TROPHECTODERM BIOPSY AND COMPREHENSIVE CHROMOSOME SCREENING
NYFI is now offering a new IVF service that dramatically improves implantation and live birth rates for infertility patients of advanced reproductive age and those who have had multiple failed IVF cycles or several miscarriages.
The service involves screening of embryos for chromosome abnormalities prior to embryo transfer. A large number of unsuccessful IVF cycles can be attributed to the presence of numerical chromosomal abnormalities in the embryos. Consequently, screening of embryos for chromosome abnormalities prior to embryo transfer can significantly improve pregnancy rates as well as decrease miscarriage rates.
We have previously relied on Preimplantation Genetic Diagnosis (PGD) to identify abnormal embryos. However, PGD testing, which is based on a one-cell biopsy followed by fluorescent in situ hybridization (FISH), permits less than half of the chromosomes to be screened. Recent studies have shown that between twenty and forty percent of all embryos carry chromosome abnormalities that could not be detected using FISH screens employed in conventional PGD. These undetected chromosome abnormalities in human embryos can be the cause of the unsuccessful IVF cycle.
The recently developed technology of Comparative Genomic Hybridization (CGH) paved the way for screening of the entire genome of the embryo for numerical chromosome abnormalities (also called comprehensive chromosome screening or CCS). This is the preferred method offered by us for Preimplantation Genetic Diagnosis (PGD). The technique as offered by us involves the removal of a few cells from a laser drilled hole on the shell of the day 5 or 6 embryo (blastocyst embryo). This is also referred to as trophectoderm biopsy. The biopsied embryo is not harmed by the technique and is frozen by a rapid and quick process called vitrification. The removed cells are analyzed for their entire chromosome complement.
Patients who may benefit from this technique include the following:
- Women 35 years of age or older
- Women with a history of repeated pregnancy loss
- Women with a previous pregnancy involving a chromosomal abnormality
- Women who have had multiple failed IVF cycles
- Couples with known translocations
- Couples desiring gender selection for family balancing
Using this technique, there is a lower error rate than traditional FISH methods performed on cells from earlier stage embryos. The pregnancy rate is also much improved. In addition to aneuploidies or numerical chromosome abnormalities, it is also possible to detect chromosome imbalances due to translocations (chromosomal rearrangements) that are present in some couples. Patients with known translocations can therefore benefit from application of this technology in detecting affected embryos prior to embryo replacement.
The gender of the embryos is also available through CCS. We also offer simple gender determination involving the removal or biopsy of one cell from a day 3 embryo and analyzing the sex chromosome complement using the technique of FISH. This does not require the freezing of the embryos and embryo replacement occurs as blastocyst transfer in the same cycle.
Patients who are interested in learning more about CCS and/or meet the criteria listed above may schedule an appointment. Please call 212-734-5555