The eggs are placed in a special fluid and stored in an incubator. They will be mixed with sperm from your partner or a donor and left for 16-20 hours to fertilise.
If the sperm count is low or poor quality you and your partner may be offered ICSI (intracytoplasmic sperm injection). The sperm is injected directly into the egg to improve the chances of fertilisation.
Over the next few days, the fertilised eggs turn into embryos. Embryologists will carefully cultivate your embryos for up to 6 days to maximise the chance that they progress through critical stages of development.
Embryos advance through several stages: zygote (fertilised egg) to cleavage stage (an embryo with more than one cell) to morula (a dense ball of small cells) to blastocyst (an embryo with a fluid filled cavity). Blastocyst transfers have the highest pregnancy rate per embryo (implantation rate). The best embryos will be chosen for transfer.