Fertility Preservation: Egg Freezing by Geoffrey Sher, MD
By Geoffrey Sher, MD
Women who want to preserve their fertility for reasons of cancer treatment, career, or other personal choice, have faced a difficult barrier due to the poor success rates for egg freezing. Pregnancy rates for women using frozen/thawed eggs have been less than 4% for each individual egg frozen. This is due to the fact that; 1) at least 60% of eggs frozen are chromosomally abnormal from the outset and therefore cannot produce a normal embryo and; 2) traditional (slow) egg freezing techniques commonly cause ice crystal formation within the cell structure, reducing viability or destroying the cells in the process.
A recent published breakthrough by SIRM and its affiliate, ReproCure (Genetics), addresses both of these issues, markedly reducing the downside of egg/embryo freezing. It involves CGH, the method described above for identifying all the chromosomes in the cell .
First, using proprietary CGH process-technology, eggs are tested for their chromosomal integrity prior to freezing, ensuring that only the “competent” ones are frozen. Second, a new method of ultra-rapid freezing (recently modified by ReproCure) called “vitrification” is used, allowing much more successful freezing without ice crystal formation. Through this CGH/Vitrification combination, we have been able to achieve post-thaw pregnancy rates that are more than 8 times higher per egg stored than previously reported methods.
At SIRM/ReproCure we have transferred embryos derived from CGH-tested eggs and embryos to more than 300 women resulting in >100 births and as many pregnancies still ongoing, thereby accounting for more CGH-derived pregnancies than the rest of the ART world combined. We are convinced that use of this technology will progressively grow and within the next 5-10 years will a “new standard of care” in the ART arena.
This exciting breakthrough, published recently in the medical journal “Reproductive Biomedicine Online” has opened the door to viable fertility preservation (FP) for women. We are now offering egg freezing and banking services at SIRM offices nationwide.