Fertility Specialist Answers Common IVF Questions

In an IVF cycle, it is desirable for several eggs to mature simultaneously, so by suppressing certain hormones it provides the opportunity for several eggs to fully mature – hence increasing the chances of success if one egg were to fail. There are different types of IVF cycles and your fertility doctor will have selected the right cycle type, based on your individual needs. In one type, you start your suppression after you have had your period (it is sometimes called an antagonist cycle) and have already started stimulation, in the other type you may have to do it beforehand (usually known as long down regulation).

In order to create as many eggs as possible from your IVF cycle it is necessary to stimulate the growth of several follicles instead of just one or two. Put simply the more follicles, potentially the more eggs. By having several mature eggs available for attempted fertilisation and transfer – usually between five and 12 – it is hoped that at least one will result in pregnancy. Hormone injections are administered to stimulate the growth of several follicles. The ovaries response to this is monitored carefully by ultrasound and occasionally blood test. The dose and combination of medications are adjusted to suit your individual response.

Once the ultrasounds indicate a reasonable size and number of follicles, the stimulation phase ends and the hormone injections are stopped. A different hormone injection (hcG) is then given, causing final maturation and loosening of the egg from the wall of the follicle.

The egg retrieval occurs on the second morning after this final trigger injection (34 to 36 hours later). It is performed by an ultrasound-guided needle puncture through the top of the vagina. After egg retrieval, you will be issued with medication (progesterone) that will support development of the endometrium (lining of the uterus) in preparation for embryo transfer after fertilisation. The eggs are carefully transferred to the laboratory.

Your partner will be asked to produce his semen sample on the day of your procedure in readiness for fertilisation of the eggs, or, if you use donor sperm a frozen sample will be thawed and prepared.

After the sperm sample is washed and concentrated, it is added to either all or the number of eggs you selected a few hours after retrieval. The eggs are examined the next day for signs of fertilisation. We expect about 60 to 70% of the eggs to fertilise if the sperm sample looks normal. The fertilised eggs are then kept in the incubator for an additional 48 hours. For reference, not every follicle will contain an egg, and not every egg will fertilise, and not every egg that fertilises will go on to form a good-quality embryo.

Two to five days following egg retrieval, the fertilised eggs (embryos) are transferred to the uterus using a fine plastic tube (transfer catheter). The exact number transferred depends on the woman’s individual circumstances, age and embryo quality. This procedure takes only a few minutes and is usually not uncomfortable. You will be shown your embryo before it is placed and can sometimes see the entire procedure on an ultrasound screen.

Any spare embryos that are of good quality can be then be frozen, if desired.

The female now enters the Luteal Phase of her menstrual cycle when the lining of the uterus thickens to provide nutrition for a hopeful embryo implantation and pregnancy to start. This phase generally lasts 12-14 days.

A pregnancy blood test will be carried out about 14 days after embryo transfer to determine whether you have achieved a pregnancy or not. It is important to look after yourself in that time, which is often emotionally charged with expectation and anxiety. If you have been unsuccessful, it is important to discuss the outcome with your doctor and agree on the next steps in your journey.