In vitro fertilisation (IVF) is just one of several techniques available to help couples with fertility problems to have a baby. Here is how it's done:
The 6-step IVF technique involves removing or harvesting eggs from a woman's body, fertilising them in a laboratory and then placing them back inside the womb after the woman is given hormone drugs in preparation.
One cycle of IVF takes four to six weeks to complete. You and your partner can expect to spend about half a day at your clinic for the egg retrieval and fertilisation procedures. You'll go back two to three days later for the embryos to be transferred to your uterus.
Step 1: suppressing the natural monthly cycle
You are given a drug to administer for about two weeks, either as a daily injection (which is normally self-administered) or a nasal spray.
Step 2: boosting the egg supply
After your natural cycle is suppressed, you are given a fertility hormone called FSH (follicle stimulating hormone). This is usually taken as a daily injection for around 12 days. It will increase the number of eggs you produce, so more eggs can be fertilised. With more fertilised eggs, the clinic has a greater choice of embryos to use in your IVF treatment.
Step 3: checking on progress
The clinic will monitor your progress throughout the IVF drug treatment. This is done by vaginal ultrasound scans and possibly blood tests. You will have a hormone injection to help your eggs mature 34-38 hours before your eggs are due to be collected.
Step 4: collecting the eggs
Eggs are usually collected by ultrasound guidance under sedation. This involves a needle being inserted through the vagina and into each ovary. The eggs are then collected through the needle. Cramping and a small amount of vaginal bleeding can occur after the procedure.
Step 5: fertilising the eggs
Your eggs are mixed with your partner's or the donor's sperm and cultured in the laboratory for 16-20 hours. They are then checked to see if any have been fertilised.
If the sperm are few or weak, each egg may need to be injected individually with a single sperm. This is called intra-cytoplasmic sperm injection (ICSI)
The cells that have been fertilised (embryos) are grown in the laboratory incubator for one to four days before the best one or two are transferred.
After egg collection, you are given medication to help prepare the lining of the womb for embryo transfer. This is given as a pessary (placed inside the vagina), an injection or a gel applied to the skin.
Step 6: embryo transfer
For women under the age of 40, one or two embryos can be transferred. If you are 40 or over, a maximum of three can be used. The number of embryos is restricted because of the risks associated with multiple births.
Remaining embryos may be frozen for future IVF attempts, if they are suitable: more information can be found on the Human Fertilisation and Embryology Authority (HFEA) site.
Some clinics may also offer blastocyst transfer, where the fertilised eggs are left to mature for five to six days and then transferred.
Once pregnancy has been confirmed following IVF, you should have an early ultrasound scan at about six weeks to check that the embryo has implanted in your uterus.
For men: preparing the sperm
Around the time your partner's eggs are collected, you are asked to produce a fresh sample of sperm. The sperm are washed and spun at a high speed, so the healthiest and most active sperm can be selected.
Donated sperm is removed from frozen storage, thawed and prepared in the same way.
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