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.
That such a treatment would ever be considered, even to prevent genital abnormalities, has outraged gay and lesbian groups, troubled some doctors and fueled bioethicists' debate about the nature of human sexuality.
The treatment is a step toward "engineering in the womb for sexual orientation," said Alice Dreger, a professor of clinical medical humanities and bioethics at Northwestern University and an outspoken opponent of the treatment.
The ability to chemically steer a child's sexual orientation has become increasingly possible in recent years, with evidence building that homosexuality has biological roots and with advances in the treatment of babies in utero. Prenatal treatment for congenital adrenal hyperplasia is the first to test — unintentionally or not — that potential.
The hormonal treatment "theoretically can influence postnatal behavior, not just genital differentiation," said Ken Zucker, psychologist in chief of the Center for Addiction and Mental Health in Toronto, who studies gender identity. "Some people refer to girls with CAH as experiments of nature because you've got this condition and you can take advantage of studying it."
Complicating the situation is the fact that the daily hormone pill does nothing to treat or cure the underlying condition, caused in this case by a defective enzyme in the adrenal gland.
Dreger and critics — which include the National Center for Lesbian Rights, Advocates for Informed Choice (an organization that works to protect the rights of people with intersex conditions), and some pediatric endocrinologists and parents of children with the condition — say far too little is known about the safety of the hormone, the steroid dexamethasone, when used prenatally. They say it should be used sparingly, in closely monitored clinical trials, or not at all. They're even more concerned that some doctors might tell parents that a reduced chance of homosexuality is one of the therapy's benefits.
"Most clinicians speak about this treatment as ambiguous-genitalia prevention," said Dreger, who co-wrote an editorial about the treatment in a July publication of the Hastings Center, a bioethics organization. "Others suggest that you should prevent homosexuality if you can. But being gay or lesbian is not a disease and should not be treated as such."
To that end, in September, a consortium of medical groups led by the Endocrine Society will release updated guidelines on treatment of congenital adrenal hyperplasia that acknowledge the controversy. The guidelines are expected to describe prenatal dexamethasone therapy — first used about 20 years ago, but now with increasing frequency — as experimental and reiterate that the standard approach for cases of ambiguous genitalia is to perform corrective surgery.
But they're not expected to discourage research on the treatment.
Congenital adrenal hyperplasia, caused by a defect in an enzyme called 21-hydroxylase, affects about 1 in 15,000 infants, and almost all newborns are screened for it. Undetected, the abnormality can make both male and female infants critically ill within a few weeks of birth because of an associated salt loss through the urine. The defective enzyme also causes a deficiency of the hormone cortisol, which can affect heart function, and an increase in androgens produced by the adrenal glands.
The excess presence of the male hormone testosterone in the womb has little effect on a male fetus' genitalia. Even in females, the anatomical defect may be mild, involving nothing more obvious than a slightly enlarged clitoris. However, in severe cases, girls are born with male-like sexual organs although they usually have ovaries and a uterus.