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11.8 Infertility Treatments

GCSE Biology · AQA · Chapter 11: Hormonal Coordination

A free GCSE Biology lesson for AQA (8461) from OBA School: (Higher tier) Fertility drugs, IVF and the issues they raise. Watch the video, read the explanation and worked examples, then try the revision questions. You can work through the full lesson, with every video, practice quizzes and printable worksheets with mark schemes, in our free online course.

What you will learn

  • Explain how FSH and LH are used in fertility drugs
  • Describe the steps of in vitro fertilisation (IVF)
  • Interpret data on the success of fertility treatment
  • Evaluate fertility treatment from the point of view of patients and doctors, including social and ethical issues

Key words

  • Infertility: Being unable to become pregnant (or to make someone pregnant) after trying for a long time.
  • Fertility drug: A drug containing FSH and LH that stimulates eggs to mature and be released.
  • IVF: In vitro fertilisation: eggs are fertilised by sperm outside the body, in a laboratory.
  • Embryo: A fertilised egg that has divided to form a small ball of cells.
  • Multiple birth: Having twins, triplets or more from one pregnancy.

Why some couples are infertile

This section is Higher tier content. Infertility has many causes. A woman may not ovulate because she makes too little FSH or LH, or her oviducts may be blocked. A man may make too few sperm, or sperm that do not swim well.

Some women can be treated with a fertility drug containing FSH and LH. FSH stimulates eggs to mature and LH stimulates ovulation, so she may then become pregnant in the normal way.

Key fact: Fertility drugs contain FSH and LH – the opposite idea to the contraceptive pill, which inhibits FSH.

In vitro fertilisation (IVF)

IVF can help when fertility drugs alone are not enough, for example if the oviducts are blocked.

  • The mother is given FSH and LH to stimulate the maturation of several eggs.
  • The eggs are collected from the mother and fertilised by sperm from the father in the laboratory.
  • The fertilised eggs develop into embryos.
  • At the stage when they are tiny balls of cells, one or two embryos are inserted into the mother’s uterus.

How successful is IVF?

Success rates are not high and fall steeply with age. The chart shows approximate UK figures.

Worked example: using success rates

A clinic carries out 250 embryo transfers for women under 35. Estimate the number of live births.
32% of 250 = 0.32 × 250 = 80
For women aged 40–42 the same 250 transfers would give 0.11 × 250 = 27.5, so about 28.

Answer: about 80 births (under 35) compared with about 28 (40–42)

Evaluating fertility treatment

  • Gives an infertile couple the chance of having their own baby; Against Emotionally and physically stressful: many injections, procedures and disappointment
  • The baby is genetically related to the parents; Against Success rates are not high, so several cycles may be needed
  • Embryos can be checked for some genetic disorders before transfer; Against Multiple births are a risk to both the babies (e.g. premature birth) and the mother
  • Clinics now often transfer one embryo, cutting multiple births; Against Expensive; the NHS funds only a limited number of cycles

Ethical issues: spare embryos may be frozen, donated to research or destroyed, and some people believe an embryo should have the rights of a person. Others ask whether money spent on IVF should go to other treatments.

Exam tip: In an evaluation, consider the patient (hopes, stress, risk, cost) and the doctor (success rates, safety, number of embryos, ethics).

Common mistakes

  • Saying IVF happens inside the body. Fertilisation happens in the laboratory; only the embryos go into the uterus.
  • Saying the fertilised egg is inserted immediately. It is left to develop into a tiny ball of cells (an embryo) first.
  • Saying fertility drugs contain oestrogen and progesterone. They contain FSH and LH.
  • Saying IVF “usually works”. Most cycles do not lead to a baby, especially for older women.

Revision questions

Try these, then check your answers below each one.

Question 1. (Higher tier) Which hormones are given in fertility drugs to stimulate eggs to mature and be released? (Choose from: FSH and LH, Oestrogen and progesterone, Insulin and glucagon, Testosterone and adrenaline.)

Answer: FSH and LH

Working: FSH makes eggs mature and LH triggers their release.

Question 2. In IVF, where are the eggs fertilised? (Choose from: In a dish in the laboratory, In the oviduct, In the uterus, In the ovary.)

Answer: In a dish in the laboratory

Working: In IVF the eggs are fertilised by sperm outside the body, in the laboratory.

Question 3. True or false? IVF has a high success rate, so most treatment cycles lead to a baby.

Answer: False

Working: False. Success rates are not high, especially for older women; most cycles do not lead to a birth.

Related lessons

Continue in the full course

This lesson is section 11.8 (AGCBH1108) of our free GCSE Biology course for AQA. In the full course you get every video for this section, a self-marking practice quiz, a printable worksheet with a mark scheme, chapter tests, and your progress saved. Go to the full GCSE Biology course.

 

 

 

 

 

 

 

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