57.5 Control of Fertility and Infertility

Question 1

What can cause infertility in females?

Answer 1

• 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).

Question 2

What axis control fertility?

Answer 2

HPG (Hypothalamo-pituitary-gonadal)

Question 3

Which hormone is released from the hypothalamus in the HPG axis?

Answer 3

GnRH (gonadotroph-releasing hormone)

Question 4

What are three physiological states where ovulation can be suppressed?

Answer 4

• Starvation
• Severe exercise
• Emotional stress

Question 5

What are some causes of precocious (early) puberty?

Answer 5

• 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

Question 6

What are some causes of delayed puberty?

Answer 6

• Malnutrition
• Various systemic diseases
• Defects of the reproductive system (hypogonadism)
• Lack of responsiveness to sex hormones

Question 7

What are the effects of puberty for females?

Answer 7

• Menstruation
• Mood changes
• Breast growth
• Pubic hair

Question 8

What are the effects of puberty for males?

Answer 8

• Ejaculation enabled
• Mood changes
• Hair growth on face/armpits/genitalia

Question 9

What are methods of contraception for females?

Answer 9

• Oestrogen/progesterone pills
• Dopamine antagonists
• IUDs
• Female condom
• Surgical methods; cutting fallopian tubes

Question 10

What are methods of contraception for males?

Answer 10

• Condoms
• Vasectomy
• Modulation; heat or CBD to reduce spermatogenesis

Question 11

Describe the process of IVF

Answer 11

• Synchronise ovulation
• Induce superovulation
• Collect eggs under ultrasound
• Fertilise eggs outside of body
• Implant to mother/surrogate

Question 12

What % of oocytes survive to implantation with IVF?

Answer 12

20%

Question 13

How does a spermatogonial transplant treat male infertility?

Answer 13

Spermatogonia transplanted into seminiferous tubules
Tubules get repopulated and mature sperm can be produced

Question 14

What is the treatment for when sperm is functional but somehow not able to fertilise oocyte?

Answer 14

Directly inject sperm into oocyte

Question 15

With faulty sperm a common treatment is…

Answer 15

sperm donation

Question 16

What are the symptomatic effects of menopause?

Answer 16

• Hot flushes
• Vaginal dryness
• Insomnia
• Mood changes
• Infertility

Question 17

Why does menopause occur?

Answer 17

There is a sharp decrease in oestrogen and progesterone production due to oocyte depletion

Question 18

What is the role of FSH in males?

Answer 18

Stimulates sperm production

Question 19

What is the role of FSH in females?

Answer 19

Stimulates follicle development and ovulation

Question 20

What is the role of LH in males?

Answer 20

Stimulates testosterone production (by Leydig cells)

Question 21

What is the role of LH in females?

Answer 21

Stimulates ovulation and progesterone production by ovaries (acts on thecal cells)

Question 22

How is female infertility treated?

Answer 22

IVF

Question 23

What is menopause?

Answer 23

The progressive decline in the female reproductive system

Question 24

What happens during menopause?

Answer 24

• 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).