Study could spur wider use of prenatal gene tests

In those cases, "a lot of couples might not be happy that they ordered that test" because it can't give a clear answer, she said.

Ana Zeletz, a former pediatric nurse from Hoboken, N.J., had one of those results during the study. An ultrasound suggested possible Down syndrome; gene testing ruled that out but showed an abnormality that could indicate kidney problems — or nothing.

"They give you this list of all the things that could possibly be wrong," Zeletz said. Her daughter, Jillian, now 2, had some urinary and kidney abnormalities that seem to have resolved, and has low muscle tone that caused her to start walking later than usual.

"I am very glad about it," she said of the testing, because she knows to watch her daughter for possible complications like gout. Without the testing, "we wouldn't know anything, we wouldn't know to watch for things that might come up," she said.

The other study involved 532 stillbirths — deaths of a fetus in the womb before delivery. Gene testing revealed the cause in 87 percent of cases versus 70 percent of cases analyzed by the visual chromosome inspection method. It also gave more information on specific genetic abnormalities that couples could use to estimate the odds that future pregnancies would bring those risks.

The study was led by Dr. Uma Reddy of the National Institute of Child Health and Human Development.

Read more: Medical journal at http://www.nejm.org

Marilynn Marchione can be followed at http://twitter.com/MMarchioneAP