New Technique Increases IVF Chances
The world of the designer baby has just taken another step closer to reality. Changing the world with the first IVF baby, also known as the test-tube baby, more than 30 years ago and then again last year with the first “breast-cancer-free” baby, today they have provided another scientific breakthrough with the first egg-screening baby. British scientists have just created the technology enabling doctors to check eggs for chromosomal defects before fertilization.
Oliver is the first baby ever produced using Array Comparative Genomic Hybridisation (Array CGH). This advancement is quite an achievement and will be welcomed by fertility doctors. Defects in eggs and chromosomal aberrations in embryos are responsible for many miscarriages and failed IVF attempts.
During ovulation, the egg has to remove duplicate copies of its chromosomes to give space for the male sperm chromosomes during fertilization. The discarded egg chromosomes are contained in a small cell called a polar body. Sometimes, something goes awry, producing an egg which has too many or two few chromosomes. Down’s Syndrome or trisomy 21 is due to an extra 21 chromosome in the fertilized embryo. About 50% of female eggs have defective chromosomes. This increases dramatically as the woman ages and could be up to 75% by the time she reaches 39.
In an IVF cycle, embryos are pre-screened before implantation, usually through visual screening under the microscope. However, this pre-implantation screening method does not seem to increase IVF success. Enter Array CGH. Array CGH performs an “inventory” of the chromosomes in the polar body counting them to determine whether the egg has the right number of chromosomes. This method is much more reliable than simply looking at the embryo. The test takes 1 to 2 days to complete after which only the chromosome defect-free embryos are used and implanted. It is estimated that the chances of success during an IVF procedure are increased two- fold. What is interesting is that the scientists who develop the method reported that healthy, defect-free eggs are not necessary the “best looking” when viewed under the microscope, casting further doubt on visual egg screening.
Oliver’s mom is 41 years old and is of advanced maternal age through no fault of hers. She had three miscarriages and 13 failed IVF attempts. Late last year, the doctors screened 8 of her eggs using, Array CGH and only 2 were found to be normal. One of those eggs was fertilized, implanted and produced Oliver. It is truly amazing what technology can do. Be prepared to see more advancements and wider use of this technique.
