For immediate release: Feb. 26, 2007
GALVESTON, Texas - Because the threat of genetic birth defects is still very real, says Dr. Neena Champaigne of UTMB's Division of Clinical Genetics, prospective parents who fall into several broad categories definitely should seek genetic counseling and screening before starting a family.
"Around two to three percent of all babies are born with birth defects," notes Champagne. That number hasn't changed much over the years, despite advances in prenatal health care.
Women who are over 35, or who have histories of multiple miscarriages should seek counseling, as should women and men who have family histories of genetic conditions such as birth defects and mental retardation. This advice also applies to members of specific ethnic groups. Caucasians, for example, should be screened for cystic fibrosis and African-Americans for sickle cell anemia. Cajuns and Ashkenazi Jews (Jews of eastern European descent) should be screened for Tay-Sachs disease.
"Genetic counseling offers a personalized risk assessment so couples can make informed choices for a healthy pregnancy," according to Champaigne.
Basic screening for at-risk populations should take place in the obstetrician's office, ideally before conception. Women whose screening results raise questions can then come to UTMB for "more invasive" genetic testing, such as chorionic villous sampling, in which a tiny tissue sample is taken from outside the sac where the fetus is developing. CVS yields the same results as an amniocentesis, but the prospective parents get the results five or six weeks earlier.
Champaigne said CVS is a bit riskier than amniocentesis, as the procedure bears a somewhat higher risk of miscarriage, but it and all other forms of prenatal genetic testing allow a head start to prospective parents who have serious decisions to make. "If an abnormal condition is identified, usually nothing can be done to correct the anomaly," Champaigne said. "But it's good to be prepared. It provides information to parents so they can make a decision based on their values and beliefs."
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