Washington, DC,
USA — It's the first question new parents hear:
girl or boy? But hundreds of babies are born each year
where the gender isn't clear. Prompt surgery to assign
one was once the norm.
But gender depends on
more than anatomy or hormones. It also seems to stem from
the very earliest brain development, researchers said
Friday in urging doctors to hold off on the knife until
children can determine their own sex.
"To discover who or what
a child is ... you have to ask them," Dr. William Reiner
of the Oklahoma University Health Science Center
<http://www.ouhsc.edu/>
told a meeting of the American Association for the
Advancement of Science <http://www.aaas.org/>.
"There is no one
biological parameter that clearly defines sex," added Dr.
Eric Vilain of the University of California, Los Angeles,
whose research suggests gender is genetically hard-wired
into the brain before birth — regardless of which
genitalia develop.
The issue is "intersex,"
the name for numerous conditions that result in roughly
one in 4,000 babies born with both male and female
traits.
One of the more common is
congenital adrenal hyperplasia. In such cases, genetic
girls with XX chromosomes are exposed in the womb to such
high levels of androgen — the hormone that triggers
male development — that they appear male externally
even if they have female reproductive organs. A different
condition leaves genetic males less responsive to
androgen during development, so they're born without a
penis.
The parents must pick a
gender somehow, to know what to call their child and
because gender is required on a birth certificate. So
specialists check non-obvious factors such as which sex
chromosomes the child has and levels of sex hormones in
the blood.
But Dr. Vilain's research
suggests there are factors at work that can't be
measured. The scientific dogma used to be that hormones
alone could "masculinize" the brain, he said. But he
identified 54 genes that work differently in the brains
of male and female mouse embryos just 10 days after
conception — before sex hormones are ever
produced.
Doctors also once thought
that how people were raised and their genitalia were
enough to determine gender, said Dr. Reiner, who as a
urologist performed sex-assignment surgeries on
babies.
But he began seeing
children who had been assigned to one sex as babies and a
few years later began identifying themselves as the
other. He re-trained as a psychiatrist to study these
children.
His latest review of 94
intersex children found over half of the genetic males
"transitioned" to become boys despite being raised as
girls and undergoing female surgical sex
assignment.
How? As early as age 4
1/2, the children would suddenly say, "I'm a boy," or
pick a boy's name, he explained.
Hence his advice to
parents to think hard before agreeing to surgery for an
intersex baby: Dealing with the social trauma of
switching gender later is enough without the issue of
surgery that can't be reversed.
