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Sperm cells swimming toward an egg to fertilise

24/10/2023 - 3 min read

What happens after your egg collection?

Care Team

Following egg collection, what will happen in the embryology laboratory?

For most patients once eggs have been collected, they will be fertilised in the laboratory with your partners sperm, and in some cases with donor sperm.

The collected eggs need to be mature to be able to be fertilized. So it is important to realize that only mature eggs will be able to accept a sperm and you may get some eggs which are mature and some which are not. Insemination may be with "standard insemination" by placing the sperm with the eggs or using ICSI. We often use the ICSI technique for patients who have sperm issues. Only mature eggs will be able to fertilize by either technique. So it is important to realize that not all the eggs collected at the egg collection will have the ability to fertilize.

Once the eggs are inseminated they will be placed in our laboratory culture system. The following day we will know how many eggs have fertilised to form the initial numbers of embryos to take you to the next stage of your journey. At this stage the embryology team will call you to let you know how many eggs have fertilised to form early embryos.

The next very important step is to find out which of the early embryos are the strongest. These early embryos will therefore be cultured in the laboratory following the egg collection. At this stage some of the embryos should have started to grow and increase the number of cells inside them. It is important to realize that not all the early embryos will grow. At this early stage if you have sufficient embryos of good quality the embryology team may recommend extending  the culture beyond this early stage to  4, 5 or even 6 days after the egg collection. This extended, or Blastocyst culture, as it is known, allows the strongest embryos to self select and identify themselves as the most likely to result in a pregnancy. It is also important to realize that not all embryos will proceed to this stage - this is entirely normal and part of the process of identifying the best and strongest embryo or embryos for transfer or freezing for treatment in the future. At Care, we also provide our CareMaps-AI time-lapse incubation powered by Artificial Intelligence to select embryos.

Rest assured our expert embryology scientific team will be available to update and advise you on the progress and the best plan for your embryos.

Depending on the number and quality of your embryos the next step is the embryo transfer which will take place on days 4, 5 or 6 after the eggs are collected. This plan may be modified depending on your individual circumstances, the number of embryos available and if any of our cutting edge technologies - such as Pre-implantation Genetic Testing of embryos (PGT-A) have been recommended by your Consultant.