Picking the Best Embryo for IVF
Genetic Fingerprint Can ID Embryos Most Likely to Succeed
May 13, 2008 -- Genetic fingerprinting can find the best embryo in a batch, upping the odds of success for in vitro fertilization with just one implant.
In vitro fertilization, or IVF, has two major drawbacks. The first is that the early embryo doesn't always survive implantation into the womb. To overcome this, doctors often implant several embryos. That leads to the second drawback: multiple pregnancies, which endanger the mother as well as the fetuses.
Because of the problems posed by multiple pregnancies, there's been a trend toward IVF with just a single embryo. But there's no standard way for doctors to pick the embryo most likely to succeed from the others in a batch.
That may soon change. Doctors already can "biopsy" a few cells from early embryos without hurting them. Now researchers at Australia's Monash University show that DNA fingerprints from these cells provide valuable information about the embryo's chances of becoming a baby.
"The ability to select the single, most viable embryo from within a cohort available for transfer will revolutionize the practice of IVF," study researcher Gayle M. Jones says in a news release. This will "not only improve pregnancy rates but eliminate multiple pregnancies and the attendant complications."
Jones and colleagues got genetic fingerprints from early embryos before they were implanted into 48 women undergoing IVF. They also got genetic fingerprints from the 37 babies born to these women, allowing them to tell which embryos succeeded and which failed.
Genetic screening showed that genes involved in several processes that are key to successful implantation -- cell adhesion, cell communication, cellular metabolism, and cell responses to stimuli -- were particularly active in the successful embryos.
"We are developing this technology in order to encourage single-embryo transfer to all patients with a degree of confidence that the embryo being transferred is the best among those available," Jones told WebMD in an email interview.
Larger studies will be needed to fine-tune the technique. These studies will compare the genes of successful embryos to those of failed embryos. Such studies should give doctors the genetic-fingerprint profile of embryos destined for success.
"I expect that it will be at least two years from now to know the genes that are most predictive and to have refined this to a simple laboratory test that can be performed within the clinics," Jones says.
George Attia, MD, director of reproductive endocrinology and infertility at the University of Miami, is familiar with the work of Jones' team. Attia was not involved in the study.
"It is an exciting new idea," Attia tells WebMD. "It is still very early, but it is a promising idea. This would give us a more objective way to judge which embryos will implant and which will not."
Jones and colleagues report their findings in the May 14 online issue of Human Reproduction.