PCOS Flashcards
long term complications of PCOS
- Subfertility
- Diabetes mellitus
- Stroke & transient ischaemic attack
- Coronary artery disease
- Obstructive sleep apnoea
- Endometrial cancer
definition of PCOS
- Polycystic ovary syndrome (PCOS) is a complex condition of ovarian dysfunction thought to affect between 5-20% of women of reproductive age.
- The aetiology of PCOS is not fully understood. Both hyperinsulinaemia and high levels of luteinizing hormone are seen in PCOS and there appears to be some overlap with the metabolic syndrome
3.
features of PCOS
- subfertility and infertility
- menstrual disturbances: oligomenorrhea and amenorrhoea
- hirsutism, acne (due to hyperandrogenism)
obesity - acanthosis nigricans (due to insulin resistance)
investigations for PCOS
- Pelvic ultrasound: multiple cysts on the ovaries
FSH, LH, prolactin, TSH, and testosterone are useful investigations: raised LH:FSH ratio is a ‘classical’ feature but is no longer thought to be useful in diagnosis. - Prolactin may be normal or mildly elevated.
- Testosterone may be normal or mildly elevated - however, if markedly raised consider other causes
check for impaired glucose tolerance
aietiology + pathophys of PCOS
- The aetiology of polycystic ovary syndrome is poorly understood, and is thought to be multifactorial in origin.
- The two most common hormonal abnormalities present in PCOS are:
- Excess luteinising hormone (LH) – produced by the anterior pituitary gland in response to an increased GnRH pulse frequency.
- This stimulates ovarian production of androgens.
Insulin resistance – resulting in high levels of insulin secretion.
- This suppresses hepatic production of sex hormone binding globulin (SHBG), resulting in higher levels of free circulating androgens.
- Despite the high levels of LH, the increased circulating androgens suppress the LH surge (which is required for ovulation to occur).
- Follicles develop within the ovary, but are arrested at an early stage (due to the disturbed ovarian function) – and they remain visible as “cysts” within the ovary.
risk factors for pcos
Individuals with diabetes, irregular menstruation and/or a family history of PCOS are at an increased risk of developing polycystic ovary syndrome.
differential diagnosis
- Hypothyroidism – obesity, hair loss and insulin resistance.
- Hyperprolactinaemia – oligomenorhoea/amenorrhoea, acne and hirsutism.
- Cushing’s disease – obesity, acne, hypertension, insulin resistance and depression.
investigations
In the UK, the most commonly used diagnostic criteria is the Rotterdam Criteria (2003). It gives a diagnosis of PCOS if two out of three criteria are met:
- Oligo- and/or anovulation
- Clinical and/or biochemical signs of hyperandrogenism
- Polycystic ovaries on imaging - ultrasound finds many ovarian cysts
blood test results in PCOS
- testosterone - raised
- SHBG - low
- LH - raised
- FSH - normal
- Progesterone - low
management of PCOS - Annovulation + Amenorrhea
- Annovulation + Amenorrhea
- An anovulatory menstrual cycles, the effect of oestrogen is unopposed due to lower levels of progesterone.
- This can cause endometrial hyperplasia, which has a risk of becoming malignant.
- Therefore, in amenorrhoeic women, it is important to protect the endometrium from hyperplasia by inducing at least 3 bleeds per year. This can be done by using:
- *Combined oral contraceptive pill (low dose).
- *Dydrogesterone – a progesterone analogue. This is often used if the combined pill is contraindicated.
management of PCOS - Obesity
Weight management in PCOS is vital – achieving a BMI of under 30 may be enough to trigger a regular menstrual cycle.
Advise and encourage a heathy lifestyle, including healthy diet and exercise. This will increase insulin sensitivity. In severe cases, orlistat (pancreatic lipase inhibitor) can be prescribed.
management of PCOS - infertility
- Clomifene +/- metformin helps induce ovulation and is therefore the first line of treatment for women wishing to conceive. However, there is an increased risk of multiple pregnancies, ovarian hyperstimulation syndrome and ovarian cancer (therefore it is limited to use in 6 cycles).
Women with a normal BMI could also benefit from laparoscopic ovarian drilling.
Note: As well as improving insulin sensitivity, Metformin helps with menstrual disturbance and ovulatory function. NICE guidelines recommend Metformin for women trying to conceive with a BMI >25.
management of PCOS - Hirsutism
- Hirsutism can be treated both cosmetically and/or with anti-androgen medication such as cyproterone, spironolactone or finasteride. However, these should be avoided during pregnancy as they are teratogenic.
- Eflornithine is a topical cream that can also be used to help reduce the growth rate of facial hair.
