lecture 9: menopause Flashcards
1
Q
What is the menopause?
A
- The menopause is the final menstrual period
- the average age of menopause is around 51-52 years (age range 48 - 55 years)
- defined retrospectively after 12 months of absent periods
2
Q
What is perimenopause?
A
- climacteric, menopause transition
- the period when ovarian function declines, cycles are irregular and menopausal symptoms appear
- begins mid to late forties, ends one year after menopause
- lasts for years
3
Q
What is post menopause?
A
- is the whole of women’s life after menopause
- no periods, no ovulation, hormones low, cannot conceive
4
Q
What is early menopause?
A
- 40 - 45 years
- 5%
5
Q
What is premature ovarian insufficiency?
A
- premature menopause
- menopause prior to 40 years
- 1%
6
Q
In what ‘state’ does a woman spend a lot of her life?
A
- postmenopause
7
Q
How many women can expect to reach the menopause?
A
- 95% of women
- female life expectancy has increased while age of menopause has remained constant
- around a third of our life is spent beyond the menopause
8
Q
What is the aetiology of menopause?
A
- loss of ovarian follicular activity at menopause
- decline in quantity and quality in the years preceding
9
Q
How many eggs are in the ovary?
A
- atresia (degeneration) of ovarian follicles (eggs) during the lifespan
- foetus at 20 weeks’ gestation
- each ovary contains about 5 million follicles
- term
- 1-2 million follicles
- puberty
- 300 000 - 400 000
- 37 years
- 100 000, then rapid loss
- perimenopausal threshold
- <1000 follicles?
- also a decline in quality of the follicles
- the follicles are not lost just through ovulation
- the vast majority of follicles are lost through atresia and apoptosis
10
Q
What is the age related decline in follicle numbers?
A
11
Q
What are factors regulating the age at natural menopause?
A
- poorly understood
- not influenced by race, age of menarche, parity, OCP
- genetic factors – are important
- cigarette smoking
- menopause is 1 - 2 years earlier
- surgical history
- hysterectomy may reduce the age at menopause by around 3 - 4 years
- may be due to impairment of the ovarian blood supply
12
Q
What is the aetiology of premature menopause (POI)?
A
- idiopathic
- karyotypically normal
- spontaneous POI (1%)
- iatrogenic
- surgery/chemo/radiotherapy (8 - 19% of women under 40)
- rare causes:
- galactosaemia (excess milk products, galactose is stored in the ovaries and is toxic to oocytes)
- auto-immune
- auto-immune
- genetic
- turner’s syndrome
- fragile x syndrome
13
Q
What chromosomal abnormalities can affect ovarian function?
A
- deletion in X chromosome between positions 13 and 26 can affect ovarian function
14
Q
What are physiologic changes associated with reproduction?
A
- hypothalamus becomes activated around puberty with pulsatile release of GnRH
- causes release of LH and FSH in a pulsatile manner from the anterior pituitary
- FSH affects the ovaries
- binds to granulosa cells and grows follicles
- follicles produce oestrogen
- results in secondary sexual development (eventually menstruation)
- LH binds to theca cells (stroma around the follicles)
- results in androgen production
15
Q
What is the ovarian follicle?
A
- secondary oocyte
- corona radiata
- cumulus oophorus
- antrum
- granulosa cells
- theca interna
- theca externa
produce oestrogen, activin, inhibin, follistatin, AMH