IVF Step By Step - Step Two
The second stage in the IVF process involves removing the eggs from your body and fertilising them with sperm in a laboratory.
You've been receiving medication for the last 12 days or so to encourage the growth of the follicles in your ovaries. Each of these follicles contains an egg. Once your fertility doctor is sure that the follicles have grown to an appropriate size, you'll be given an injection of hCG to force these eggs to mature and be ready for collection. The hCG also loosens the attachment of the eggs to the walls of the follicles, making the eggs easier to remove.
The collection of the eggs, sometimes referred to as ‘egg retrieval', is timed to take place three days after the hCG injection is administered. The procedure is carried out in a fertility clinic. Usually you would be kept awake but you'll probably be given a sedative and perhaps a local anaesthetic applied in the vagina. You may feel some discomfort during the procedure but many women report that it's not painful.
Using an ultrasound device as a guide, the person carrying out the procedure will insert a needle through the top of your vagina. The needle will be used to suck out the fluid in the each of the follicles, taking the egg in each follicle with the fluid. The fluid is then put under a microscope to check whether or not it contains an egg (normally, around 80 % of the follicles will have eggs in them).
The process of collecting eggs usually takes around 30 minutes to complete, depending on your clinic's methods. Afterwards, you'll probably be advised to stay and rest for a while, and to take it easy for the rest of the day.
Preparation for fertilising the eggs begins on the same day on which the eggs are removed from your ovaries...
If you are using your partner's sperm and not sperm from a donor, your partner will need to provide a sample of sperm at the time of egg collection. Bear in mind that your partner will probably be advised to avoid all sexual activity including masturbation for three days before he gives the sample.
Now the sperm sample is ‘washed'. This basically means that the sperm cells are removed from the semen (which is actually the name for the fluid that contains the sperm cells, not for the sperm itself). Your fertility doctor may decide, in consultation with you, to select only sperm cells which appear to be healthy and well-formed.
Egg Incubation And Fertilisation
In the meantime, your eggs will have been incubated. They are kept this way for up to eight hours before they are fertilized. When the time comes for fertilisation, the eggs are put into a glass container, typically a Petri dish, where they are combined with the sperm cells. In some cases, if the sperm has difficulty penetrating and fertilising an egg, a technique known as ICSI may be used, whereby the sperm is injected directly into the egg.
The following day, the eggs will be checked to see if they have been successfully fertilised. Two or three days later, the eggs which have been fertilised (now called ‘embryos') will have begun dividing into cells. Those embryos that appear viable will be the ones selected for insertion into your uterus. The number of embryos inserted will depend on your own health situation and age, as well as legal considerations.
Chances Of Pregnancy
If 70 to 80 % of the retrieved eggs are fertilised the fertilisation procedure is considered successful. The chance of pregnancy resulting from any one cycle of IVF is 15 % in the UK.