“In 2010, Dutch researchers reported that women who rely on low-sodium, high-calcium diets and who have intercourse in a particular window of time following ovulation can increase their odds of having a girl. The method is not foolproof, but what if it worked routinely? It would be hard to make the case that the method involved here, eating particular kinds of food, was objectionable in itself. It would be hard to make the case either that the motives of parents for wanting boys or girls are always objectionable. Unless there were some wild swing in the sex ratio caused by eating one’s way to children of the preferred sex, it would also be hard to make the case that this option would be objectionable in its effects either.
Human beings take steps all the time to order events in nature in ways that protect and enrich their lives. If the motives for selecting traits in children through prenatal interventions are not objectionable in themselves, if the interventions are safe and effective, and if no social harm comes from their use, it is possible to defend the selection of traits in children and maybe even, sometimes, call it an obligation.”