How Many Embryos Should We Use in IVF?

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Hugo Verhoeven, MD: “Good morning, my name is Hugo Verhoeven from the Centre for Reproductive Medicine in Dsseldorf, Germany. I’m on the editorial board of OBGYN.net and I’m reporting from the fourth COGI meeting, Controversies in Obstetrics and Gynaecology, in Berlin, Germany. It is an exceptional honour for me to talk this morning with Dr. Barri from Barcelona in Spain, who is well known in the world of in vitro fertilisation worldwide. The topic we are going to discuss today is still a hot topic in our world of infertility treatment: how many embryos are we giving back? What are the criteria for selection?

Not so many years ago, the policy was to give back up to three embryos. Patients older than 35 or 38 got four, five, six embryos. This was also very different between old Europe and the United States, Australia, Israel, where they had no problems giving back more embryos, four, five, six, even in younger patients. What changed?”

Pedro Barri, MD: “I think that there is a social trend related to the increased incidences of multiple pregnancies all over the world. I think that there has been a measure of change in the IVF world related probably to the conditions in the IVF lab. It appears that most IVF programs reach implantation rates greater than 25% perhaps. 

This means that we don’t need anymore to replace, in normal IVF patients, probably more than two embryos, and my topic will be to present some data in order to find out the criteria to select which patients could have the same pregnancy rate receiving one or maximum two embryos without compromising their final result – their final expectancy of getting pregnant. 

I think this is a movement that has started in Europe, in the Scandinavian countries, and I think that we all have to move in this direction. Probably embryo replacement with four embryos should be completely abandoned, should disappear. We have to fight to increase the selective single embryo replacement trying to avoid the incidence of triplet pregnancy, and trying to reduce as much as possible the incidence of twin pregnancy.”

Hugo Verhoeven, MD: “What many people still think is that the more embryos you give back, the higher the overall pregnancy rate is, so that is the argument to say: if we give more embryos, we have more of our patients that will be pregnant. This is not true. Could you comment on that?”

Pedro Barri, MD: “This is not true in my opinion, anymore. In the case of normal patients with a good cohort of normal embryos in which we can select one, or a maximum of two embryos, to be replaced, and we can freeze the rest of the cohort of the embryos, we can have the advantage of a good freezing progress that will give us a final cumulative pregnancy rate, counting the first embryo replacement plus at least one cryo replacement and reaching 60%, 70% of cumulative pregnancy rate with a low multiple pregnancy rate, and I think that the goal is to reduce the multiple pregnancy rate without reducing the total pregnancy rate.”

Hugo Verhoeven, MD: “That’s the point. So maybe we should talk about blastocysts. You can give back two or three embryos on day 2 or 3 or give back two or three blastocysts on day 5? Blastocysts have a very high implantation rate, so giving back three blastocysts will induce a lot of high order multiple pregnancies. Correct?”

Pedro Barri, MD: “I think that in order for this policy of reducing the number of embryos to be replaced, you can work exactly in the same direction either by replacing on day two, day three, one or two selected embryos or by replacing on day five, six, a single blastocyst. 

But, it’s important to identify those patients, who will be or who are at higher risk of multiple pregnancy, and we have observed retrospectively, by analysing our own data, that the true parameters which were involved in the study of multiple pregnancy were the age of the patient and the number of top quality embryos. 

We have developed a scoring system, that I am going to present here, in which, according to the value of this score, there is a suggestion to replace one embryo, two embryos, or three embryos. We explain this score to each couple or to each patient and we let them know which are our suggestions for them, whether to give them back two embryos or a single one or three. But the final decision that depends on the couple’s decision and if they are well informed, they make their own decision.”

Hugo Verhoeven, MD: “Is there a law in your country, Spain, regulating how many embryos you are allowed to give back or is it the decision of the patient and the doctor?”

Pedro Barri, MD: “There is a law since 1980, but the law does not regulate this specific point, so this is a clinical decision taken by doctors and the patients. So there is no legal limit on the number of embryos to be replaced.”

Hugo Verhoeven, MD: “So, in conclusion, thanks to better techniques, we can culture much better embryos, the implantation rate for embryos will be higher so there is no reason anymore to give back a lot of embryos in order to compensate the low implantation rate per embryo … “

We know that in the Scandinavian countries the policy is to give back one embryo, the exception would be the patient who is older, who is 35, 36, 37, where they are going to give back maybe more embryos. Even in those patients, we are, in Germany, not allowed to give back more than three embryos. Is this correct?”

Pedro Barri, MD: “I fully agree. I think the final message is exactly this one, that we have to select patients with good quality embryos and in these patients their pregnancy rates will not be effected by reducing from three to two or from two to one the number of embryos which we selectively replace. 

In cases of patients over 38 or over 40 years of age, I think that their prognosis is poor and, of course, you can replace three or maybe four embryos, but their chances of getting pregnant are low and their chances of receiving a multiple pregnancy are also low. I think that the good condition is for the general population is exactly the same, the same that you have mentioned before.”

Hugo Verhoeven, MD: “And to conclude in a provocative way, centres who are advising their patients to have a transfer of more then three embryos, is this a proof of bad laboratory quality?” 

Pedro Barri, MD: “I don’t want to say bad, but I think the standard IVF program with standard cleavage and fertilization rates should recommend this policy of reducing the percentage of embryo replacement with three embryos replaced and move to a high percentage of double embryo transfers or single embryo transfers.”

Hugo Verhoeven, MD: “Dr. Barri, this was very, very informative for all of us. Thank you very much. Muchas gracias.”

Pedro Barri, MD: “You’re welcome. Denada.”