March of Dimes Medical Director Appears on CBS Early Show to Discussion New Research on Prenatal Screening

FEBRUARY 16, 2005 -- March of Dimes medical director Nancy S. Green, M.D., appeared this morning on The CBS Early Show to discuss new research that may lead to simpler, more precise prenatal screening.

Research published today in the Journal of the American Medical Association shows potential for DNA analysis of fetal cells that typically cross the placenta during pregnancy and circulate in the pregnant woman's blood.  This could lead to the development of a simple blood test that could reduce the small but real risk to mother and fetus from more invasive diagnostic procedures such as amniocentesis (which carries risk of a serious complication of considerably less than 1 percent).

The JAMA paper describes a new technique to help detect fetal genetic disorders non-invasively.  In a test done on samples of the mother's blood, researchers in Switzerland were able to separate and identify the fetal DNA, and through it, determine the risk for the genetic blood disorders known collectively as beta-thalassemia. The researchers analyzed samples from 32 women at risk for the disorder and were able to correctly determine whether the gene mutation used for diagnosis of beta-thalassemia was present from the fetal DNA in 80 to 100 percent of the cases.  The researchers say the study proves that fetal genetic traits can be detected from the analysis of fetal DNA in the mother's blood, and add that the blood test is relatively simple and cost-effective.

Dr. Green says this development also may open the door to a greater understanding of genetic causes of disease.

The March of Dimes urges women considering pregnancy to have a preconception medical checkup with their health care provider, at which time they should review their health status, family history, and current medications.  And all women of childbearing age should consume 400 micrograms of the B vitamin folic acid every day, by taking a multivitamin and eating a healthy diet, to prevent serious birth defects of the brain and spine known as neural tube defects.

"Detection of Paternally Inherited Fetal Point Mutations for Beta-Thalassemia Using Size-Fractionated Cell-Free DNA in Maternal Plasma," by Ying Li, Ph.D., and others, appears in the February 16 issue of JAMA, volume 293, number 7.