Freezing embryos for later FETs because of the current COVID-19 outbreak may not make sense for everyone. Image by Irina Murza via Unsplash.
[This article deals with a rapidly developing situation. It was written by Norbert Gleicher, MD, on April 16, 2020 and published on April 17, 2020. For a list of all COVID-19 Bulletins, scroll to the bottom.]
Something “ funny” has been going on in some IVF center over the last fewe weeks. Quite a number of patients reported that they were advised to freeze their eggs and/or embryos rather than to complete their IVF cycles with fresh embryo transfers. The rationale? The effects of the COVID-19 virus on pregnancy were not well understood yet and, therefore, it made more sense to delay pregnancy via egg- or embryo-banking than trying to conceive right now.
CHR does not share this opinion. Here is why: Though we agree, and have stated repeatedly in these Bulletins and in the VOICE, CHR’ monthly newsletter, that the complete impact of the COVID-19 virus on pregnancy is not yet fully known, most published data have been rather reassuring and have not demonstrated any of the risks associated, for example, with the influenza virus. It, indeed, appears that the COVID-19 virus does not (or only extremely rarely) cross the placental barrier between mother and offspring.
This, of course, does not mean that a COVID-19 infection in pregnancy may not cause medical problems. Just fever can cause problems, for example; but, in general, reports have been reassuring. Moreover, not a single professional advisory body, in contrast to the Zika virus outbreak during 2015-2016, for example, has suggested that couples should avoid pregnancy in general. Why would infertility patients avoid pregnancy, if the general population is not advised to do the same? One, indeed, could argue the opposite, namely that infertility patients may have a rationale to try, even when the general population is advised against doing so, since some infertile women have no time left to delay conception.
Another reason CHR opposes the all-freeze concept lies in the fact that every time we freeze either eggs or embryos, we give away a little bit of pregnancy chance without any compensatory benefit. CHR does not subscribe to the hypothesis suggested by some colleagues that egg and embryo freezing as well as egg and embryo banking improves IVF outcomes. We consider this only one of many “hypotheses” that have been propagated in recent years in IVF practice without any proper statistical support. That fresh is better than frozen may, indeed, be a universal concept in IVF. The only time CHR recommends cryopreservation is when we have more eggs/embryos than we are able to use fresh. In short, if you have a reason to undergo ovarian stimulation and egg retrieval during the COVID-19 epidemic, you, likely, also have good reasons to have a fresh embryo transfer now and to conceive right now, rather than freeze the embryos for frozen embryo transfer (FET) later.
It is also important to consider that most virologists now believe that COVID-19 may be with us for some time to come. Indeed, many expect expect it to become a seasonal virus, not dissimilar to the influenza (flu) virus. If that were to be the case, then a woman could conceive in a quiet COVID-19 period and end up delivering in the midst of yet another major outbreak (or vice versa). We simply don’t know, and CHR wouldn't want to offer medical advice based on rumors and guesses.
Interestingly, colleagues from Columbia University hrere in NYC just published a research letter in The New England Journal of Medicine after testing for the virus in 215 women in labor. A full 15.4% were culture-positive while in labor, but only 1.9% were clinically symptomatic (Sutton et al., N Engl J Med 2020). That says something about existing prevalence of the COVID-19 virus in our population, at least in NYC. It, likely, also means that herd immunity in the population against the virus must be already much better than generally assumed by many experts. How good it is, we, however, will only get to know once we have reliable antibody tests available that can tell us who does and does not have immunity to the virus.
Norbert Gleicher, MD, leads CHR’s clinical and research efforts as Medical Director and Chief Scientist. A world-renowned specialist in reproductive endocrinology, Dr. Gleicher has published hundreds of peer-reviewed papers and lectured globally while keeping an active clinical career focused on ovarian aging, immunological issues and other difficult cases of infertility.
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