Fertility Flashcards
What are the four basic conditions required for pregnancy?
o Egg production- anovulation (30%)
o Adequate sperm release-male factor (25%)
o Sperm must reach egg- fallopian tubes (25%), sexual (5%) and cervical (<5%)
o Implantation- often unexplained fertility problems (30%)
What is the physiology of ovulation?
- AMH is produced from small ovarian follicles and reduces the release of oestrogen
- Beginning of the cycle- low oestrogen due to AMH causes +ve feedback on GnRH to stimulate production of LH & FSH
- As follicle grows- AMH production reduces- oestrogen levels increase -ve feedback- reduced LH & FSH production
- Maturing follicles compete for stimulating hormones- only one is large enough with sufficient receptors to survive and grow-dominant follicle
- NB – development of dominant follicle is also co-regulated by inhibin B, also suppresses FSH
- Follicle matures- oestrogen output increases- +ve feedback, increases LH & FSH. LH surge = ovulation
- Follicle becomes corpeus lutuem- produces oestrogen & progesterone to maintain secretory endometrium
- If implantation occurs -hCG is produced by trophoblast tissue, acts on corpus luteum to maintain oestrogen & progesterone production- placental takes over at 8-10 weeks gestation
What is preovulation?
cervical mucus is acellular, will ‘fern’ when on a dry slide and will form ‘spinnbarkeit’ (elastic- like string)
body temperature normally drops 0.2OC and rises 0.5OC in the luteal phase
What are the investigations for ovulation?
o Progesterone levels- elevated serum progesterone in mid-luteal phase suggests ovulation, for women with irregular cycles, repeats progesterone tests may be required
o Ultrasound- serially monitor follicular growth and corpus luteum after ovulation, rarely performed
o Urine predictor kit- indicates LH surge has taken place, ovulation should follow
What is PCOS?
affects around 5% of women and causes 80% of cases of anovulation infertility
o PCO on USS
o Irregular periods >35 days apart
o Hirsutium- clinical (acne/excess body hair) and/or biochemical (raised serum testosterone)
What is a polycystic ovary?
a characteristic transvaginal USS appearance of multiple (>12) small (2-8mm) follicles in an enlarged ovary (>10ml/vol)- found in 20% of all women including those who regularly ovulate
What is the pathology of PCOS?
disordered LH production and peripheral insulin resistance
the combination of raised LH and insulin act synergistically on the PCO to increase ovarian androgen production
raised insulin also acts to increased adrenal androgen production and reduce hepatic steroid hormone-binding globulin leading to increased free androgens
increased intraovarian androgens leads to disrupted folliculogenesis and excess small ovarian follicles causing irregular or absent ovulation
raised peripheral androgens leads to hirsutism
What are the clinical features of PCOS?
typical patient is obese, with acne, hirsuitism and oligomenorrhoea/amenorrhoea
changes in weight over time will alter insulin levels and severity of the syndrome
miscarriage is also more common and may be related to increased levels of LH and/or insulin and increased body weight
What are the investigations for PCOS?
Anovulation is tested with
• FSH- raised in ovarian failure, low in hypothalamic disorders and normal in PCOS
• AMH- high in PCOS, low in ovarian failure
• Prolactin- excludes prolactinoma
• TSH
Hirsutium is tested with serum testosterone levels-
androgen-secreting tumour or congenital adrenal hyperplasia
LH is measured- often raised in PCOS, but not diagnostic
o USS- transvaginal to look for PCO
o Other- screening for diabetes and abnormal lipids
What are the complications of PCOS?
50% of PCOS women develop T2DM in later life
30% develop gestational diabetes, which is reduced by weight reduction
endometrial CA is more common in women with many years of amenorrhoea due to unopposed oestrogen
What are the treatments for PCOS?
o Advice regarding diet and exercise, reduces insulin levels and therefore PCOS symptoms
o COCP if fertility not required- regulates menstruation and treats hirsutism
o Anti-androgens (cyproterone or spironolactone)-treatment for hirsutism, but must not conceive
o Metformin- reduces insulin levels and therefore hirsutism and promotes ovulation
o Eflornithine- topical anti-androgen used for facial hirsutism
What is hypothalamic hypogonadism?
reduction in GnRH causes amenorrhoea due to reduced FSH & LH levels causing reduced oestrogen levels
usually with anorexia nervosa and common in women on diets, athletes and those under stress
restoration of body weight restores hypothalamic function
What is Kallman’s syndrome?
occurs when GnRH-secreting neurones fail to develop
exogenous gonadotrophins or GnRH pump will induce ovulation
bone protection with COCP or HRT is required
What is hyperprolactinaemia?
excess prolactin secretion leads to reduced GnRH release
usually caused by benign tumours (adenomas) or hyperplasia of pituitary cells, but can be associated with PCOS, hypothyroidism and psychotropic drugs
accounts for 10% of anovulatory women who commonly present with oligomenorrhoea/amenorrhoea, galactorrhoea and headaches or bitemporal hemianopia (pituitary tumour)
What is the treatment for hyperprolactinaemia?
treatment with dopamine agonist (bromocriptine or carbergoline) usually restores ovulation because dopamine inhibits prolactin release
surgery may be necessary
