PCOS & Subfertility (Mx) Flashcards
(42 cards)
What is the Rotterdam Criteria for PCOS?
At least 2:
- Oligo/anovulation (>2 years)
- Clinical or biochemical features of hyperandrogenism
- Cysts on USS
What are the requirements for cysts on USS for PCOS?
> =12 in one/both ovaries measuring 2-9mm or ovarian volume >10cm3
What is the approach for PCOS management outside of pregnancy/ not planning on pregnancy?
Lifestyle
Hormonal
Symptomatic
What is the lifestyle management for PCOS?
- Weight reduction
- Dietary modification (consider referral to dietician)
- Screen for T2DM and cardiovascular disease
What is the hormonal management for PCOS?
- COCP
- Cyclical oral progesterone
- Levonogestrel IUS
What is the mechanism of hormonal treatment in PCOS?
Increases sex hormone binding globulin which helps relieve androgenic symptoms
&increases progesterone (not produced by CL during anovulation) causing withdrawal bleed (regular periods) and protects against unopposed oestrogen
What is the management for PCOS if there are too many risk factors for COCP?
3 monthly progesterone to induce withdrawal bleeds (should take place every 3-4 months) & protect endometrium
What is the symptomatic management for PCOS?
- Topical eflornithine cream (hirsuitism)
- Co-cyprindiol
- Cyproterone acetate
- Metformin
- GnRH analogues
- Surgical treatment (laser or electrolysis)
When would co-cyprindiol be used for PCOS?
When it’s complicated by hirsutism and acne (also acts as a contraception)
Cyproterone acette + ethinyloestradiol
What is the mechanism of cyproterone acetate?
Antiandrogen
When are GnRH analogues used in PCOS?
When women are intolerant of other therapies
What is the managment of PCOS for subfertility?
- Encourage weight loss
- Clomiphene (1st line for women with normal BMI)
- Gonadatrophins
- Laprascopic ovarian drilling
When would metformin be added to clomiphene for PCOS subfertility?
After 3 failed cycles with clomiphene
What is the risk with gonadatrophins?
Ovarian hyperstimulation syndrome
What is laparoscopic ovarian drilling?
Destroys the ovarian stroma and may prompt ovulatory cycles
Describe the hormonal changes in the first part of the follicular phase?
- LH and FSH released from the anterior pituitary
- LH attaches to theca cells and causes androstenedione production
- FSH attaches to the granulosa cells and causes aromatase production
- Aromatase catalyses formation of 17beta oestradiol from androstenedione
- 17beta oestradiol negatively feeds back to the pituitary and reduces predominantly FSH (to prevent more than one follicle developing)
Describe the hormonal changes midway through the follicular phase?
- Granulosa cells in the dominant follicle increase LH receptors
- Increased 17beta oestradiol produced
- Levels of 17beta oestradiol exceed the threshold and now positively feedback onto the hypothalamus
- Positive feedback predominantly increases LH secretion, causing an LH surge and release of the oocyte from the follicle
(Luteal phase begins)
What are the hormonal changes in PCOS?
- Anterior pituitary secretes too much LH
- Increased circulating androstenedione
- Travels into the blood and converted to oestrone by aromatase in peripheral tissues
- Negative feedback to the pituitary, predominantly suppresses FSH production resulting in a 2:1 LH:FSH
- No LH surge (high levels of baseline LH) meaning follicles don’t rupture and form cysts
What are the symptoms of PCOS?
Hyperandrogenism
- Male pattern baldness
- Acne (face, back, chest)
- Hirsutism (upper lip, chin, chest)
Anovulation
- Amenorrhea
- Oligomenorrhea
Insulin resistance
- Overweight/ obese
- Acanthosis nigricans
What is the mechanism of raised testosterone in PCOS?
- Increased insulin can inhibit SHBG, increasing amount of free testosterone
- Increased LH causes increased androstenedione which can be converted to testosterone by 17beta-hydroxysteroid dehydrogenase (produced by granulosa cells)
What is the mechanism of clomiphene improving fertility in PCOS?
Selective oestrogen receptor modulator
- Blocks oestrogen receptors in hypothalamus
- No negative feedback, predominantly increasing FSH secretion (normalising LH:FSH ratio)
- Normalised ratio, increases follicle development
- Dominant follicle producing oestrogen causes positive feedback, increasing predominantly the LH secretion and leading to an LH surge causing ovulation
What is the mechanism of cyproterone acetate?
Antiandrogen
- Blocks androgen receptors to reduce hirsutism and scalp hair loss
Decreased androgen production
- Progestogenic effects decrease LH secretion from pituitary (decreased androstenedione production)
Why do progesterone treatments work for PCOS?
Anovulation leads to decreased progesterone from the corpus luteum –> amenorrhea, oligomenorrhea (and increased unopposed oestrogen)
Taking progesterone maintains the uterine lining and causes a withdrawal bleed (pill free interval)
Protective against unopposed oestrogen (endometrial cancer) and can increase SHBG which relieves androgenic sx
What is the most successful biomarker for ovarian reserve?
Anti-mullarian hormone
Produced by granulosa cells and doesn’t change in response to gonadotrophins
