It's a boy! It's a girl! Until the 1970s, these words welcomed virtually every child into the world. In less than one generation, however, new reproductive technologies have shifted this announcement from the delivery room to the obstetricians' office; ultrasounds and amniocenteses now allow expecting parents to choose their nursery walls' paint color months before giving birth.

The science and business of sex identification took yet another quantum leap forward this past week with the Pregnancystore.com's release of the Baby Gender Mentor Home DNA Gender Testing Kit. Now, a woman can know her child's sex shortly after she discovers her pregnancy. As soon as five weeks after conception, she can prick her finger, FedEx a blood sample to Acu-Gen Biolab in Lowell, MA, and have the sex of her sprouting embryo emailed to her faster than Netflix can send her next movie.

An unequivocal good, many say. What's more harmless than learning whether to buy dolls or trucks for the toy chest?

Ultrasounds and amniocenteses cannot accurately determine a fetus' sex until at least four months into pregnancy and sometimes not until month five - a point at which virtually all expecting mothers have already chosen to continue their pregnancies to term. Since the State has no legal interest in a fetus before its viability (usually at 24 weeks), there has been a legal and technological gulf separating a woman's choice to continue her pregnancy and any knowledge of its sex.

This is no longer the case. With the Gender Mentor Kit, a new issue enters many prospective parents' minds: Do we want to have a child of this sex? Or should we try again?

Are there many people who would reason, and act, in this way? There are. Nobel prize winning economist Amartya Sen estimates that such sex selective practices are, in part, responsible for over 100 million "missing women" worldwide. But since dowries and other culturally specific influences fuel boy preference in places like China and India, many, including Pregnancystore.com president Sherry Bonelli, believe that this "isn't an issue in the United States."

Or is it? Sex selection in the United States is becoming a multi-million dollar industry. Businesses such as MicroSort, a sperm sorting service that selects for sex before pregnancy, are part of an ongoing commercial effort to normalize sex selection as Extreme Makeover normalizes cosmetic surgery. To be sure, the Gender Mentor Kit does this while also providing a wholly new economic incentive: where sperm sorting costs in upwards of $5000, the Gender Mentor Kit plus an early term abortion - if the results are unfavorable - would cost as little as $600.

In some regards, Ms. Bonelli may very well be correct. Since most Americans conceive children in a different cultural and economic context than their Chinese and Indian counterparts, there may be little reason to think that sex selection in America would lead to an imbalanced sex ratio. Yet, defending sex selection in this manner is little more than a straw man; its ethicality should not turn solely upon sex ratios, but ought to look at the act itself. America's foreseeable sex ratio speaks little to the broader principle of whether sex should inform procreative decisionmaking.

Some advocates argue, as Rutgers Law Professor Kimberly Mutcherson told Newhouse News Service, "if you believe women have the right to choose, [selecting sex] is a perfectly legitimate reason." Yet this perspective, as a matter of law, is of questionable merit. Subsuming an ostensible right to select sex under Roe's reproductive freedoms is as misguided as the Gender Mentor Kit's mistaking sex for gender. The right to choose neither includes nor implies a right to design; Roe secures a woman's decision to "bear and beget a child," not a right to configure its human attributes.

What, then, is the appropriate response?

Our laws afford women a right to privacy with regards to their decision to carry a pregnancy to term. Yet, allowing for-profit corporations to change the nature of this 'private' decision will undoubtedly have a 'public' impact; at least 15 countries - including England, Australia, Canada, Germany, and France - proscribe sex selection for this very reason. This is not to suggest any new limits on Roe, nor resurrect or legitimate any old ones. Rather, it is to put forward the idea that there is a dubious relationship between embryonic sex identification and sex selection that leads us one step closer to a new eugenics. To the extent that the Gender Mentor Kit does little outside of lending more ice to a slippery slope towards designer babies - where a child's physical, emotional, and mental attributes are pieced together in a Frankensteinish manner - we ought to think long and hard about whether "mentoring gender" is a recipe for disaster.

Osagie Obasogie, J.D., is project director with the Center for Genetics and Society's Project on Race, Disability and Eugenics.