WHAT IS CCS?
CCRM is pleased to offer comprehensive chromosomal screening (CCS), which is also known as preimplantation genetic testing for aneuploidy (PGT-A). CCS is performed in conjunction with IVF and is particularly important for women 35 years of age or older whose eggs are at increased risk for chromosome errors. An estimated 70% of early miscarriage is associated with a chromosomal abnormality in the fetus.
CCS is performed on a few cells biopsied from a day 5 embryo called a blastocyst. The genetic material of the embryo is not altered in any way during CCS. During the time it takes to perform CCS, blastocysts are cryopreserved using a quick freezing method called vitrification. Embryo survival after vitrification is extremely high at 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. Studies have shown that transferring embryos into a uterus that is in a more natural hormonal state enhances the likelihood of implantation and a healthier outcome.
After CCS, only embryos that have the correct number of chromosomes are selected for transfer.
WHO SHOULD CONSIDER CCS?
CCS is not recommended for all infertility patients. Those who may consider CCS include the following:
- Women 35 years of age or older
- Women with a history of repeated miscarriage
- Women with a previous pregnancy involving a chromosomal abnormality
- Women who have had multiple failed IVF cycles
NEXT-GENERATION SEQUENCING (NGS)
Next-generation sequencing is the latest technological breakthrough in pre-implantation genetic testing. NGS allows us to study all 23 pairs of chromosomes at a more comprehensive level and with deeper resolution. CCRM’s CCS lab extensively validated the accuracy, reproducibility and reliability of this revolutionary new CCS NGS platform (VeriSeq™ by Illumina).
CCRM is aware that there are other IVF clinics and reference labs publicly reporting discrepancy with anueploid embryos (chromosomally abnormal). We want to assure our patients that our CCS lab runs at the highest level of expertise with strict quality control and data analysis to enable accurate CCS diagnosis of IVF embryos. As part of our ongoing commitment to excellence, we routinely reconfirm diagnosis on aneuploid embryos to better understand the incidence of chromosome abnormality.
Recently, CCRM dual biopsied 90 aneuploid blastocysts (day 5 embryos) and blindly analyzed the CCS results to reveal 96% accuracy. The remaining 4% were mosaic aneuploid embryos (containing both chromosomally normal and abnormal cells) that would never have resulted in a healthy live birth. This sampling is larger than any of the recent published studies. CCRM has biopsied over 30,000 embryos with only 2.3% returning with evidence of mosaicism. CCRM delivers the highest rates of chromosomally normal embryos for our infertility patients.