Hormonal Control of Menstrual Cycle and Hormonal Disorders Flashcards
Over-the-counter ovulation predictor tests usually detect which hormone. Why?
OTC ovulation predictor tests usually detect luteinizing hormone as this surges immediately before ovulation.
What occurs during the luteal phase of the menstrual cycle?
After the release of the oocyte, the remaining granulosa and theca cells on the ovary from the corpus luteum (meaning yellow body, due to the yellow pigment of the granulosa cells).
The CL produces VEGF to ensure it has a rich blood supply to enable sustained progesterone production. Progesterone stabilises the endometrium in preparation for pregnancy and inhibits secretion of LH and FSH. This phase lasts 14 days without much variation. Unless b-hCG is produced from an implanted embryo, the CL will regress and progesterone levels will drop. This will destabilise the endometrium and menstruation will follow.
How is amenorrhoea defined?
Absence of periods for 6 months or more in a woman of fertile age (but not due to pregnancy, lactation or menopause) or absence of menarche by 16 years of age.
What is polycystic ovary syndrome?
PCOS is a syndrome of ovarian dysfunction along with the cardinal features of hyperandrogenism and polycystic ovary morphology.
What is the prevalence of polycystic ovaries?
The prevalence of polycystic ovaries seen on ultrasound is around 25% of all women but is not always associated with the full syndrome.
How does PCOS present?
Clinical manifestations include menstrual irregularities, signs of androgen excess (e.g. hirsutism and acne) and obesity.
- Amenorrhoea/oligomenorrhoea (75%)
- Hirsuitism
- Subfertility (75%)
- Obesity (40%)
- Acanthosis nigricans
May be asymptomatic.
What biochemical findings might be seen in PCOS?
Elevated serum LH levels, biochemical evidence of hyperandrogenism and raised insulin resistance are common features.
How is PCOS managed?
Management of PCOS involves the following:
- COCP (regulate menstruation, reduce androgenic symptoms)
- Cyclical oral progesterone (regulate withdrawal bleed)
- Clomiphene (induce ovulation)
- Lifestyle: diet, exercise (reduce risk of diabetes, weight reduction)
- Ovarian drilling (encourage ovulatory cycles)
- Metformin (diabetes, insulin resistance, weight loss, aids ovulation but not pregnancy outcome)
- GnRH analogues
- Surgical intervention (laser or electrolysis)
How is PCOS managed?
Management of PCOS involves the following:
- COCP (regulate menstruation, reduce androgenic symptoms)
- Cyclical oral progesterone (regulate withdrawal bleed)
- Clomiphene (induce ovulation)
- Lifestyle: diet, exercise (reduce risk of diabetes, weight reduction)
- Ovarian drilling (encourage ovulatory cycles)
- Metformin (diabetes, insulin resistance, weight loss, aids ovulation but not pregnancy outcome)
- GnRH analogues
- Surgical intervention (laser or electrolysis)
What treatment options are available for PMS?
Simple therapies: stress, caffeine and alcohol reduction. Exercise, mindfulness,
Alternative therapies: St John’s wort
Vitamins: Isoflavones (red clover), magnesium, calcium, B6
Medical:
- COCP
- Transdermal oestrogen
- GnRH analogues
- SSRI’s (+/- CBT)
True or false: during menstruation, the stratum basalis is shed.
False. The stratum basalis remains while the stratum compactus is shed.
True or false: Diagnosis of PCOS can only be made with biochemical evidence of hyperandrogenism.
False.
Women must have two of three diagnostic criteria:
- Ultrasonic evidence of PCOS
- Clinical or biochemical hyperandrogenism
- Chronic anovulation
True or false: Ultrasonic evidence of polycystic ovaries is present in 25% of women.
True.
True or false: PCOS is an unusual cause of anovulation.
False. PCOS is the most common cause of anovulation.
True or false: PCOS is associated with obesity in 10% of women.
False. More than 40% of women with PCOS are overweight.
