Highlights From the 2015 Meeting of The American Society For Reproductive Medicine - IMPROVING IVF SUCCESS RATES
HIGHLIGHTS FROM THE 2015 MEETING OF THE AMERICAN SOCIETY OF
REPRODUCTIVE MEDICINE - IMPROVING IVF SUCCESS RATES
Many techniques for improving IVF success rates were discussed during this course including
discussion of alternative super-ovulation stimulation protocols, the concept of freezing all
embryos in the stimulated cycle with embryo transfer delayed until the next cycle, better
techniques of embryo transfer, and latest methodology of genetic assessment of the embryo in
an effort to select the best embryo for transfer. The latest technology available for assessing the
genetic makeup of the embryo, "next generation sequencing", allows a more accurate and
detailed analysis of the embryo. This technology allows for fewer false positive and fewer false
negative results.
There was much discussion about how to decrease IVF failure rates, since failure of the embryo
to implant causes so much stress and unhappiness among our patients. It was pointed out that
miscarriages have the greatest negative emotional impact on patients. Clearly the best
available technique to achieve the highest ongoing pregnancy rate and the lowest miscarriage
rate is through selection of the best embryo for transfer, and the best method of finding the
embryo most likely to result in a live birth is pre-implantation genetic screening (PGS). Currently
performing embryo biopsy on the 5th day after insemination followed by analysis of all
chromosomes seems to be the best approach. Although PGS seems to raise the ongoing
pregnancy rates and reduce miscarriage rates significantly, it does usually require that embryos
be frozen to allow time for the chromosomal studies to be done. In addition, at the present time,
most insurance companies are not covering this procedure, even in states where IVF coverage
is mandated by law. The cost for this procedure is in the range of $4000 - $5000 depending on
which lab is chosen and the geographical location. The challenge in the future is to reduce the
costs of PGS so that more patients may screen their embryos. The knowledge that an embryo
is genetically normal allows several distinct advantages including the following:
1) The implantation rate of screened genetically normal embryos (euploid) is very
high. For this reason, single embryo transfer is recommended, drastically reducing the chance
of twins. Because singleton pregnancies are much safer than multi-fetal pregnancies,
transferring a single genetically normal embryo is the ideal approach.
2) The pregnancy rate (implantation rate) for a genetically normal embryo is
significantly higher than for an unscreened embryo.
3) The miscarriage rate is significantly lower when a genetically normal embryo is
transferred compared to a non-screened embryo.
Related to genetic screening of embryos and improvements in embryo cryopreservation, an
alternative approach to managing infertility related to diminished to ovarian reserve is gaining
traction. Some centers are advocating that patients who are poor responders undergo multiple
egg retrievals and allow all embryos to grow to the blastocyst stage. Any embryo that forms a
blastocyst undergoes biopsy and the biopsy material is stored. Once the patient has
accumulated several embryos, each of the biopsies undergoes genetic study (either array CGH,
comprehensive chromosomal screening, or next generation sequencing). If one or more of the
embryos is genetically normal, the patient has a frozen embryo transfer. The advantages of
this approach are that the patient reduces the disappointments and delays associated with
treatment failure and miscarriage. For patients who may be in their late 30's or early 40's,
freezing multiple embryos and banking them for future use has the advantage of preserving
embryos while the patient is younger and more likely to have genetically normal embryos. In
some cases, these embryos may represent the only opportunity to patient may have to conceive
in 2-3 years when she is ready to have another child. ln addition, laboratories performing the
genetic studies usually charge only one fee when the genetic studies are all run at the same
time.
Until an easier, less invasive, less costly approach to embryo selection becomes available, PGS
utilizing one of available platforms for chromosome analysis, remains a powerful tool for
improving implantation rates and decreasing miscarriage rates.