Questions About Down Syndrome

A government recommendation to screen all unborn babies for Down syndrome may be overkill, according to a new study. The study, published in the current issue of British Medical Journal, shows the tests may be less effective than screening based on a woman’s age.

The National Screening Committee in the United Kingdom government mandated that by 2004 all pregnant women should be offered blood tests to increase the detection of Down syndrome prior to delivery. Their intent was to reduce the number of medical procedures performed on the baby. There are two invasive tests that can be performed to detect the disease — amniocentesis and chorionic villus sampling. Both pose risks to the unborn child.

Researchers previously thought blood tests to screen for Down syndrome were more effective than screening based on the age of the woman. However, there have been no studies to prove this theory. In this British study, doctors found 15 percent of pregnant women were over 35 years old. This was more than the presumed number of 5 percent to 7 percent. Nearly 60 percent of babies with Down syndrome were born to women in that age category.

Doctors believe there is not enough evidence to mandate blood tests be given to all women. Instead, they write, “To avoid continuing the confusion that Down’s screening currently causes in pregnant women, we believe new screening methods should be offered only as part of a controlled study until their benefit is proved.”

SOURCE: British Medical Journal, 2002