August 10, 2011

Blood Test Determines Sex Of Child Early In Pregnancy

While some parents choose to wait to find out their their baby's sex, others are keen to know as soon as possible. Now, a team from the Tufts University School of Medicine have found a simple blood test that can provide early and accurate results, according to various media reports.

Testing for small pieces of the male sex chromosome in the mother's blood reveals if a mother is carrying a baby boy as early as seven weeks into the pregnancy. Researchers also said the test may be particularly valuable for families that harbor sex-linked genetic disorders like hemophilia.

"It could reduce the number of invasive procedures that are being performed for specific genetic conditions," study author Dr. Diana Bianchi told Reuters and The Daily Mail.

Because such disorders mostly strike boys, knowing that the baby is a girl could spare the mother diagnostic procedures, such as amniocentesis, that carry a small risk of miscarriage. A couple might be concerned, for example, if they already have one child with this kind of disorder, USA Today's Liz Szabo reports.

Less than 1 percent of couples are at high risk for these rare disorders, Joseph Biggio, director of the Trimester Genetics Screening Clinic at the University of Alabama-Birmingham, who wasn't involved in the new study, told Szabo.

Early sex tests are used routinely in the Netherlands, the United Kingdom, France and Spain currently, and some companies market them directly to consumers on the internet, Bianchi says.

US hospitals generally don't offer them. However, because the tests require sophisticated labs and with pristine conditions, to avoid contaminating blood samples, says James Goldberg of the California Pacific Medical Center in San Francisco. Although the tests aren't regulated by the Food and Drug Administration (FDA), Goldberg predicts this may change, as the tests become widespread.

The technology raises serious ethical concerns, Arthur Caplan, director of the Center for Bioethics at the University of Pennsylvania, told Szabo. Female fetuses are commonly aborted in India, he says.

A recent analysis in The Lancet estimates that between 4.2 million and 12.1 million female fetuses were "selectively" aborted in India from 1980 to 2010, a practice that is noticeably skewing the ratio of boys and girls in that country.

"What you have to consider is the ethics of this," explains Dr. Mary Rosser at the Montefiore Medical Center in New York. "If parents are using it to determine gender and then terminate the pregnancy based on that, that could be a problem. Remember, gender is not a disease."

The study is published in the currrent issue of JAMA.


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