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New Data on Genetic Testing of Embryos Before Transplantation Shows Reduction in Miscarriages and Improved Chance of Normal Pregnancy LIVINGSTON, NJ -- New data reveals that with genetic testing prior to implantation, the rate of miscarriage is significantly reduced, from 23% to 9%, and pregnancy rates in infertile couples increased, according to the latest research from the Institute for Reproductive Medicine and Science at Saint Barnabas Medical Center in Livingston, N.J. The procedure, termed Preimplantation Genetic Diagnosis (PGD), also decreases the chances for chromosomal abnormalities, such as Downs syndrome. In women who experienced repeated miscarriages, the rate went from 100% to only 15%. PGD is performed routinely at only a few centers in the United States. PGD involves removing a single cell from a three-day-old embryo and testing it for chromosomal disorders. Abnormal embryos can be removed, leaving only the healthy ones for transfer. The obvious advantage of PGD, states Jacques Cohen, Ph.D., Scientific Director of Assisted Reproduction at the Institute, is the reduction in the chance of having a baby with chromosomal abnormalities. Equally significant, says Cohen, are the dramatic decrease in repeated miscarriages and the increase in pregnancy rate following PGD. “This new data shows great promise for our in-vitro fertilization patients, especially those over 35, who have been disappointed by repeated miscarriage and unexplained failure to conceive,” states Cohen. Santiago Munné, Ph.D., Director of Implantation and Genetics at the Saint Barnabas Institute, has been one of the leading pioneers of PGD in the world. According to Munné and the researchers at the Institute for Reproductive Medicine and Science at Saint Barnabas, the primary reason that the chances of pregnancy diminish with age is the presence of chromosomal abnormalities. Some chromosomal abnormalities, called aneuploidy, occur in all women, says Munné, but more frequently in women over age 35. Aneuploidy, means one extra or one missing chromosome, and can result in embryo death and infertility, spontaneous abortions or babies with Down syndrome or other chromosome abnormalities. Other defects are called translocation, which is when a chromosome, or part of a chromosome, moves to a wrong position. Translocations are inherited, and have been found to be the cause in about 9% of repeated miscarriages. The new evidence suggests that by removing the abnormal embryos prior to transfer, the healthy embryos have a much better chance of implanting and continuing to grow into a viable pregnancy. The procedure is very intricate, Munné explains. About two days after fertilization, a gap is made in the outside shell (zona pellucida) of the embryo and one or two cells are removed by gentle aspiration. The procedure does not seem to affect the normal development of the embryo nor does it cause further inconvenience to the patient. The biopsied cells are analyzed using a technique called fluorescence in-situ hybridization, which attaches different fluorescent colors to each of the nine chromosomes able to be tested. Says Munné, “Very soon we will be able to test for all 23 pairs of chromosomes using this technology.” Dr. Munné reported these findings on the advantages of PGD at a recent meeting of the European Society of Human Reproduction in Bologna, Italy. In addition to performing cases at Saint Barnabas, including patients referred from IVF centers throughout the United States, Dr. Munné has performed PGD on 200 patients in Italy over the last two years. “Worldwide testing provides statistics from different populations and enables researchers to gather the most accurate and conclusive data on PGD,” states Munné. The goal of The Institute for Reproductive Medicine and Science at Saint Barnabas Medical Center is to help its patients achieve viable, healthy pregnancies. “Preimplantation Genetic Diagnosis (PGD) is a relatively new technology that is helping to make a significant difference in achieving this goal for our patients,” states David Sable, M.D., Director of the Division of Reproductive Endocrinology at Saint Barnabas. “We feel strongly that this procedure will bring significant change to the field by decreasing the chances of miscarriage and abnormal fetuses and increasing the chances for pregnancy among an already challenging patient population.” For further information about Preimplantation Genetic Diagnosis (PGD), please contact the Institute for Reproductive Medicine and Science at Saint Barnabas Medical Center at (973) 322-8286. [ top ] |
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