2.3. The Biology of Controlling Fertility

Question 1

When are the fertile periods and how can you measure when it is for:

a) Men
b) Women

Answer 1

a) Men are continuously fertile.
b) Females are fertile for a few days each month. There is a period of five days around the time of ovulation where women are most fertile. There is usually a slight rise in body temperature and cervical mucus thickens.

Question 2

Give some reasons for infertility.

Answer 2

• Age
• Genetics
• Disease
• Health and Lifestyle (anorexia, obesity, drug misuse etc.)

Question 3

Female infertility can be caused by the inability to ovulate, how would this come about?

Answer 3

The pituitary gland fails to secrete FSH and LH.

Question 4

How would you treat a woman’s inability to ovulate?

Answer 4

With drugs that mimic LH and FSH or with drugs that interfere with normal negative feedback control blocking oestrogen receptors. This may cause superovulation.

Question 5

What is superovulation?

Answer 5

When a women produces more than one ovum in one cycle.

Question 6

What is artificial insemination?

Answer 6

The collection of semen and the insertion into the woman.

Question 7

What is donor insemination?

Answer 7

Artificial insemination with sperm from a sperm donor.

Question 8

If a man has a low sperm count, what would be a helpful fertility treatment?

Answer 8

Artificial insemination and Intracytoplasmic Sperm Injection.

Question 9

What does IVF stand for?

Answer 9

In-Vitro Fertilisation

Question 10

When would IVF be a suitable fertility treatment?

Answer 10

When a woman has a blocked oviduct.

Question 11

Describe the process of IVF.

Answer 11

Ova are removed from the ovaries of the woman after ovulation is stimulated. Outside the womb, the ova and sperm are mixed and incubated until the zygote becomes a blastocyst. The most suitable embryo is implanted into the uterus. Unused embryos can be used at a later date.

Question 12

Describe the process of ICSI (intracytoplasmic sperm injection).

Answer 12

The sperm is directly inserted into the ovum with a needle.

Question 13

Give some biological reasons for infertility in women.

Answer 13

• Endometriosis
• Ovulation problems
• Poor egg quality
• Tube blockages
• Polycystic ovary syndrome (hormonal imbalance)

Question 14

Give some biological reasons for infertility in men.

Answer 14

• Sperm tube blockages
• Low sperm count
• Sperm allergy

Question 15

How do barrier methods of contraception work?

Answer 15

Prevent sperm being released into the female.

Question 16

Give examples of barrier methods of contraception?

Answer 16

Condoms and cervical caps.

Question 17

What is an intra-uterine device?

Answer 17

A small device (often T-shaped) with copper parts. It is fitted into the uterus to prevent the implantation of an embryo in the endometrium.

Question 18

What is sterilisation? What are the most common methods of sterilisation for both genders?

Answer 18

An often permanent method of contraception which involves surgical procedures. Vasectomy in men, tubal ligation in women.

Question 19

Describe the process of a vasectomy.

Answer 19

Cutting and closing the sperm tube of each testis.

Question 20

Describe the process of tubal ligation.

Answer 20

Cutting and closing each oviduct.

Question 21

How do chemical methods of contraception work?

Answer 21

They contain synthetic versions of oestrogen and progesterone that mimic negative feedback and stop the production of FSH and LH and stop ovulation, implantation or thickening cervical mucus.

Question 22

Give examples of chemical methods of contraception and explain them briefly.

Answer 22

Combination contraceptive pill - Synthetic progesterone and oestrogen which inhibit the secretion of FSH and LH.

Mini pill - Contains synthetic progesterone which inhibits ovulation and causes the thickening of cervical mucus which prevents sperm entry.

Morning-after pill - A high dose of synthetic progesterone and oestrogen which decreases chances of ovulation and implantation. Also thickens cervical mucus.

Question 23

What risks do fertility drugs carry?

Answer 23

The risk of multiple pregnancies. You can also get OHSS (ovarian hyperstimulation syndrome) which is when ovaries become unusually enlarged and fill with fluid.

Question 24

What are the ethics of Pre-Implantation Genetic Diagnostics?

Answer 24

Some support it as it can help identify genetic disorders in children.
Some are against it as it may encourage selective breeding or they believe it’s wrong to interfere with conception.

Question 25

What are some ethics of using fertility drugs?

Answer 25

Should unlimited treatment be available on the NHS?

Could the resources be better allocated elsewhere?

Are IVF and others against commonly held beliefs?