Improving Pregnancy Chances with New Rescue IVM (In-Vitro Maturation) Process
Dr. Gleicher explains CHR’s practice of retrieving eggs early to avoid “overcooking” and their success with a new Rescue In-Vitro Maturation method.Want to Consult Dr. Gleicher?
I want today to talk about the procedure that CHR first introduced approximately three years ago on an experimental basis, which in the meanwhile, at least that our Center, has become quite routine in our IVF practice. It is a procedure which is particularly important for women who produce very small numbers of eggs and embryos where really every egg and every embryo that we can obtain counts.
What we mean by “Rescue IVM” is that whenever you go through an IVF cycle, you usually end up with a spread in the maturity levels of the eggs that are being obtained upon egg retrieval. Most are hopefully perfectly mature, but some will be immature and some may actually be over-mature (we call arthretic).
The purpose is to have a large majority among the mature eggs and that’s what is usually achieved if IVF cycles are managed well, but as women get older, something very interesting is happening and this was actually for the first time quite dramatically documented by us here at CHR probably because we treat so many older and sometimes really quite old patients. What we know is that as women get older, the spread widens and in very old patients (and by that I mean women 45 or older who are still trying to get pregnant with use of their own eggs), the spread gets so wide that we frequently end up getting two separate generations of follicles. We are getting very immature and over-mature eggs if we follow standard practice patterns.
And once this was recognized, we had to find a solution. We could either give up on the generation that was over-mature or we could try to go earlier (meaning remove those eggs at an earlier stage, which usually means smaller follicle sizes), but that would move the immature generation even more towards immaturity. So this was a difficult decision and what we decided to do is the second choice. We said, “Let’s try to prevent eggs from quote-unquote overcooking– even if it means we get we want immature eggs– but then let’s take those immature eggs and try to mature them in the laboratory.”
Now we have been doing that for quite a number of years and have published on it, but the way we have been doing this is by Handling the eggs in a routine fashion, which means that after the the eggs are retrieved, we strip them of what is called the cumulus cells (those are the cells that are feeding the eggs), and instead of fertilizing immature eggs right away, we cultured them in our laboratory overnight and only try the next morning to fertilize.
That was the initial Rescue IVM that we and some other centers have been practicing for a number of years. But when we do that we get maturation only in eggs that are mildly immature in the first place, but now that we were in these much older patients moving towards early and earlier retrieval and thereby move the immature is even more immature, those eggs wouldn’t mature in this fashion and so we decided a few months ago to change how we cultured those eggs overnight. And we stopped stripping them of their cumulus cells and we started culturing them overnight with the cumulus cells still attached.
This has one difficulty and that difficulty is that when the cumulus cells are still attached it is very hard under the microscope (it’s actually impossible) to determine exactly what the maturity level of the egg is. But since we had moved so early and we knew–usually from a previous cycle– at what point the eggs mature into the different stages, we could by going even earlier be pretty sure that all of those eggs were very immature and so we didn’t even have to visually confirm that they were immature before we made that decision to culture overnight. And therefore we could afford not to remove the cells, and we have done this now for over half a year and I’m very pleased to report that we have done this with really wonderful results.
We are in the process of preparing our first publication on the subject, but it really has made a significant difference and so this new form of Rescue In-Vitro Maturation (Rescue IVM) has now become a routine practice here at CHR and is just another small step in our efforts to get better and better results in older and older patients. Thank you.