Female & Male Infertility News
Female Fertility
Why is extended embryo culture to blastocyst stage widely considered the standard of care?
In an interesting Inklings article in Fertility and Sterility (yes, sometimes even Inklings articles in F&S can be interesting!), two well respected authorities in REI Raoul Orvieto, MD, MMSc from Tel Aviv University in Israel and co-editor-in chief of Reproductive Endocrinology and Biology, and Kurt T. Barnhart, MD, MSCE, from the University of Pennsylvania and editor-in-chief of F&S, asked exactly this question.
They have good reason because a very large majority of IVF clinics worldwide are, by now, routinely and automatically culturing embryos in every IVF cycle to blastocyst-stage. Moreover, ASRM, since 2018 practically considered blastocyst-stage culture in combination with single embryo transfer to be standard of care2 and, in at least one Practice Committee opinion, peripherally, indeed, referred to blastocyst-stage embryo transfer as standard of care. Between 2014 and 2020 alone, blastocyst-stage culture increased from 65.3% to 85.4% of U.S. IVF cycles,2 and by now, one has to assume—must be even more prevalent.
Yet the CHR never followed this train because, as repeatedly discussed in these pages and the CHR’s publications in the medical literature, the CHR never believed many of the alleged outcome advantages routine blastocyst-stage culture of embryos was supposed to deliver. To the contrary, the CHR for over 20 years has been arguing that routine blastocyst stage culture adversely affected IVF cycle outcomes in several subgroups of infertile women, but especially in women with low functional ovarian reserve and/or older women in general. But once the Colorado group published their first blastocyst paper claiming amazing pregnancy rates, blastocyst stage embryo culture slowly became unstoppable, whatever the arguments against were.
The CHR, therefore, in the past repeatedly described the initial blastocyst papers by Gardner et al in 19984 as the likely most damaging single publications in the development of IVF since its inception and sees this paper as, maybe, the most consequential misdirection of clinical IVF practice since the birth of the Brown baby, the first IVF baby. And—not to be forgotten—extended embryo culture to blastocyst-stage is, of course, also closely linked to the concept of universal single embryo transfer and, of course, preimplantation genetic testing for aneuploidy (PGT-A), two other widely accepted routine practices in IVF, the CHR considers in many clinical situation to represent significant additional misdirections in routine IVF practice.
Seeing other prominent colleagues questioning the current almost universal utilization of blastocyst stage culture in IVF is, therefore, quite rewarding. Within this context, it is important to repeat another point we have been making for years regarding established practice patterns: Practically no practice in medicine is applicable to every patient. Therefore, practice strategies must differ depending on the patient population. It is by following this recognition, the CHR has, in principle, always been correct when not following many worldwide deeply engrained practice patterns, from routine blastocyst-stage transfers to routine elective embryo transfer, to all-freeze cycles, etc. Yet, practically uniformly, the CHR, therefore, has ultimately been conformed to be on the right side in the various practice disputes, even if it at times, as in association with PGT-A, can take decades to be confirmed.
The two authors of the discussed paper in their commentary reached the correct conclusion for almost all IVF practice, namely that cleavage- or blastocyst-stage transfers should be individualized. This is, of course, exactly what the CHR’s policy has been for over 20 years. For further details, we recommend the complete paper. It is only three pages long.
References
Orvieto R, Barnhart KT. Fertil Steril 2025;124(1):37-39
Practice Committee of the ASRM. December 1, 2018; https://www.asrm.org/practice-guidance/practice-committee-documents/blastocyst-culture-and-transfer-in-clinically-assisted-reproduction-a-committee-opinion-20182/?_t_tags=siteid%3a01216f06-3dc9-4ac9-96da-555740dd020c%2clanguage%3aen&_t_hit.id=ASRM_Models_Pages_ContentPage/_ed796f38-49a9-4de6-a6d9-0b6628d77ff2_en&_t_hit.pos=54
Claffey A, Doody K. Fertil Steril 2023;120(1):315-e16 (abstract)
Gardner et al., Fertil Steril 1998;691:84-88
Male Infertility
Semen quality as a predictor of longevity?
This is what a recent paper by a Danish investigator in Human Reproduction of 78,284 men suggested when concluding that men with a total motile sperm count of >120 million could expect to live 2.7 years longer than men with a total motile sperm count of >0 and up to 5 million. Men with a total motile count of >120 million could expect to live 80.3 years, compared to 77.6 years among men with a total motile count of >0 to 5 million. All semen parameters, moreover, were negatively associated with mortality in a dose-response manner both in the total population and the more recent subpopulation (P-trend for all semen parameters <0.001). Adjustment for educational levels and prior diagnoses did not change the estimates in the latter.1
This is a novel finding but makes evolutionary as well as biological sense, and was in the journal accompanied by a very worthwhile to read commentary (without fancy name) by an Australian colleague,2 which went into detail about possible explanations which the paper, by itself, did not do to the same extent. We were especially intrigued by the commentary’s discussion of the differences between female and male in the importance of the immune system, and strongly recommend both papers in combination.
References
Priskorn et al. Hum Reprod. 2015;40(4):730-738.
Aitken RJ. Hum Reprod. 2025;40(4):580-584.
A new way to test semen quality?
At least with bull semen, it works1 and that suggests that it may also work with human semen, a recent short article in Scientific American suggested.2 Calling it “fertility physics,” the latter article is easier to understand than the original one, which describes the test as “connecting droplet adhesion with sperm kinematics.” We, therefore, will use the simpler explanation: To reach the egg in a long journey from vagina through the uterus and against tubal peristalsis through the complete length of the tube to reach the egg situated in the ampulla of the tube (where fertilization occurs), the sperm has to “wiggle” vigorously (in traditional semen analysis described as “motility”).
The new test uses basic physics to measure sperm activity and is promised to be simpler, less work-intensive, and, therefore, cheaper. The ultimate plan is to develop this technique to allow for home semen analyses, which would be a neat screening tool.
References
Shyam et al. Adv Mater Interfaces. 2025;12(9):240680.
Thompson J. Sci Am. June 2025:18.
A sperm donor with a rare genetic mutation that predisposes to cancer—10/67 of his offspring now have cancer
Presented publicly for the first time at the annual conference of the European Society of Human Genetics in Milan, Italy, in May, and reported by CNN Health,1 a European sperm donor—apparently active throughout Europe—fathered at least 67 children. Among those, so far, 10 have been diagnosed with cancer.
Unknown to him and others, he carried a mutation in the TP53 gene. This gene is often also called the p53 gene and is a very important tumor suppressor gene that plays a very important role in suppressing cancer development by controlling cell growth, DNA repair, and apoptosis. Mutations of the gene are found in approximately half of all cancers.
Though the donor’s sperm was used all over Europe, he donated only in one sperm bank, symbolically named the European Sperm Bank, and had been tested beyond genetic minimum requirements for sperm donors, but those do not include testing for mutations in the TP53/p53 gene.
Neither Europe nor the U.S. currently has legal restrictions as to how many children a sperm donor can father. The ASRM, however, recommends a limit of 25. ESHRE has no explicit limit but recommends that sperm banks set an appropriate limit.
The European Sperm Bank, of course, had no such limit, though, through its VP of corporate communications, now announced that this will change.
Reference
1. Guy J. CNN Health. Updated May 27, 2025. https://www.cnn.com/2025/05/27/health/genetic-mutation-sperm-donor-scli-intl