IN BRIEF - 4TH MAY 2017
Dr Christian Ottolini, senior embryologist and lab manager for pre-implantation genetics at London Women’s Clinic, on innovations in addressing infertility
What brought you to work in IVF innovation at London Women’s Clinic?
From the very early stages of my career, I have always understood this as more of a vocation than a job. My subject areas are embryology and pre-implantation genetics.
What is the difference between the two?
Embryology in its simplest terms is obtaining eggs, mixing them with sperm to create embryos, growing those embryos in a lab and then transferring them to the uterus, with all the procedures that might happen in between, like freezing. The pre-implantation genetic screening side of things is a newer discipline, which has really come to the fore in the past 15 or so years. Though the very first successful genetic analysis on embryos was done in the early nineties, it only really took off with the recent development of newer and more effective technologies. If you worked in embryology you worked on the embryos, and if you worked on pre-implantation genetics you worked on the genetic analysis of the embryos. What myself and my team have tried to do is demonstrate that the two go hand-in-hand. You can’t really improve one without the other because they are intrinsically linked.
In what way are they linked?
The main reason for IVF to fail is a genetic issue linked to increased maternal age. Once a woman passes the age of 35, the majority of embryos produced from her eggs are chromosomally abnormal, and a chromosomally abnormal embryo will not result in a normal pregnancy. There is the extreme of Down’s syndrome, which is an extra copy of chromosome 21, as well as other configurations of chromosomes which can cause potentially life-threatening disabilities, or miscarriages – something sadly prevalent among IVF patients. To have that overwhelming joy of discovering you are pregnant only to lose the baby several weeks later is a devastating circumstance which, through the One by One IVF programme we have set up at the London Women’s Clinic and our partner clinic the Bridge Centre, we are trying to avoid.
Most clinics seek to overcome the problem of chromosomally abnormal embryos by transferring more embryos. However, that is when the whole issue of multiple pregnancies comes to the fore. The Human Fertilisation and Embryology Authority, alongside clinics in the UK, is now aiming for one healthy baby per pregnancy—and for us that means changing the standard approach. There is good evidence that you cannot simultaneously optimise egg collection and optimise the uterus environment into which you transfer the embryos: the two are sort of conflicting. What we have done is disjoin the cycles so that we do the egg collection, create the embryos and then freeze them. Then, in the subsequent ovarian cycle, we can optimise the environment into which the embryo goes before we do the transfer. This is nothing new, but what we’re doing is putting it at the centre of our programme. For us, disjoining the cycles, not putting them together, is the standard. And the thing that underpins it is a robust freezing protocol and improvements to freezing techniques. We can now freeze all of the embryos and then transfer them one by one in separate embryo transfer cycles.
Where does the genetic testing come in?
As I mentioned, it is highly likely that the majority of embryos we transfer in IVF for patients over the age of 35 are chromosomally abnormal. With genetic testing, we have a way of telling if they are. It is not 100% accurate, but the robustness of the tests we’re using is increasing on pretty much a daily basis. We scrutinise all our results—and through that scrutiny, we endeavour to never discard an embryo that could result in a pregnancy. We can achieve very high pregnancy rates per single embryo transferred, which has been particularly successful for our older patients, and significantly reduce the chances of miscarriage. As it stands, a quarter of all patients that travel through IVF miscarry; within our clinic, after chromosomal screening of the embryos, that plummets right down to around 10%, even in high risk patient groups.
What about egg and sperm donation?
For women over a certain age, unfortunately they will not produce any chromosomally normal embryos, so their best option would be to use donor eggs. All donor eggs in the UK come from women under 35 so a lot less likely to have any genetic issues. They are all also well-screened before being accepted onto the programme. Our sperm bank, the London Sperm Bank, is one of the biggest in the country and, being based in London, we recruit a breadth of multicultural sperm donors, which is good for patients looking for a particular phenotype.
How is male factor infertility addressed?
Male infertility is not too much of a problem these days. One of the non-incremental improvements in IVF treatment was the introduction of intra-cytoplasmic sperm injection (ICSI), which was disseminated about the world in the early 1990s. ICSI enables us to create an embryo with a single sperm. It’s very unlikely that a man will have no sperm at all in his semen, but even if he does, it is now possible to perform surgical sperm retrievals. We have a world expert, Dr Richard Balet, working at the London Women’s Clinic who specialises in this.
How can women optimise their chances of success?
As well as having a healthy lifestyle, one of the services we provide at the London Women’s Clinic is egg freezing. If a woman freezes her eggs when she is, say, 28 years old, then those eggs will remain 28 even when she’s 40. Our freezing techniques make us confident that those eggs will behave normally when thawed, even after they have been frozen for several years. It’s not a guarantee, but more of an insurance policy. All too often, we see 42-year-old women come in, saying they have been trying for children for the last two years but have struggled to fall pregnant – and we have to tell them unfortunately there’s a problem. Sadly, I think fertility has been rather left by the wayside when it comes to education in schools, universities and GP surgeries. Women should be aware of the impact of age on their fertility and what options they have for the future. I would hope to see that improve.