For parents-to-be, impatient to know whether to paint the nursery blue or pink, a simple test can provide answers as early as seven weeks into the pregnancy.  These tests have been available for some time but weren’t widely used in the U.S., because their accuracy wasn’t known. Now, The New York Times reports, a new study in The Journal of the American Medical Association, has “found that carefully conducted tests could determine sex with accuracy of 95 percent at 7 weeks to 99 percent at 20 weeks.”

But is it really necessary to know your baby’s sex that early? For some parents, it can be.  The Times reports that European doctors routinely use such tests to:

… help expectant parents whose offspring are at risk for rare gender-linked disorders determine whether they need invasive and costly genetic testing. For example, Duchenne muscular dystrophy affects boys, but if the fetus is not the at-risk sex, such tests are unnecessary.

But the big downside, and one that concerns me greatly as a doctor and a mother, is that some cultures have such a bias against baby girls that the wide availability of such testing will result in ever more otherwise healthy female fetuses being aborted.

Several companies do not sell tests in China or India, where boys are prized over girls and fetuses found to be female have been aborted. While sex selection is not considered a widespread objective in the United States, companies say that occasionally customers expressed that interest, and have been denied the test. A recent study of third pregnancies in the journal Prenatal Diagnosis found that in some Asian-American groups, more boys than girls are born in ratios that are “strongly suggesting prenatal sex selection,” the authors said.
At least one company, Consumer Genetics, which sells the Pink or Blue test, requires customers to sign a waiver saying they are not using the test for that purpose. “We don’t want this technology to be used as a method of gender selection,” said the company’s executive vice president, Terry Carmichael.

Cultural preferences won’t be deterred by a signature on a form, but at least, it’s a start. At some point, all cultures will learn to value both genders equally. Until then, a test that holds promise for some, can be a terrible incentive for the ultimate act of bias against females in others.

– Yvonne S. Thornton, MD, MPH