Earlier Prenatal Screening for Down Syndrome

Pregnant women might benefit from a screening test that can be given earlier during pregnancy.

Currently, prenatal screening for Down syndrome using maternal blood cannot be performed in the U.S. before the 14th week of pregnancy. Researchers at Baylor College of Medicine will soon evaluate a screening test that can be performed between the 10th and 14th week of pregnancy for a multicenter study funded by the National Institutes of Health.

The new procedure requires an ultrasound exam and a blood sample from a fingerprick. The ultrasound measures the space behind the baby's neck that, when larger, often correlates with an increased risk for Down syndrome. The blood sample is analyzed for two chemicals associated with the genetic disorder. These results, in combination with the mother's age and the baby's size, can be used to project the likelihood of Down syndrome. If a high risk is determined, the mother will be offered prenatal testing that can confirm the presence or absence of Down syndrome. Approximately one in 700 kids is born with this form of mental retardation which is caused by an extra chromosome.

"By performing the test for Down syndrome during the first trimester, we hope to provide mothers-to-be either earlier detection or earlier reassurance, depending on the results," says Katie Leonard, a genetic counselor at Baylor.

- From Baylor College of Medicine

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Courtesy of Texas Medical Center News

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©2006 Texas Medical Center

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