The Biology Of Fertility Control

Question 1

How fertile are men?

Answer 1

Men are continuously fertile

Question 2

Why are men continuously fertile?

Answer 2

Due to relatively constant levels of pituitary hormones

Question 3

How fertile are women?

Answer 3

Females fertility is cyclical usually restricted to 1-2 days immediately following ovulation

Question 4

When are females most likely to conceive?

Answer 4

In a fertile period which is approximately six days around the time of ovulation

Question 5

How can the time of ovulation be estimated?

Answer 5

• by the number of days after menstruation
• slight rise in body temperature on the day of ovulation
• the thinning of cervical mucus

Question 6

How does female infertility happen?

Answer 6

Due to Failure to ovulate

Question 7

How can female infertility be treated?

Answer 7

With drugs which mimic FSH and LH

Question 8

What can these drugs cause?

drugs which mimic FSH and LH

Answer 8

• super ovulation

Question 9

What can super ovulation result in?

Answer 9

• multiple births

* used to collect ova for in vitro fertilisation (IVF) programmes

Question 10

What else can drugs be given for?

Answer 10

Given to prevent the negative feedback effect of oestrogen on FSH secretion

Question 11

What is artificial insemination useful for?

Answer 11

If the male has a Low sperm count

• several samples of sperm are collected over a period of time

Question 12

If a partner is sterile what can be used?

Answer 12

A donor

Question 13

What is in vitro fertilisation (IVF)?

Answer 13

• Is when ova are surgically removed from the ovaries after stimulation by hormones
• ova are then mixed with sperm in a culture dish
• fertilised eggs are incubated until they have formed at least 8 cells and are then transferred to the uterus for implantation .

Question 14

What does artificial insemination involve?

Answer 14

• Collecting several samples of semen over a period of time.
• It is useful if the male has a low sperm count

Question 15

How can intracytoplasmic sperm injection (ICSI) used during ?

Answer 15

• IVF if mature sperm are defective or low in number

* The head of the sperm is drawn into a needle and injected directly into the egg to achieve fertilisation

Question 16

What is pre-implantation genetic screening (PGS) used for?

Answer 16

To check embryos for single gen disorders and chromosomal abnormalities

Question 17

What is pre-implantation genetic diagnosis(PGD) used for?

Answer 17

Used to check for a known chromosomal or gene defect

Question 18

Why do people support PGD and PGA?

Answer 18

Offers reassurance to couples who are at a high risk of having a child with a genetic disease
Some of these people would choose to remain childless without the help of PGA and PGD

Question 19

What is a great benefit to society as a whole?

Answer 19

A reduced frequency of genetic diseases and disorders

Question 20

Why do people oppose to PGS and PGA ?

Answer 20

It is morally wrong to interfere with conception

They argue that these procedures are the start of eugenics-selective breeding in humans and lead to designer babies

Question 21

What physical methods of contraception are there?

Answer 21

• Barrier methods

* avoiding fertile periods

Question 22

What are barrier methods ?

Answer 22

They use a device to physically block the ability of sperm to reach the ova

Question 23

Give examples of barrier methods

Answer 23

Condom
Diaphragm
Cervical cap 
Intrauterine device (IUD)
Sterilisation

Question 24

What are chemical contraceptives based on?

Answer 24

Based on combinations of synthetic hormones that mimic negative feedback preventing the release of FSH/LH

Question 25

What does the morning-after pill do?

Answer 25

Prevents implantation

Question 26

What does the progesterone-only pill do?

Answer 26

Causes thickening of cervical mucus