Preliminary Statistics for CCS
If you have been following Fertility Flash newsletters, you may have noticed several recent articles about Comprehensive Chromosomal Screening (CCS). CCS is the process of analyzing blastocyst-stage embryos for chromosomal make-up. This process helps to ensure that embryos transferred to a patient have the proper number of chromosomes (i.e. 46XX or 46XY) and do not have abnormalities that could result in failed implantation, miscarriage or an abnormal fetus at the time of amniocentesis or birth. We at Pacific Fertility Center have taken the lead in developing and promoting CCS for many of our patients. 2012 was a banner year for the emergence and application of this technology for patients undergoing in vitro fertilization.
The tables below, labeled Table A and Table B, represent the preliminary data on the first several hundred embryos we have biopsied, sorted by the age of the egg provider. It demonstrates what we have known all along: eggs and embryos are more likely to have abnormal numbers of chromosomes as patients get older. In this table, OD refers to eggs from ovum donors.
As Table B illustrates, 76% of the embryos from egg donors are normal, whereas only 11.54% of the embryos from women 43-44 years of age are normal. The previous column is also important: of women 43-44 years of age who had embryos to biopsy, only 18% had ANY normal embryos to transfer. This result is consistent with the low delivered pregnancy rates with conventional IVF in this age group. However, for women less than 43 years, the overwhelming majority of treatment cycles that continue to biopsy will have at least one normal embryo to transfer.
Please note that the data on the right only include patients that had normal embryos at biopsy and therefore were able to have an embryo transfer. Not included are those patients with only abnormal embryos.
We look forward in 2013 to continued leadership in this exciting new area of assisted reproduction. We believe that this technology will lead to greater success for our patients; a result of lower miscarriage rates and fewer instances of termination of pregnancies due to chromosome abnormalities.
- Carolyn Givens, M.D.