What is an immature egg?

When talking to one of our embryologists, you may hear the term “immature egg” while discussing your fertilisation results. So, what is an immature egg exactly?

An immature egg is an oocyte that has not reached meiotic competency, which means it has not reached the first stages of meiotic division. For normal fertilisation to occur, the egg needs to have the correct number and arrangement of chromosomes.

When an egg is immature, it is not capable of fertilising and will not be injected or inseminated. It is normal to have approximately between 10-15% of immature eggs in one oocyte recovery, however it is possible to see more in some patients.

This is another reason why timing is so essential to your fertility treatment: the time you take your trigger injection and the time you have your egg collection or treatment. We want to maximise your chances of having a successful egg collection and excellent fertilisation rate and most of all, a successful pregnancy.

For more information on how we can help you contact our clinic on 02 9586 3311 or email us at fert1@fertilityfirst.com.au


Nic Stark

Nic Stark is Fertility First's Senior Research Embryologist. She holds a Masters of Reproductive Health Sciences and Human Genetics, a Bachelor in Medical Science, and is completing her PhD in Medicine (Reproductive Physiology). She has been an embryologist for over 15 years.

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