What is epigenetics, and how does it affect egg donation?

Donor egg IVF

In egg donor IVF, a donor's eggs are fertilised with sperm from either the male partner or a sperm donor. After that, the resulting embryos are transferred to the woman's uterus, where she'll carry and deliver the baby.

Your clinic or fertility specialist might recommend egg donor IVF if you:

• aren’t producing eggs of your own because of cancer treatment, premature menopause or ovarian failure. 

• you’ve been told that using your eggs is unlikely to result in pregnancy.

• you have a high risk of passing on a genetic or hereditary condition to your baby.

  
  

What is epigenetics?

You may have heard of “genetics” before. It refers to the unique information stored in our DNA (which is made up of genes) that determines certain qualities or traits passed from parents to offspring. 

Whenever we use our genes, they turn into proteins that help us do all sorts of things like producing hormones, contracting our muscles, making our ovaries grow eggs and ovulate, creating movement for our sperm, and even helping us see images and transport oxygen.

But your health and physical traits aren’t influenced only by your genes. Your behaviour and environment play a part, too. Enter the emerging field of epigenetics.

Epigenetics studies how cells control gene activity without changing the DNA — turning genes “on” or “off”. Even though epigenetic changes aren’t permanent, they can impact how our body interprets and responds to our genetic makeup even before we’re born. 

So, how does epigenetics matter in IVF? Our environment can affect how our genes work from the moment we're conceived. The well-being and behaviours of our mothers during pregnancy, like staying active, smoking, and reducing stress, all impact the environment in which we grow. 

During pregnancy, the mother and the developing embryo exchange information through epigenetics. The mother can control how the embryo uses its genetic material, which affects how the child develops into adulthood. This early nurturing effect can have a lasting impact on the child's development, and the mother plays a significant role in shaping it.

This environment influences the building blocks that shape our physical appearance and health and ultimately affects our future growth and development. Research shows that the embryo’s quality of life inside the womb has a lasting impact on a baby's well-being, making the mother’s uterus the first and most significant environment. 

Think of it as baking a cake: the DNA is the ingredients, while your body is the oven. An oven might not be able to change the ingredients, but it sure can affect how the cake will turn out. It’s the age-old “nature vs. nurture” debate.

Another way to look at it is as if your future child is a house you want to build. The donor will provide you with bricks for the construction, but the final outcome of the house will depend on various factors, such as the environment provided by the mother's uterus. The number of bricks, their arrangement, and the overall shape of the walls will be influenced by these factors.:  

Do babies from egg donation share genes with the birth mother?

Even if you're using donor eggs for IVF treatment, your baby may still have some of your traits. This is because factors like your stress levels, diet, and behaviour can affect how your baby's genes are expressed. So, your child may have more of you than you think! This can be really reassuring news for those using donor eggs.

It’s true that when someone uses a donor egg, the baby's genes come from the donor and can’t be changed. But the person who carries the baby also plays a part in how those genes are used (or “expressed”). This is called the "epigenetic effect.”

So even when eggs come from a donor, the embryo can still communicate with the mother on a genetic level. This mechanism of “instruction to the embryo genetic material” happens thanks to molecules produced in the uterine fluid. Through this process, the mother can control which parts of the genetic material will be used, how and when, and which ones won't. 

Conclusion

Pregnancy can be an incredible journey, and that's no different for those who conceive through egg donation. Even if you use donor eggs or donor embryos, you play a vital role in your baby's development. 

It's incredible how strong the physical and emotional connection between a mother and her baby can be. That bond only grows stronger through birth, breastfeeding and caregiving, and every stage of the child's growth into adulthood. More importantly, DNA isn’t the be-all and end-all of a family.

We understand that egg donation can raise some concerns. Please don't hesitate to reach out to your Apricity advisor if you have any questions. We're here to provide you with the best possible support. 

References

1. (n.d.). Using donated eggs, sperm or embryos in treatment. Human Fertilisation & Embryology Authority. https://www.hfea.gov.uk/treatments/explore-all-treatments/using-donated-eggs-sperm-or-embryos-in-treatment/

2. Mani, S., Ghosh, J., Coutifaris, C., Sapienza, C., & Mainigi, M. (2020). Epigenetic changes and assisted reproductive technologies. Epigenetics, 15(1-2), 12-25. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6961665/ 

3. Zuccarello, D., Sorrentino, U., Brasson, V., Marin, L., Piccolo, C., Capalbo, A., ... & Cassina, M. (2022). Epigenetics of pregnancy: Looking beyond the DNA code. Journal of Assisted Reproduction and Genetics, 39(4), 801-816. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9050975/