Routine Ultrasounds Unnecessary, Study Says : Medicine: The tests provide little benefit to 80% of all mothers-to-be, researchers find.

Routinely giving ultrasound scans to all pregnant women, as many doctors recommend, is unnecessary and may waste more than $1 billion a year, a research study concludes.

Researchers found that 80% of all mothers-to-be are at such low risk that they do not need ultrasound unless problems arise.

“Doctors using their judgment about when to order ultrasound tests results in just as good care as doing it routinely,” said Dr. Bernard Ewigman of the University of Missouri, principal author of the study.

Ultrasound has become an essential tool for steering women through difficult pregnancies. Sound waves produce an image of the fetus that can help doctors judge its age and growth and spot birth defects and other problems.

This is the first large-scale test of whether routinely providing such a test will mean safer pregnancies for all women, not just those at high risk.

The research involved 15,151 pregnant women in 109 obstetrical and family practices in six states. The results were published in Thursday’s New England Journal of Medicine.

The women were randomly assigned to two groups. In one, every woman got two routine scans. In the other, ultrasound was used only if a doctor felt it was necessary.

Forty-five percent of the women in the group that did not get routine ultrasound ended up getting at least one scan during their pregnancies.

In the study, 350 fetuses had major defects. Ultrasound found 35% of the defective fetuses carried by women getting routine scans, compared with 11% among those who were scanned only as necessary.

However, more than half of the defects spotted in the routinely scanned women were found too late for them to get abortions. As a result, the number of abortions was similar in the two groups--12 among the women getting regular scans and nine among those in the comparison group.

“From a policy standpoint, this is an example of the kind of excessive testing that is so pervasive in health care,” Ewigman said. The six-year, $7-million study is the largest to examine ultrasound’s benefits in pregnancy. It was financed by the National Institute of Child Health and Human Development.