during life
2) Attrition and utilisation of follicles leads to a decline in the number of oocytes from birth to menopause
3) The quality of existing oocytes diminishes with age
4) On average, intercourse frequency declines with age