A prenatal pill for congenital adrenal hyperplasia to prevent ambiguous genitalia may reduce the chance that a female with the disorder will be gay. Critics call it engineering for sexual orientation.

Each year in the United States, perhaps a few dozen pregnant women learn they are carrying a fetus at risk for a rare disorder known as congenital adrenal hyperplasia. The condition causes an accumulation of male hormones and can, in females, lead to genitals so masculinized that it can be difficult at birth to determine the baby's gender.

A hormonal treatment to prevent ambiguous genitalia can now be offered to women who may be carrying such infants. It's not without health risks, but to its critics those are of small consequence compared with this notable side effect: The treatment might reduce the likelihood that a female with the condition will be homosexual. Further, it seems to increase the chances that she will have what are considered more feminine behavioral traits.