What is IVF?
IVF is the technique of mixing the women’s eggs with sperm in a small dish or test-tube in the laboratory to allow fertilisation to occur. Once the eggs are fertilised, one or more developing embryos are replaced into the woman’s womb through the cervix.
Who needs IVF?
Many cases of infertility can be helped with IVF. However, the chances of pregnancy are very variable and depend on the cause of your infertility. When you are seen at the clinic we will discuss the most suitable type of treatment for you and give you an estimate of your chance of becoming pregnant.
For most couples, IVF treatment involves using your own sperm and eggs. Some patients have treatment with donated eggs or sperm but of course this would never be done without your consent.
What does IVF involve?
The precise details of your treatment will be sent separately and below is a short outline of the steps involved in IVF. These include:
- Stimulation of the ovaries
- Monitoring of egg development
- Egg collection
- Sperm preparation
- Fertilisation
- Embryo replacement
- Pregnancy test and scan
Stimulation of the ovaries
In a natural menstrual cycle, a woman produces only one egg, but to increase the chances of pregnancy in IVF it is useful to stimulate the ovaries to produce several eggs. This is done by giving you injections for about three weeks to control your natural cycle. Then additional injections are given for about 12 days to make the eggs grow. The eggs need to be mature when they are collected, so their development must be carefully monitored. The drug treatment varies slightly to suit your circumstances but this will be fully discussed with you beforehand.
Monitoring of egg development
Development of the eggs is monitored by two methods. First, the size and number of egg follicles growing in the ovary are observed by ultrasound scanning. The scan is obtained by passing a small device (called a transducer) into the vagina to provide a clear picture of the ovaries on a screen.
The second method of monitoring is by measuring the hormones produced in the ovaries. This is done by a blood test. The blood test may sometimes be needed during the two weeks before egg collection. At least three eggs must be growing before we can proceed to egg collection, so sometimes treatment will fail at this stage.
If the simulation treatment has been successful, the eggs will be mature at the right time and a final, different injection will be given to complete the maturation. Egg collection will be planned for about 36 hours after this injection.
On rare occasions a complication of this treatment can occur (Hyperstimulation Syndrome). The ovaries may become large and painful and if severe, admission to hospital may be necessary. This usually only occurs if you become pregnant, and gets better within a few weeks.
Egg collection
Eggs are collected from the ovary by suction through a fine needle. This needle is inserted into the ovary through the vagina using the ultrasound picture as a guide. Only a mild sedative is needed and you can go home a few hours later.
We hope to obtain at least three eggs, but usually larger numbers are obtained.
Sperm preparation
A fresh sperm sample is needed for IVF so that the sperm are of good quality. The sperm are specially prepared so that only the best, cleaned sperm are put with the eggs.
Fertilisation
After collection, the eggs will be put into an incubator for a short time. A relatively small number of sperm are then added to each egg. The eggs will be looked at the next day to see if fertilisation has occurred. They will then be kept in the incubator for up to six days from the day of egg collection. We monitor them and we will keep in touch with you to let you know when to attend for embryo replacement.
Embryo replacement
We will have previously discussed with patients how many embryos should be replaced. The chance of pregnancy increases with the number of embryos replaced, but so does the risk of multiple pregnancy. There is an increased chance of losing one or all of the babies in a multiple pregnancy. There is an increased chance of losing one or all of the babies in a multiple pregnancy, so we would like to avoid this complication. Therefore, normally only one embryo is replaced.
A maximum of two embryos are replaced except in exceptional circumstances, such as women over the age of 40 years. The procedure for replacement of the embryos is virtually painless and is little more than an internal examination. You will not need to lie down afterwards and you can return to normal (but not too strenuous) activity.
In some circumstances, it may be possible to consider freezing and storing embryos.
Pregnancy outcome
You will have a pregnancy test in two weeks’ time. If this is positive, a scan will be performed five weeks after egg collection to confirm that this is a good pregnancy, and a baby is growing.
Remember that if two embryos are replaced, there is a significant risk (over 25%) of twins. More problems occur with babies from multiple pregnancies and the risks to the mother is also higher.
Miscarriage can occur in any pregnancy but there is also no increased or decreased risk after IVF. There is a small chance (7%) that the pregnancy may stick in the tube (ectopic pregnancy). If this occurs an operation is required to remove the pregnancy and possibly the tube as well.
We see everyone who becomes pregnant regularly at the hospital until we are sure that the pregnancy is growing normally.
