Comprehensive Chromosome Screening (CCS):
New Technologies Screen for all 23 Pairs of Human Chromosomes

The Colorado Center for Reproductive Medicine (CCRM) is conducting a clinical trial screening for all 23 pairs of human chromosomes prior to embryo transfer. The new analytical technology, polymerase chain reaction (PCR), allows for the evaluation of all 23 pairs of human chromosomes on a single cell.  This comprehensive chromosome screening becomes particularly important to patients over 40 who are prone to chromosomal errors in their eggs, as well as those patients with a history of recurrent pregnancy losses with an otherwise normal evaluation or who have had multiple failed IVF cycles.

CCS is performed on a few cells removed from a day 5 embryo called a blastocyst.  During the time it takes to perform CCS, blastocysts are cryopreserved using a quick freezing method called vitrification.  Embryo survival after vitrification has significantly improved to 98%.

Waiting for the CCS results and vitrifying the embryos has an added benefit to the patient. It offers some time for the patient’s body to return to a normal hormonal state after ovarian stimulation from the previous IVF cycle. A variety of studies have shown that replacing embryos into a uterus that is in a more natural hormonal state enhances the likelihood of implantation.

This is a clinical study, but CCRM believes Blastocyst Comprehensive Chromosomal Screening (CCS) could be a promising and beneficial procedure for patients seeking to increase their chances of implantation and a live birth.  As the worldwide pioneers of blastocyst CCS we are delighted to announce over 500 healthy babies born and countless ongoing healthy pregnancies.

2010 Data -- Thawed Embryos from CCS Testing Patients

Why CCS?

An estimated 60% of all early miscarriages are associated with a chromosomal abnormality in the fetus. The purpose of CCS is to select and transfer only embryos that do not have numerical abnormalities for the chromosomes tested in order to achieve higher implantation rates and fewer pregnancy losses.

Research has shown chromosomal abnormalities in embryos may increase the risk of spontaneous miscarriage or the development of a genetically abnormal fetus in IVF pregnancies from the following indications: women 35 or older, couples with multiple-failed IVF cycles or implantation failure, and couples with repeated miscarriages.

Only embryos identified after screening as euploid are transferred. This should theoretically reduce the likelihood of implantation failure, miscarriage and/or aneuploid offspring.

Preimplantation genetic screening does have inherent false positives and negatives due to the limited number of cells available for testing. An inherent 10% error rate means that there is no guarantee of a healthy baby.  If a pregnancy is established, prenatal diagnosis in the form of an amniocentesis is highly recommended.