Moms Can Find Out Baby's Sex at 7 Weeks

Parents dying to know the sex of their baby may no longer have to hold their breath until halfway through a pregnancy. A blood test can reveal a baby’s sex as early as seven weeks into a pregnancy, Reuters reports—which is earlier than many doctors will see patients for an initial prenatal visit.

The blood test, called a cell-free DNA test, has been used by European doctors for years and has actually been available to American consumers in drugstore chains and online for a few years, but the accuracy of the test was unknown. The simple test analyzes fetal DNA in the mother’s blood, looking for traces of the male ‘Y’ chromosome. News of the surprising accuracy of the test (98.8 accuracy for a boy and 94.8 accuracy for a girl) was originally reported yesterday in a meta-analysis of 57 studies published in the Journal of the American Medical Association.

 Doctors hope the test (which costs a few hundred dollars, including lab fees and shipping costs) will help families with a history of sex-related genetic disorders such as hemophilia (which tends to affect boys) avoid unnecessary invasive procedures, like chorionic villus sampling or amniocentesis, that carry a small risk of miscarriage. And, in fact, in England, where the test is already in use, many moms are already skipping invasive tests, thanks to this blood test.

Plus: Am I Having a Boy or a Girl? Fun Ways to Tell

Not everyone welcomed news of the test, though, given the ethical issues it raises; a number of people have already voiced concerns that knowing a child’s sex so early in a pregnancy could lead to gender selection through abortion.

Plus: Early Signs of Pregnancy

Would you take the blood test to learn your baby’s sex? Would you buy such a test online, or would you only do it with your doctor’s approval?