How Are Hormones Used in IVF?
Learn how FSH and LH are used in IVF to mature eggs, followed by fertilisation, embryo development and transfer into the uterus for AQA GCSE Biology.
Hormones are used in IVF to stimulate the maturation of several eggs. The eggs are collected and fertilised with sperm in a laboratory. After the fertilised eggs develop into embryos, one or two embryos are inserted into the woman’s uterus.
Assumption: This explanation is for AQA GCSE Biology Higher Tier because the use of hormones to treat infertility is Higher Tier content. It is not marked as biology-only content.
Which hormones are used?
The main hormones used are:
- FSH (follicle-stimulating hormone): causes eggs to mature in the ovaries.
- LH (luteinising hormone): normally stimulates the release of an egg from an ovary.
FSH and LH can be given as a fertility drug. This may allow a woman to become pregnant through fertilisation inside the body.
In IVF, FSH and LH are used to stimulate the maturation of several eggs rather than just one. Producing several mature eggs gives doctors more opportunities to create viable embryos.
The stages of IVF
- The mother is given FSH and LH so that several eggs mature.
- The mature eggs are collected from her ovaries.
- The eggs are fertilised with sperm in a laboratory.
- The fertilised eggs divide by mitosis and develop into embryos.
- When they are tiny balls of cells, one or two embryos are inserted into the uterus.
- If an embryo implants in the uterus lining, it may develop into a baby.
Disadvantages of IVF
IVF gives someone the chance to have a baby, but it can be emotionally and physically stressful. Success rates are not high, and inserting more than one embryo can cause multiple births. Multiple births increase the risks to both the mother and the babies.
Common exam mistake: Hormones do not fertilise the egg. They stimulate egg maturation; fertilisation during IVF happens outside the body in a laboratory.
