Oct. 15, 2010 -- Three babies born to two 40-year-old women in Europe are the first IVF babies born from eggs screened for chromosomal abnormalities using a fast new DNA test.
IVF -- in vitro fertilization -- often fails. A major reason is that implanted eggs have abnormal chromosome numbers. This is a particular problem for women over age 37, for those with previous IVF failures, and for those with previous miscarriages.
Current methods of screening eggs for chromosomal abnormalities don't help and may make IVF less successful. Both U.S. and European reproductive medicine groups advise against the practice.
Now there's a fast new way to look for abnormal chromosomes that doesn't harm the embryo. It examines DNA from polar bodies -- cells ejected from eggs during early development.
Unlike earlier pre-implantation genetic screening techniques, polar body screening does not require freezing the eggs until results become available.
In a European pilot study reported last June, the technique was nearly 90% successful in identifying chromosomal abnormalities. It resulted in a 33% pregnancy rate per egg transfer in 40-year-old women.
In the U.S., the live birth rate per egg transfer is just over 28% for women age 38 to 40, and just under 17% for women age 41 to 42.
Now the first three babies born from IVF using the new technique have been born -- a pair of twins born in Germany last June and a boy born last month in Italy.
"All the babies and their mothers are doing very well in terms of weight and overall developmental performance," says Cristina Magli, MD, of the SISMER Center in Bologna, Italy, in a news release.
While the new screening technique is a definite advance, it's just one more step in a march toward better IVF success rates, says William E. Gibbons, MD, president of the American Society for Reproductive Medicine and professor of obstetrics and gynecology at Baylor College of Medicine.
"We are hoping to get better and better and better at embryo selection," Gibbons tells WebMD. "This means we will be able to reduce the number of embryos transferred in each procedure, and that we will be able to reduce the multiple-birth rate. Being able to improve the efficiency of IVF and lowering IVF complications is a big deal."
The European Society of Human Reproduction and Embryology is gearing up for a large-scale clinical trial to evaluate the new screening technique.