Disorders of ovulation Flashcards
Causes of Ovulation problems
3 places
hypothalamus
pituitary
ovaries (PCOS)
Problems in the hypothalamus that causes ovulation problems
Kiss1 gene deficiency- rare
GnRH gene deficiency - rare
weight loss/stress related/excessive exercise
anorexia/bulimia
Problems in the pituitary that causes ovulation problems
pituitary tumours (prolactinoma/other tumours) post pituitary surgery /radiotherapy
Problems in the ovaries that causes ovulation problems
Premature ovarian insufficiency
Developmental or genetic causes eg Turner’s syndrome
Autoimmune damage and destruction of ovaries
Cytotoxic and radiotherapy
Surgery
Polycystic Ovarian Syndrome: commonest cause
Oligomenorrhoea
irregular periods
usually occurring more than 6 weeks apart
Polymenorrhoea
periods occurring less than 3 weeks apart
Amenorrhoea
lack of a period for more than 6 months
Primary Amenorrhoea - never had a period (never went through menarche)
Secondary Amenorrhoea -has menstruated before
HIRSUTISM
Excess body hair in a male distribution
Androgen-dependent
PCOS
USS appearance
> /= 10 subcapsular follicules 2-8 mm in diameter,
arranged around a thickened ovarian stroma
not all women with PCOS will have USS appearance
Hormonal abnormalities in PCOS
Raised baseline LH and normal FSH levels. Ratio LH:FSH 3:1
Raised androgens and free testosterone
Reduced Sex Hormone Binding Globin (SHBG)
Oestrogen usually low but can be normal
Hormone Binding Globulin
- Produced by the liver
- Binds testosterone and oestradiol
- If testosterone bound - not converted to active component dihydrotestosterone ie not “free”
- SHBG increased by oestrogens
- SHBG decreased by testosterone thus releasing more free testosterone
Reproductive Effects of PCOS
- PCOS is maybe associated with varying degrees of infertility
- 15% of all causes of infertility is lack of ovulation
- 80% of lack of ovulation due to PCOS
- Associated with increased miscarriages
- Increased risk of Gestational Diabetes
PCOS and Endometrial Cancer
Increased endometrial hyperplasia and cancer
Lack of progesterone on the endometrium
Endometrial cancer associated with type 2 diabetes & obesity
First line treatment
COOC
increases SHBG and thus decreases free testosterone
decreases FSH & LH and therefore ovarian stimulation
regulates cycle & decreases endometrial hyperplasia
BUT may cause weight gain, venous thrombosis, adverse effects on metabolic risk factors
Other treatments of PCOS
Spironolactone (oral tablet)
anti mineralocorticoid and anti androgen properties