- Products & Services
- Knowledge Base
NEW YORK, NY, April 20, 2016 /24-7PressRelease/ -- Kira Peikoff offers today in the Science Time section of The New York Times a first overdue media glimpse into a rapidly evolving controversy in the in vitro fertilization (IVF) community surrounding a procedure called preimplantation genetic screening (PGS).
PGS was first proposed over 10 years ago, and is based on the hypothesis that, since many human embryos are chromosomally abnormal (aneuploid), elimination of aneuploid embryos prior to transfer into the uterus would improve clinical pregnancy and live birth rates and reduce miscarriage rates. Even well thought out hypotheses often, however, do not pan out clinically, which is what happened to PGS when first introduced (PGS.1.0), resulting in formal declarations by most professional bodies that the procedure was ineffective and should not be used.
With the development of better genetic diagnostic techniques, a second generation PGS evolved (PGS.2.0), and rapidly gained popularity. In 2015, approximately 20% of all IVF cycle in the U.S. are believed to have made use of PGS at an additional average cycle cost of ca. $3,000-4,000. Importantly, this happened without even a single properly conducted study to confirm improved IVF outcomes from PGS 2.0 in nonselected patient populations. A number of studies that attempted to demonstrate such benefits, indeed, failed to do so.
Disturbed about these developments, and especially after seeing increasing numbers of patients who in repeated IVF cycles with PGS never reached embryo transfer because all of their embryos were reported as aneuploid, New York's Center for Human Reproduction (CHR) in 2014 decided to offer such patients, with very detailed informed consent, the option of transferring selected allegedly aneuploid embryos. This practice was initiated under the assumption that PGS 2.0 was unreliable in determining whether an embryo was aneuploid or chromosomally normal because the embryo biopsy was performed from the trophectoderm of the embryo, where mosaic embryos (embryos harboring both normal and chromosomally abnormal cell lines) often segregate abnormal cell lines to the placenta and NOT to the cells from which the embryo will be derived. Trophectoderm (and the derivative placenta), is well known to be mosaic, assuring a high potential for false-positive results (i.e., normal embryos described as aneuploid) since the areas of biopsied trophectoderm would NOT reflect the inner cell mass from which the embryo arises.
After establishing two chromosomally normal pregnancies from transfers of embryos diagnosed as aneuploid, CHR was joined by two other New York City based fertility centers Fertility Specialist in New York (Andrea Vidali, MD) and Braverman IVF & Reproductive Immunology (Jeffrey Braverman, MD) in forming the International PGS Consortium in an attempt to further investigate the efficacy of PGS 2.0.
As Peikoff notes, an initial report of 3 normal births following 5 transfer attempts of alleged "aneuploid" embryos in October 2015 at the annual meeting of the American Society for Reproductive Medicine attracted considerable attention, and was followed by reports of 2 more healthy pregnancies for a total of 5 out of 8 attempted transfers by Consortium members.
What Peikoff, however, failed to report in her piece was that, unknown to Consortium members, a group of Italian investigators during the same time period were also transferring "abnormal" embryos in cycles were no normal embryos were obtained during PGS. These investigators in November of 2015 reported in The New England Journal of Medicine 6 healthy births in 18 attempts of transfer. Combined, both groups, thus reported 11 chromosomally normal pregnancies after 26 transfer attempts for an astonishing 42.3% live birth rate and without even a single clinical miscarriage. Also unreported by The New York Times, an Israeli group reported in February of this year in the medical journal Gynecologic Endocrinology that concordance between trophectoderm and inner cell mass biopsies in human embryos was very poor, buttressing concerns over the reliability of PGS results.
In addition to presenting the view point of CHR and the Consortium members by quoting CHR's Medical Director and Chief Scientist, Norbert Gleicher, MD, likely in an attempt to offer a balanced presentation, the piece in The New York Times gives even more exposure to a number of experts who, still, are strong advocates of PGS 2.0.
Because CHR and the members of the International PGS Consortium do not agree that current outcome data still support routine utilization of PGS 2.0 in attempts to improve IVF outcomes, and especially not in poor prognosis patients with small embryo numbers, we feel obliged to issue a warning to the public about the indiscriminate use of PGS in association with IVF. Moreover, we also wish to warn patients that by discarding embryos diagnosed by PGS to be aneuploid, potentially normal pregnancy and delivery chances will be materially compromised.
The International PGS Consortium is also aware of additional studies, currently still unpublished, which offer further evidence for the inability of PGS 2.0 to reliably define embryos by single trophectoderm biopsy as either euploid (chromosomally normal) or aneuploid. Moreover, the Consortium is also aware of pending publications of studies which demonstrate that the utilization of PGS 2.0 actually reduces pregnancy and live birth chances in association with IVF.
As members of the Consortium, Drs. Gleicher (on behalf of CHR), Vidali and Braverman are available for further comments by contacting Ms. Yu Kizawa. Dr. Vidali (and his wife), personally, experienced an IVF cycle in which all embryos were declared aneuploid, only to learn upon repeat analysis that 40% were found to be chromosomally normal (euploid).
The Center for Human Reproduction (CHR) is an internationally recognized clinical and research center in New York City specializing in female and male infertility, which has contributed hundreds of peer reviewed publications to the medical literature.
# # #