A New York Times article exploring the rapidly evolving (and aggressively marketed) world of embryo screening technologies for in vitro fertilization (IVF) quoted Dr. Gleicher.
The article, published in NYTimes on July 11, 2014, examines several tools and techniques, including preimplantation genetic screening (PGS), developed with one main purpose: to identify the healthiest embryos for transfer in IVF cycles. The premise of the tools and techniques is that by selecting the “healthiest and strongest” embryo from those available after an IVF cycle, IVF centers can improve pregnancy rates for their patients, and potentially reduce the number of embryos necessary to be transferred to offer a decent chance of pregnancy.
It is known that as many as 50% of embryos produced in IVF cycles, even in young couples, are aneuploid (chromosomally abnormal). Chromosomally abnormal embryos usually fail to implant when transferred into the uterus, and even those do manage to attach to the uterus are usually miscarried in the early stage of pregnancy. By eliminating chromosomally abnormal embryos from the candidates for transfer, theoretically, IVF centers should be able to improve pregnancy chances because the embryos that are selected after screening and transferred into the uterus should have a better chance of implantation and subsequent development.
However, as our recent OPINIONs commentary piece (among numerous other CHR publications both here and in medical journals) pointed out, this approach is unlikely to benefit older women and young women with premature ovarian aging (POA). These women, who have diminished ovarian reserve tend to produce a very small number of eggs and embryos in each IVF cycle. When there are only one or two embryos to “choose from,” screening for chromosomal abnormalities does not offer much added value to these patients for a couple of reasons. For one, their embryos may not survive to the 5th day of culture (which tends to be the PGS day of choice in order to allow for a biopsy of more than one cell), while they may continue to develop in the more natural environment of the uterus. Even if the embryos do survive to day-5, biopsies can damage otherwise viable embryos. Unproven accuracy of the technique is yet another concern.
In the article, Dr. Gleicher laid out all these concerns in opposition to the growing use of embryo screening techniques, especially PGS. In an illustration of Dr. Gleicher’s point, the article refers to a CHR patient (who has been featured in the December 2012 issue of CHR UPDATE) who was able to get pregnant and give birth after a non-PGS cycle at CHR, while her previous attempts involving PGS at another center left her empty-handed.