New tests, which can determine sex earlier in pregnancy, are rekindling the debate over selective abortion.

The tests function as early as seven weeks into pregnancy, safely within the threshold for use of less-invasive abortion procedures, including the abortion pill RU-486. The relative convenience of having an abortion at seven weeks, combined with expected tests for genetic disabilities, raises the unpleasant specter of eugenics: aborting fetuses with “unwanted” characteristics.

While they shouldn’t be banned, the new genetic tests make fighting discrimination — and providing greater opportunities for all Americans — an imperative.

Sex-selective abortion is an easy bugbear. The image conjured up by anti-abortion advocates is that of a selfish, wealthy woman who wants a boy or a girl so badly that she is willing to abort fetuses until she gets one with the “right” sex. But this stereotype — aside from preying on misogynist caricatures — is implausible at best; that sort of shallow narcissistic sex-selection is more suited to designer fertility clinics.

Sex-selective abortion arises out of sexism, not fashion. Cultures in which men are more able to provide for aging parents, or in which women are considered to be members of their husband’s family, are more likely to spawn discriminatory abortion.

And the hysteria about sex-selection (which has engendered laws in Arizona and Oklahoma outlawing the practice) ignores a more controversial practice: the selective abortion of fetuses with disabilities, which would also be facilitated by an earlier chromosomal test.

Even more than 25 percentof anti-abortion Americans support legalizing the abortion of fetuses that have “mental impairments” or “physical impairments,” according to a Gallup poll (pro-choice respondents, of course, overwhelmingly supported the legality of such a practice). A 1999 study found that more than 90 percent of American women who were carrying a fetus with Down syndrome chose to abort. The data are old, but no similar study has been conducted in recent years; there’s no reason to suspect that the proportion has decreased.

And thus children with Down syndrome, and the mothers who choose to keep them, are relegated to be tokens of the anti-abortion movement — women who are supposedly “self-sacrificing” enough to give birth to a child with disabilities.

Having a child with Down syndrome should not sound like martyrdom. It does, though, which indicates something seriously wrong with our society.

That something is a lack of societal support and acceptance of people with disabilities. Disabled children require more time, energy, and money; disabled adults frequently have limited options, particularly if they require costly care or devices. While some support exists in the form of the social safety net, there are frequent allegations of neglect or abuse; last month, mentally disabled Iowa men who worked for a poultry producer for 41 cents an hour were awarded more than $1 million in back pay by a federal judge.

We need to both increase institutional opportunities and value the humanity of people with disabilities within our society.

There are valid reasons to test for Down syndrome, spina bifida, and even a fetus’ sex early in the pregnancy. Parents may need to make special arrangements for a child with disabilities or may want to know if they are going to have a boy or a girl (although the sheer weight of gender norms in infancy is disturbing on its own). But when these scientific tests are combined with a culture that does not value or nurture variations in ability or sex, there is a clear recipe for discriminatory and unethical use.

Scientific procedure is a tool that can lead as much to a reification of social norms as a rejection of them. Eugenics isn’t about technology but about the society that uses it. If increased genetic testing leads to sex-selective and disability-selective abortions, we must nip these in the bud by fighting the devaluation of certain human lives.