There are 5 steps to a basic IVF cycle:

1. Stop the ovaries functioning normally

Firstly you need to take drugs to stop the production of certain hormones which are produced in the brain and travel to the ovaries to stimulate eggs to grow. This temporarily stops the normal function of the ovaries so we can take control over egg development.

The two main methods of doing this are with GnRH agonist drugs or GnRH antagonist drugs. Both are injections and they both give the same result but some people are more suited to one type over the other. This is something you can discuss with your doctor.

2. Grow multiple eggs simultaneously

Once the ovaries’ normal function has been switched off, there are multiple small follicles approximately the same size, containing immature eggs. Injections of the hormone FSH causes all of these small egg-containing follicles to grow at the same time.

FSH injections will continue until the follicles have grown to their maximum size. The eggs grow at the same time inside the follicles and bigger follicles contain more mature eggs. You will have regular ultrasound scans to ensure to follicles are growing correctly and it is normal for some follicles to grow slightly quicker than the others and reach full size sooner. Only full size follicles contain mature eggs that can be used for IVF and unfortunately any smaller follicles that don’t catch up will likely be wasted.

3. Collect the eggs

When a good number of follicles have grown to full size it is time to schedule the egg collection procedure. You will be asked to take a final ‘trigger’ injection which mimics the hormone surge that causes ovulation in a natural menstrual cycle.

The trigger injection pushes the eggs into the final stages of maturation so the timings are crucial. It takes around 36 hours to fully mature the eggs, but the eggs will be ovulated and released from the follicles into the body at around 38 hours. This means that you must take the trigger injection exactly 36 hours before your procedure time to ensure the eggs are mature but are not lost from the follicles.

A needle is inserted through the wall of the vagina into the ovaries to drain the fluid from each follicle sac where the mature eggs are freely floating around. The fluid is quickly taken to the lab to retrieve the eggs.

4. Make embryos

After the semen sample has been prepared to remove any dead or abnormal sperm, the eggs are inseminated using traditional IVF or by injecting sperm directly into the eggs using ICSI. Only mature eggs have the ability to fertilise and usually around 70% of the mature eggs fertilise normally.

All of the fertilised eggs will be grown in an incubator until the day of embryo transfer. The most common day for transfer is 5 days after fertilisation which is when the embryo would reach the uterus in a natural pregnancy.

5. Transfer or freeze any suitable embryos

An embryo is transferred into the uterus using a fine catheter tube which is passed through the cervix into the correct location for implantation. Hopefully the embryo will implant in the following few days which is confirmed with a pregnancy test around 2 weeks later.

Not all fertilised eggs will grow into good quality embryos. If you have more than one which is suitable for treatment, surplus embryos can be frozen to be transferred in the future without having another egg collection. There is also the option to freeze all of your embryos and wait for a few weeks until all the IVF drugs have cleared from your body before you have an embryo transfer.