Can it be ethical to give girl fetuses a drug to prevent ambiguous genitalia when the drug may also influence their sexual preferences in later life? The US researchers involved reject the idea of using the drug to “treat” homosexuality.
New Scientist explores what's behind the story.
What is the treatment, and what is it used for at present?
The treatment is for a condition called congenital adrenal hyperplasia (CAH), which affects about 1 in 15,000 babies. Fetuses affected by CAH have gene defects which mean that they either can't make or don't make enough of a key adrenal hormone called 21-hydroxylase.
That means that their adrenal glands carry on producing male hormones long after they should have stopped. Boys' sexual organs are not affected by this, but about one in eight fetuses that are at risk of CAH will be female and develop genitalia with masculine characteristics, such as a large clitoris. Girls may also have their urethra positioned inside the vagina, for example.
At birth doctors and parents may have difficulty deciding the gender of girls affected this way, and many go on to have surgery to correct the physical abnormalities. But a group of researchers led by Maria New of the Mount Sinai Medical Center in New York have been testing a treatment that prevents the anatomical abnormalities in the womb. It means giving a pregnant woman at risk of having a child with CAH a drug called dexamethasone (dex) starting as early as five weeks after conception. The drug keeps male hormones at a normal level, reducing the possibility of the anatomical defects, though it has no effect on their CAH – people with the disorder will continue to take medication throughout their life.
How might such a treatment stop girls being gay?
The majority of girls with CAH are heterosexual. One of the hallmarks of girls who have CAH is that they are more likely to be tomboyish, to avoid having children in adulthood, and are slightly more likely than the average girl to be gay or bisexual.