Voice-over:
Each year more than forty-five-thousand babies are born with the aid of reproductive technologies like in vitro fertilization. Screening embryos for genetic diseases before they are implanted offers prospective parents the best chance for a healthy child, but some practitioners are questioning whether the test is accurate enough.
Voice-over:
University of Florida researchers took a closer look at preimplantation genetic diagnosis, which screens embryos for hereditary diseases such as down syndrome and other birth defects before they are implanted. To do this, one cell is extracted from an eight-cell embryo and examined for chromosomal defects. But some practitioners are concerned a single cell might not accurately represent an embryo's overall health. That could prompt doctors to discard an embryo unnecessarily, or implant one that ultimately will fail to develop. U-F researchers used a mathematical model and experimental data to assess the precision of the screening's findings. They concluded that ninety-nine percent of the time preimplantation diagnosis does correctly indicate which embryos are healthiest.
Dr. Ken Drury / UF Preimplantation Geneticist
"It gives our colleagues, I think, a much better tool to understand how their diagnosis may play a critical role in their ability to choose the right embryo to create a healthy pregnancy."
Voice-over:
Researchers say that when it comes to estimating how an embryo will develop, a phenomenon called mosaicism often raises red flags. The study showed that some early embryos can have one or two abnormal cells, yet still form properly. U-F researchers concluded that only about one percent of embryos are mistakenly implanted with undetected genetic defects not fifty percent, as some have feared, reaffirming the test's important role.
Dr. Ken Drury / UF Preimplantation Geneticist
"This way it is possible to diagnose the embryo prior to actually establishing a pregnancy and freeing the couple from the anguish of going through this whole procedure and having a poor outcome in the end."
Voice-over:
At the University of Florida Health Science Center, I'm Mike Garrison
