57.5 Control of Fertility and Infertility Flashcards
What can cause infertility in females?
- Age - Corresponds with a decrease in quality and quantity of eggs, particularly when >40.
- Ovulatory Disorders - For example, PCOS or other follicular disorders
- Endocrine System Disorders
- Causes the reproductive hormones (such as progesterone/ oestrogen/LH) to be imbalanced. Could be caused by pituitary cancers or hypopituitarism.
- Tubule Disorders - For example, blocked fallopian tubes. This could be caused by STIs that go untreated, complications from unsafe abortions or postpartum sepsis.
- Uterine Disorders - Could be congenital (e.g. septate uterus), inflammatory (endometriosis) or benign (fibroids).
What axis control fertility?
HPG (Hypothalamo-pituitary-gonadal)
Which hormone is released from the hypothalamus in the HPG axis?
GnRH (gonadotroph-releasing hormone)
What are three physiological states where ovulation can be suppressed?
- Starvation
- Severe exercise
- Emotional stress
What are some causes of precocious (early) puberty?
- Central:
- Damage to the inhibitory system of the brain (due to infection, trauma, or irradiation)
- Hypothalamic cancers producing pulsatile gonadotropin-releasing hormone (GnRH)
- Peripheral:
- Endogenous and exogenous sources of sex steroids
What are some causes of delayed puberty?
- Malnutrition
- Various systemic diseases
- Defects of the reproductive system (hypogonadism)
- Lack of responsiveness to sex hormones
What are the effects of puberty for females?
- Menstruation
- Mood changes
- Breast growth
- Pubic hair
What are the effects of puberty for males?
- Ejaculation enabled
- Mood changes
- Hair growth on face/armpits/genitalia
What are methods of contraception for females?
- Oestrogen/progesterone pills
- Dopamine antagonists
- IUDs
- Female condom
- Surgical methods; cutting fallopian tubes
What are methods of contraception for males?
- Condoms
- Vasectomy
- Modulation; heat or CBD to reduce spermatogenesis
Describe the process of IVF
- Synchronise ovulation
- Induce superovulation
- Collect eggs under ultrasound
- Fertilise eggs outside of body
- Implant to mother/surrogate
What % of oocytes survive to implantation with IVF?
20%
How does a spermatogonial transplant treat male infertility?
Spermatogonia transplanted into seminiferous tubules
Tubules get repopulated and mature sperm can be produced
What is the treatment for when sperm is functional but somehow not able to fertilise oocyte?
Directly inject sperm into oocyte
With faulty sperm a common treatment is…
sperm donation
What are the symptomatic effects of menopause?
- Hot flushes
- Vaginal dryness
- Insomnia
- Mood changes
- Infertility
Why does menopause occur?
There is a sharp decrease in oestrogen and progesterone production due to oocyte depletion
What is the role of FSH in males?
Stimulates sperm production
What is the role of FSH in females?
Stimulates follicle development and ovulation
What is the role of LH in males?
Stimulates testosterone production (by Leydig cells)
What is the role of LH in females?
Stimulates ovulation and progesterone production by ovaries (acts on thecal cells)
How is female infertility treated?
IVF
What is menopause?
The progressive decline in the female reproductive system
What happens during menopause?
- Numbers of oocytes in the ovaries are depleted by atresia and ovarian responsiveness to LH and FSH decreases
- Cycles become anovular and irregular before ceasing altogether
- Oestrogen and progesterone concentrations fall. FSH and LH circulating concentrations are high because of the loss of negative feedback inhibition by oestrogen but no LH surge is seen
- The loss of ovarian steroids results in vaginal dryness, uterine muscle fibrosis, loss of breast tissues, depression, night sweats, hot flushes, increased risk of myocardial infarction, increased bone resorption, and resulting bone weakness
- The changes can be treated with hormone replacement therapy (HRT).
