When doctors told Marybeth Scheidts and David Levy they knew which embryos would result in a pregnancy through in vitro fertilization, the Philadelphia couple was thrilled.
"They just said, 'These are the great embryos. You'll have a baby,'" Levy, 41, said. "That's all we cared about."
What the pair didn't know was that when baby Connor arrived on May 18, he was the first child born through a new screening technique that identifies which embryos created by IVF are most likely to lead to successful pregnancies.
Current chromosome-screening tests are expensive, but an international team of researchers led by an Oxford doctor say the "next-generation sequencing" techniques will make the tests widely available. The screenings sequence a small part of an embryo's DNA to determine the number of chromosomes present; embryos with an abnormal number of chromosomes typically don't lead to a pregnancy.
"Many of the embryos produced during infertility treatments have no chance of becoming a baby because they carry lethal genetic abnormalities," Dr. Dagan Wells, the lead researcher, said in a statement. "Next-generation sequencing improves our ability to detect these abnormalities and helps us identify the embryos with the best chances of producing a viable pregnancy."
Scheidts, a 36-year-old mortgage banker, and Levy, a registered nurse, tried intrauterine insemination, a different fertility treatment, three times before signing up for IVF at Main Line Fertility, which is based in Bryn Mawr.
The couple had 13 IVF embryos to choose from. Cultures from each were sent to Wells at Oxford for genetic screening.
Most of the embryos appeared to be healthy, but just three had the correct number of chromosomes. One of those embryos was used, and Connor Levy was born in May.
Because of the new screening, their doctors "were highly confident that one would take" and advised against implanting multiple embryos, Levy said.
The couple froze the remaining two embryos, in case they want to expand their family later.
Dr. Michael Glassner, the Main Line Health System physician who worked with the couple, said he believes such testing will become routine. The screenings will boost pregnancy rates for couples going through IVF, and reduce miscarriages, he said.
Just about one-third of embryos chosen through standard protocols generate a pregnancy, according to data from the Centers for Disease Control and Prevention.
Especially in older women, a chromosome can "look perfect," but still be abnormal, Glassner said. The testing will allow doctors to detect those abnormalities, and the higher success rates may ease some patients' concerns about IVF.
"For a lot of patients, there's a fear of failure, a fear of the unknown," he said.
The new sequencing method is also less labor-intensive than current procedures, making it less expensive, Glassner added.
"It's just a remarkable test," he said.
That's a good thing for couples like Levy and Scheidts, who had looked into chromosome testing because of their difficulties while trying to conceive. But existing screening methods would have cost $6,000, and "we just couldn't afford that," Levy said.
A second couple also had the testing done; their baby is scheduled to be delivered in a few months.
Wells says he plans to conduct a randomized clinical trial to further evaluate the effectiveness of the approach.
Wells is outling the technique at this week's annual meeting of the European Society of Human Reproduction and Embryology.