We’ve been through phases with regard to what is best for patients in terms of stimulation. With the help of David Gibbon who is a senior biologist and a very good friend of mine based in the UK, we’ve been looking into the entire data for many years before we came to the following conclusion. Effectively, there are three ways of doing an egg donation. One is to use frozen eggs. You freeze the eggs from the donor and then, when the time is right, you thaw the eggs, fertilize them with the partner’s fresh or frozen sperm or donor sperm. Then you do a fresh embryo transfer.
The second way is to synchronize the egg donor with the recipient. We stimulate the donor and, at the same time, we prepare the recipient’s endometrium. Then synchronize the egg collection with the maturation and with the timing of the implantation of the embryo so you have fresh embryo created by fresh eggs implanted.
The third way is to use non synchronized cycles. The third option works best in our hands and in my experience in most clinics. Why? Because frozen eggs don’t seem to be behaving as well as we would have liked them to behave. Sometimes they can be a little bit unpredictable and also freezing embryos created by frozen, thawed fresh eggs aren’t always as predictable as we would have liked. Trying to synchronize the donor and recipient is not a brilliant idea, in my opinion. Firstly, because it doesn’t always work. Even the top quality egg donor still has a chance of 5-10% of self-cancellation which is pretty big, in my opinion. The chance of cancelling by the recipient is also 5-10% so if we add those chances then we’re faced with a chance of perhaps 10-15% of not getting the synchronization right. There are also logistics issues when we try to synchronize. We have a couple, we have their characteristics, we were looking for a donor and we find this perfect match, in our opinion. This perfect match is available now, at the time when the recipient is not available to travel. You have to remember that donors are human beings with their own lives, schedules, work, exams, the family sometimes. If they wish to donate, they may be available this month but they may not be available next month. They may not be available at all when the recipient is available and so forth. But even if they are available, even if they are willing, there’s a lot of stress involved trying to synchronize the donor and the recipient. When we audited our results, we found that although the success was 10% less in the synchronized cycles, the experience was terrible compared to the experience of using unsynchronized cycles.
Effectively, that’s what we use now. How do we work? We have the recipient couple or a single lady coming in. We do all the tests and we do all the preparation, the counseling, and so forth. In the case of a couple, the man’s sperm is kept frozen in our unit and then the couple can fly back home. Now we have some time. That’s why we keep a very short waiting list because by the time we’ll have the sperm here, once the suitable donor is available and the compliance is sorted, we proceed with creating embryos. Once we have the embryos in place, those embryos belong to the couple and the donor is effectively, physically, out of the equation. It’s much more applicable to proceed with the frozen embryo. In our experience, not only does that create the maximum possible chance of success which is in the region of 55% if we implant one embryo and 75% success rate if we implant two embryos. We discourage the latter but many couples do opt for a double embryo transfer which we have to offer. It’s legal and although it’s not our first choice, it’s not something we discourage, sometimes we do perform that.
The cryo time of embryos in our experience has never affected the quality. I wouldn’t worry too much about that because the conditions of preserving the embryos are perfect.