GSN Races to Improve Prenatal Tests for Genetic Conditions

In 2003, Matthew Rabinowitz’s sister, then 32, gave birth to a baby boy with Down syndrome, who died six days later. While pregnant, she had routine tests for possible problems -- blood screening and an ultrasound -- but they failed to detect the extra chromosome that causes the condition.

Even when combined, these tests can have a 15 percent false negative rate, according to California’s Department of Public Health and data from Quest Diagnostics and LabCorp. “In other words, one in six pregnant women carrying a baby with Down syndrome will test negative and not know it,” says Rabinowitz.