It used to be that a pregnant woman had to wait at least until the end of her first trimester (11-12 weeks) to get an early indication of the gender of the baby she was carrying. And that was with an invasive test such as chorionic villus sampling or amniocentesis that came with a potential side effect of miscarriage and was only used to detect potentially life-threatening diseases within the baby.
For most women, the first real chance to know the baby's gender is the ultrasound performed at 20 weeks (or possibly even after the baby is born). But now a new noninvasive blood test has been developed that can determine a baby's gender, with 95 percent accuracy, as early as the seventh week of pregnancy.
According to a new report about the test published today in the Journal of the American Medical Association, the blood test is already used in Europe and may be offered in the U.S. as soon as 2012.