Can freezing IVF embryos reduce pregnancy complications?

Dr Lucy Higgins, Professor Daniel Brison, Dr Mark Dilworth, Professor Ed Johnstone

Babies conceived by IVF have a higher risk of complications and stillbirth. Our scientists are studying why freezing an IVF embryo before it is transferred into the mother’s womb could help to reduce these risks.

Start: April 2020

End: April 2022

Why do we need this research?

Couples who can’t get pregnant naturally can opt for in vitro fertilisation (IVF), where the egg is fertilised by sperm outside the body. However, we know that IVF pregnancies have a higher chance of complications, including stillbirth and death shortly after birth.

We need to understand why this is the case, and what can be done to reduce the risks for babies conceived by IVF.

What’s happening in this project?

After IVF, embryos can either be transferred ‘fresh’ into the mother’s womb, or frozen first and transferred later. Researchers have noticed that babies from frozen IVF embryos tend to grow faster during pregnancy compared to babies from fresh IVF embryos. However, it is not clear why.

A lot of pregnancy complications are caused by problems with the placenta. This has led our researchers to believe there might be differences in the placentas of babies born from ‘fresh’ IVF embryos versus those from frozen embryos. Our scientists will test this theory in this project.

The team will study the placentas of babies born following IVF treatment – some after fresh embryo transfer and others after the embryos are frozen. They will be looking at the weight and size of the placenta, as well as studying the cells and blood vessels inside it. The team will also be asking the mothers for blood samples throughout pregnancy, to look for hormones in the blood which are related to how blood vessels and the placenta develop.

What difference will this project make?

This project will help us to understand why IVF pregnancies have a higher risk of complications. Freezing IVF embryos could become a standard part of IVF treatment and help to prevent pregnancy complications, stillbirth and miscarriage.

Get our research updates

Tommy's funds research across the UK investigating the reasons for pregnancy complications and loss.

If you're interested in being kept updated about our research and news from Tommy's, click here.

More research projects

Make a donation to Tommy's

Read Tommy's new and views

  • Picture of Jennie Agg


    A personal meaning of motherhood and Mother's Day

    We asked our lovely friend and supporter, Jennie Agg, what motherhood and Mother's Day means to her. In this piece, she speaks of her difficult past experiences of Mother's Day, how she has grappled with a sense of being in limbo, and the ultimate purity of her feeling of mother love.

  • Collage of photos showing six women who have experienced baby loss, miscarriage and infertility


    Advice to help you cope on Mother’s Day

    In the lead up to Mother's Day, you might find yourself thinking about how to process your emotions and what to do on the day itself. The anticipation can often feel scary or daunting, and finding ways to look after yourself is important. In this blog, you'll find advice from a few of our lovely supporters who understand how you're feeling.

  • Mother holding newborn baby


    Giving some pregnant women progesterone could prevent 8,450 miscarriages a year, say experts

    New research has revealed the benefits of giving progesterone to women with early pregnancy bleeding and a history of miscarriage.

  • Tim Draycott, Clinical Director of Tommy’s National Centre for Maternity Improvement, giving a presentation to audience at the 'Portraying Pregnancy' event


    Tommy's hosts breakfast morning at the Foundling Museum

    Tommy’s spent yesterday morning at the charming Foundling Museum in London, celebrating the work of Tommy’s National Centre for Maternity Improvement alongside the opening of the museum’s new exhibition, ‘Portraying Pregnancy’.