Definition of PCOS
A common disorder often complicated by chronic anovulatory infertility and hyperandrogenism with the clinical manifestations of oligomenorrhoea, hirsutism and acne. Many women with PCOS are obese and have a higher prevalence of impaired glucose tolerance, T2DM and sleep apnoea than the general population.
What is the prevalence of PCOS
One of the most common endocrine disorders in women of reproductive age, however due to differences in diagnostic criteria, prevalence ranges from 2.2-22% (prevalence higher according to the Rotterdam criteria)
How can PCOS be diagnosed
According to the Rotterdam criteria (with two out of three of the following criteria being met):
* Polycystic ovaries (12 or more follicles or increased ovarian volume >10cm3)
* Oligo-ovulation or anovulation
* Clinical and/or biochemical signs of hyperandrogenism
* Hirsutism characterised by excess fascial and body hair and midline hair growth.
* Free androgen index (free and total androgen levels >5 nmol/l can also be used)
* Signs of virilisation (deep voice, reduced breast size, increased muscle bulk)
What needs to be ruled out before diagnosis
alternative causes of irregular cycles (thyroid dysfunction, acromegaly, hyperprolactinaemia) and hyperandrogenism (CAH, androgen secreting tumours)
Most common age of presentation of PCOS
15-35 years old
What is the pathophysiology of PCOS
What is the common presentation of PCOS
What are some complications of PCOS and how can we screen for them
2x increased risk of developing gestational diabetes compared to the general populations- women with PCOS should be offered screening with OGTT at 24-28 weeks gestation
Insulin resistance (present in around 65-80% of women with PCOS, independent of obesity but exacerbated by weight gain)
* Women presenting with PCOS who are overweight (BMI ≥ 25 kg/m2 ) and women with PCOS who are not overweight (BMI < 25 kg/m2 ), but who have additional risk factors such as advanced age (> 40 years), personal history of GDM or family history of T2DM, should have a 2-hour post 75 g OGTT
* In women with impaired fasting glucose (fasting plasma glucose level from 6.1 to 6.9 mmol/l) or impaired glucose tolerance (plasma glucose of 7.8 or more but less than 11.1 mmol/l after a 2-hour OGTT), OGTT should be performed annually
Sleep apnoea- prevalence is further increased with obesity
* Women or partners of women with PCOS should be asked about snoring and daytime fatigue (CPAP therapy improves insulin therapy in affected women)
CVD- lifetime risk is higher in women with PCOS and is mostly preventable
* Should be assessed for CVD by assessing individual CVD risk factors (obesity, lack of physical activity, cigarette smoking, family history of type II diabetes, dyslipidaemia, hypertension, impaired glucose tolerance, type II diabetes)
* BP should be measured at the time of diagnosis and during oral contraceptive therapy
Mental health issues:
* Psychological issues should be considered in all women with PCOS. Depression and/or anxiety should be routinely screened for and, if present, assessed
* Screen for depression and anxiety
Predisposition to endometrial hyperplasia and cancer- good practice to recommend treatment with progestogens to induce a withdrawal bleed at least every 3 to 4 months
* TVUSS should be considered in the absence of withdrawal bleeds or abnormal uterine bleeding
* In PCOS, an endometrial thickness of less than 7 mm is unlikely to be hyperplasia. A thickened endometrium or an endometrial polyp should prompt consideration of endometrial biopsy and/or hysteroscopy.
* There does not appear to be an association with breast or ovarian cancer and no additional surveillance is required
Investigations of PCOS
History and relevant screening (as above)
Bloods for diagnosis and exclusion of alternative pathology:
* Testosterone, SHBG, DHEAS, Free-androgen index, LH, FSH (raised LH:FSH ratio), Prolactin (may be normal or mildly elevated), TSH
OGTT
Imaging- PELVIC USS:
* Polycystic ovaries present in 75% of women with PCOS but also seen in up to 25% of normal women
* TVUSS gives higher resolution images than transabdominal
* Will see 12 or more follicles or increased ovarian volume >10cm3
* Can also assess endometrial thickness (should be done after first withdrawal bleed in women starting progestogens)
* Follicles may be arranged around the periphery of the ovary, giving a string of pearls appearance
What lifestyle advice can be given to women with PCOS
Initial management involves diet, exercise and weight loss (lifestyle change) , which should precede and/ or accompany any pharmacological treatment
* In the general population, motivational interviewing and established behaviour techniques appear more effective than traditional advice giving for changes in weight, diet and/or exercise
* Women should have regular monitoring for weight change and excess weight (minimum 6-12 monthly)- should also have BP monitoring at this time.
How can metabolic dysfunction be treated in PCOS
Treatment of oligomenorrhoea/amenorrhoea in PCOS
COCP or Cyclical oral progesterone (such as medroxyprogesterone) – if amenorrhoea/dysfunctional uterine bleeding. This increases sex hormone-binding globulin which helps relieve androgenic symptoms. Regulates the withdrawal bleed (should take place at least every 3-4months)
How can the risk of endometrial cancer be reduced in women with PCOS
To reduce the risk of endometrial cancer (women with PCOS are predisposed due to obesity, T2DM, IR and amenorrheoa)
* Mirena coil for continuous endometrial protection
* Inducing a withdrawal bleed every 3-4 months with cyclical progestogens or COCP
* oVUSS should be conducted after this first withdrawal bleed
Treatment of anovulation in PCOS
Treatment of hyperandrogenism in PCOS
Pathophysiology of endometrial cancer in PCOS
Under normal circumstances, the corpus luteum releases progesterone after ovulation. Women with PCOS do not ovulate (or ovulate infrequently), and therefore do not produce sufficient progesterone. Consequently, the endometrial lining continues to proliferate under the influence of oestrogen, without regular shedding during menstruation. This is similar to giving unopposed oestrogen in women on hormone replacement therapy. It results in endometrial hyperplasia and a significant risk of endometrial cancer