Researchers announced some surprising results at this weeks meeting of the American Society for Reproductive Medicine. According to BBC News, several scientists reported that a high number of abnormal embryos are being produced by young healthy women.
Three U.S. studies were presented at the meeting. The first was a study done by Dr. Jeffrey Nelson of the Huntingdon Reproductive Center in California. Using an IVF check technique called PGD (preimplantation genetic diagnosis), Dr. Nelson screened 289 embryos from 22 egg donors, all of whom were healthy and under the age of 30. He found that 42% of the embryos had abnormal chromosomes.
Dr. Peter Nagy and his colleagues at Reproductive Biology Associates in Atlanta compared the rate of chromosome abnormality between younger (under 35) and older (over 38) women. Nearly two-thirds of the embryos produced by the younger set of women had abnormalities, and the number jumped to nearly three-quarters among the older women.
The third study came from the Shady Grove Centre of Preimplantation Genetics in Maryland. They found that eggs from healthy donors, whose ages spanned from 21 to 31, had a 52% chance of genetic abnormality.
Until these studies, many health care providers thought that eggs from younger women were more likely to be free of abnormal chromosomes. Dr. Nagy stated that the defects should not be present in such a high proportion of patients.
According to Canada’s The Gazette, researchers aren’t sure what’s causing the degeneration, but suggest culprits may include genetic predisposition, environmental factors, or the in-vitro fertilization process itself.
Researchers stated that the rate of problematic IVF embryos mirrors the real world, where it’s estimated that over 60% of pregnancies are lost before a woman even realizes that she is pregnant.