PGD can screen for genetically transmitted diseases, such as such as cystic fibrosis, Tay Sachs disease, hemophilia, Fragile X syndrome, Barth's syndrome and Rett's syndrome.

PGD is a genetic testing tool that allows for the analysis and transfer of healthy embryos back to the uterus. A single cell from an 8-cell embryo is removed and subjected to a number of DNA probes. Using PGD, reproductive scientists now can determine whether an embryo has extra or missing chromosomes, or aneuploidy.

Lawrence B. Werlin, founder and director of California-based Coastal Fertility Medical Center, presented his findings on the use of PGD at the annual American Society of Reproductive Medicine conference (ASRM).

The Genesis study looked at the chromosomal make-up of an embryo before implanting it into the uterus. Since in vitro fertilization (IVF) is an expensive, exacting procedure, the new study supports the use of PGD to select only those embryos with the highest likelihood for success.

Another study reconfirmed earlier findings that PGD helps facilitate successful pregnancy for women considered to be high-risk because they suffered from recurrent pregnancy loss, and/or were over age 38. This study found that approximately 75 percent of the embryos in the high-risk group had two or more chromosome abnormalities.

Since a vast percentage of first-trimester miscarriages occur due to chromosomal abnormality, PGD can help reduce the risk of miscarriage.

According to the March of Dimes, chromosomal and/or genetic anomalies are either solely (13%) or partially (up to 20%) to blame for up to one-third of the 150,000 babies born with a birth defect each year. What