NBC NEWS — A blood test may be a safe and effective way of finding out a baby's sex before birth.

Researchers from the national institutes of health looked at data on Cell-Free Fetal DNA taken from mom's blood after 7 weeks gestation. The test was able to predict the sex of the baby 95% of the time.

Doctors say this could someday be a useful and less invasive alternative to amniocentesis, which carries a risk for miscarriage.