Fresh Hopes and Concerns as Fetal DNA Tests Advance

Doctors have started using powerful new DNA tests to screen fetuses for a wider range of genetic abnormalities, spotting more problem pregnancies early but stirring fears that the results will increase abortions as well as confuse and needlessly alarm many couples.

The tests, which use "gene chips" to detect much subtler chromosomal variations than standard prenatal testing can, have also triggered complaints that they mark another step toward a society that seeks to weed out aberrations in the quest for the perfect child.

Proponents argue that the tests allow couples to harness the latest molecular technology to target the most devastating genetic syndromes, alleviating their worries in some cases and in others identifying abnormalities soon enough to terminate the pregnancy or prepare to care for an afflicted baby.

But critics say the tests have not been thoroughly validated and threaten to produce a flood of murky, misleading results that will subject emotionally vulnerable couples to unnecessary anxiety, perhaps prompting some to abort healthy pregnancies.

Some worry that the technique could be used to hunt for the rapidly growing list of...