Embryo Selection

Most methods of determining which embryo to transfer to the uterus during In Vitro Fertilization rely on a visual assessment under the microscope.  The prettiest embryo wins.  Unfortunately, this approach ignores the most common cause of IVF failure - chromosomal abnormalities.  Doctors can't tell by simply looking at an embryo whether it is chromosomally "competent."  If an embryo has too many or too few chromosomes, it will either fail to develop, result in a miscarriage, or be manifest as a birth defect.

Until recently, the only method available for analyzing the number of chromosomes in an embryo was a process called FISH (Fluorescence In Situ Hybridization).  The problem with FISH is that it only analyzes 8-12 of the 23 chromosome pairs in an embryo.  This leaves more than half of the chromosomes unaccounted for and therefore falls short as a reliable method of embryo selection.

The recent introduction at Sher Institutes for Reproductive Medicine (SIRM) of a remarkable new technology called CGH (Comparative Genomic Hybridization) now allows analysis of every pair of chromosomes in the embryo for numerical abnormalities.  For the past 2 years, we've been studying this process and organizing the resources to perform the highly complex test in our own genetics laboratory.  When we applied this technology to the IVF process to select "competent" embryos, the results were remarkable.  To date, more than 100 women have undergone IVF with us using this method and more than 60% have achieved pregnancies!  This is about twice the national average per embryo.

For more information about CGH, click here: