An unusual finding in an experiment by two Boston-area doctors is raising questions about a new generation of prenatal screening tests used by an increasing number of pregnant women to predict the risk a fetus has Down syndrome or other genetic conditions. A pair of obstetricians at Boston Maternal Fetal Medicine who specialize in high-risk pregnancies submitted blood samples from two women who were not pregnant to five commercial labs that perform these new screens, claiming the samples were from women who were 12 weeks pregnant. The study was funded by Ariosa Diagnostics Inc., one of the testing companies. Read more.