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A new test to reveal a baby's gender revives an old ethical dilemma

January 19, 2010 |  1:56 pm

For couples trying to have a baby, the No. 1 question that can be answered with a simple test is, Am I pregnant? No. 2 may soon be, Is it a boy or a girl?

Baby For years, reliable answers could only be provided by invasive tests such as amniocentesis and chorionic villus samplingEntrepreneurial genetic testing companies have sought an easier alternative. They claim they can identify a baby’s gender just weeks after conception by looking for signs of the male-only Y chromosome in a pregnant woman’s blood (if they find it, the baby must be a boy; if not, it’s a girl).

The problem is that such direct-to-consumer tests – which aren’t regulated by the Food and Drug Administration or the Federal Trade Commission – are frequently wrong. As we reported in a 2008 story, the biological principle behind the tests is sound, but the ability to actually find evidence of a Y chromosome in maternal blood varies widely. For example:

In a 2004 study, five medical centers in a National Institutes of Health consortium received identical blood samples from 100 women who were 10 to 20 weeks pregnant.

The centers used the same method to look for Y chromosomes in the maternal blood, but none was able to detect all of the 35 fetuses known to be male. According to the study, the detection rates ranged from 31% to 97%.

Now a team of Dutch researchers reports a new method for screening maternal blood and reports 100% success in determining a baby’s gender as soon as seven weeks after conception.

The study included 201 pregnant women whose blood was drawn between 2003 and 2009. The test produced conclusive results in 189 cases, and all of those results were correct. The findings were published in the January issue of the journal Obstetrics & Gynecology.

The idea behind the test isn’t simply to give parents extra time to start painting the nursery pink or blue. It’s to help screen for genetic disorders that are sex-linked. For instance, Duchenne muscular dystrophy and the blood clotting disorder hemophilia are tied to problems with the X chromosome and thus are almost always seen in males (since they only have one copy).

The blood test results made a difference for some of the women in the study. According to this report from Reuters:

Among the 156 women who underwent testing because of the risk of an X-linked disorder, the results allowed 41 percent to avoid further, invasive procedures to test for the disorder.

Another 27 women in the study were at risk of giving birth to babies with a genetic disorder called congenital adrenal hyperplasia, which causes girls to develop like boys. To prevent that from happening, the women began taking a steroid called dexamethasone as soon as they knew they were pregnant. But they were able to stop once the gender test revealed that their fetuses were male, according to Reuters.

But just because the test is accurate doesn’t mean it’s risk-free. Some prospective parents might take the results into account in deciding whether to continue a pregnancy, especially if they were hoping for a baby of a particular sex.

Bioethicist Arthur Caplan of the University of Pennsylvania said such tests are fraught with ethical problems. Even if doctors recommend the test to screen for a legitimate medical condition, it could “lead to abortions for non-medical reasons,” he told MSNBC.

With such concerns in mind, the Dutch researchers emphasized that “the test should be applied carefully in a clinical setting upon medical indication."

-- Karen Kaplan

Photo: Boy or girl? A blood test can tell you just a few weeks after conception, according to a new study. Credit: Los Angeles Times

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Comments (6)

Someone who would abort for non-medical reasons after a non-invasive, early test is just as likely to abort after a later and/or more invasive test, no?

Some people seem to have a need to mention elective abortion in a sort of knee jerk fashion, to remind us that it exists. I find it a distraction from an otherwise very interesting story.

In particular, the focus on tailoring treatment for minimal risk is a real insight into the potential for personalized medicine. It also emphasizes that the proper use of a test can lead to decreased, rather than increased, medical costs. How about more on that aspect of the story?

This interesting article is marred by the ignorant conflation of "gender" and "sex". Chromosomes may determine biological sex, but the relation to gender identity is much more complex and Times readers deserve not to be misled on this point. Karen Kaplan uses "sex", correctly, on several occasions in this post, so it's very disappointing to see "gender" used synonymously with "sex" elsewhere in the article - and particularly irksome for this usage to crop up in the headline which is promoted throughout the Times site and beyond.

JFS, how would this lead to decreased medical costs without abortion? We could decrease medical costs by killing older disabled members of our species too. Abortion is therefore the foundational issue before we move to other questions.

Especially given the discrimination against females in the ancient world and in various Asian cultures, we should worry that technologies like this will foster the growing movement of sex-selection abortions in the developed West:

Look how well sex selection has worked for the chinese. They have now come up on a wall, an entire generation of males unable to find a wife. Perhaps Prop 8 will be their savior.

It must be more than coincidental that the LA Times has an entire section featuring pregnancy and stories like this ("Bioethicist Arthur Caplan of the University of Pennsylvania said such tests are fraught with ethical problems. Even if doctors recommend the test to screen for a legitimate medical condition, it could “lead to abortions for non-medical reasons,” he told MSNBC.") on the anniversary of Roe v. Wade.

Totally disappointing, Times.

Sex determination by simple methods such as blood testing to detect Y chromosomes constitutes real challenge in the Indian milieu where it will be used to get rid of female offsprings. The law banning pre-natal sex determination, in force since 1994, is already under huge pressure and despite best efforts State is not able to enforce it fully. This is because of people's preference for male child, rooted in religious, cultural and socio-economic considerations. Prof. Kaplan's apprehension that the test can “lead to abortions for non-medical reasons" is well founded. There is an immediate need to evolve suitable and effective regulatory mechanism to stop its misuse.


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