Compared to amniocentesis, the new screen is done earlier, it's less invasive, and it doesn't increase the risk of miscarriage. Compared to the triple screen, the new test is done earlier and may be more accurate. Passas received a rare inconclusive result from the new test and went on to have amniocentesis, which showed no problems. She still believes the new test could be an important medical advance. The new test is among several emerging alternatives to amniocentesis, which still is offered routinely to women age 35 or over because they have a greater risk of having a child with Down syndrome.
Doctors generally consider amniocentesis safe and low-risk.
But women don't take it until the second trimester, when they look and feel very pregnant. If they get bad news, their decision about whether to end the pregnancy is all the more difficult and public. Researchers hope the new test will help more women avoid amniocentesis. If it proves more accurate, the new test also would detect more defects, especially among pregnant women under age 35. Because these women have the most babies, they have the most babies with Down syndrome.