Nearly half a century after the birth of Louise Brown, the world’s first ‘test-tube baby’, in vitro fertilisation (IVF) has evolved from a groundbreaking leap of faith in 1978 to a highly refined, well-established clinical process.

Progress included the development of the fast-freezing technique in the mid-80s, which enabled embryos to be frozen for future use, saving couples from having to undergo the egg collection and fertilisation process multiple times.

Other techniques have been introduced, such as Intracytoplasmic sperm injection (ICSI), whereby a single sperm is injected directly into the egg, significantly improving the treatment of male factor infertility.

IVF success rates have grown from 10% in the early 80s to nearly 50% for women under 35 today. This is not the result of a single breakthrough, but rather a series of small, incremental refinements in lab technology, clinical protocols and embryo selection.

Genus’ Embryology director, Karen Thompson, explains how recent advances in embryology, such as genetic screening and AI, are impacting reproductive medicine and patient outcomes.

Advances in embryology

If you look at reproductive medicine over the last decade, the areas where I think we have witnessed the most change are time-lapse imaging, AI, and pre-implantation genetic testing.

Time-lapse imaging itself is not AI. It is imaging technology we use to continuously monitor embryo development. However, it produces vast amounts of data, which is being increasingly analysed by AI algorithms to improve embryo selection.

Time-lapse imaging gives us so much information, and watching an embryo grow on video is still amazing, regardless of how many times you watch it.

In addition to helping with embryo scoring and grading, AI has the potential to assist with sperm and egg selection, and it will continue to develop to other clinical aspects of treatment.

The impact of pre-implantation genetic testing on fertility medicine

Pre-implantation genetic testing has exploded in recent years. The technology behind PGT-A is continually evolving, and the accuracy of testing has improved significantly over recent years. However, it’s important to understand that, like any medical test, it does have limitations.

When we perform PGT-A, we biopsy a small number of cells, typically between 5 and 10, from a blastocyst containing around 100 to 150 cells. While this provides valuable information about the embryo’s chromosomal status, it may not always be fully representative of the entire embryo. For this reason, PGT-A should be viewed as a screening tool that helps prioritise embryos rather than a guarantee of success.

As an embryologist, I always encourage patients to consider PGT-A in the context of their own circumstances. For younger patients undergoing their first IVF cycle, PGT-A may not be necessary. Younger women are more likely to produce chromosomally normal embryos, and we can often identify the embryos with the highest potential using non-invasive techniques such as time-lapse imaging and AI-assisted embryo assessment.

The conversation may be different for older patients, where the likelihood of chromosomal abnormalities increases with age. In these cases, PGT-A can help identify the embryos most likely to result in a successful pregnancy, potentially reducing the time taken to achieve that goal.

It can also be an important consideration for patients who have experienced recurrent miscarriage. While PGT-A cannot eliminate the risk of miscarriage entirely, it may help reduce the likelihood of transferring embryos that are chromosomally abnormal and therefore less likely to develop into a healthy pregnancy.

Ultimately, PGT-A is an exciting advance in reproductive medicine, but it isn’t the right choice for everyone. The key is understanding both the benefits and the limitations so that you can make an informed decision about what is best for you and your fertility journey.

Automating the IVF process

Automation is also an area of increasing development, designed to eliminate the risk of human error. Robotic Intracytoplasmic Sperm Injection (ICSI) is an emerging technology in the US and has been successful in pilot studies.

The vitrification (freezing) process will also move towards greater automation. Egg freezing is increasing in popularity, whether that’s for fertility preservation by choice or because they are about to undergo fertility-destroying treatment.

As highly skilled and experienced embryologists, we handle thousands of gametes or embryos every year; however, validated automation could be used to ensure the process is consistent and less prone to error or variation, which will ultimately benefit our patients. For them, this may be their chance to have a child.

Both of these are emerging technologies and are not yet in routine clinical practice, but they are signs of things to come.

Overall, the fundamentals of IVF haven’t changed since the birth of Louise Brown; it’s a series of marginal gains that improve your chances of a successful outcome.

About the author:

This post has been written or personally reviewed by Karen Thompson, BSc Hons, PGDip in Clinical Embryology, Embryology Director and HFEA Person Responsible at Genus Fertility.

Karen is a Senior Clinical Embryologist with nearly 30 years of experience in assisted reproduction and fertility laboratory leadership. She is the Embryology Director and HFEA Person Responsible at Genus Medical Fertility, where she leads the development and governance of the embryology laboratory and clinical science services.

Read Karen’s full biography →