> without invading the fetal privileged space (which is what we currently do, and which is high-risk). [emphasis mine]
The standard process is amniocentesis, and according to wikipedia, that has a miscarriage rate "as low as 1 in 1600", plus an unspecified risk of infection. While that's almost certainly higher than the risk due to drawing the mother's blood, I wouldn't call it a "high-risk" procedure.
Would you feel the same way if the risk of death from a diagnostic test for cancer was 1/1600? The answer probably hinges upon the type of cancer, the treatment available, etc, but clearly this is not something you'd use for a population screening tool.
Up until ~4 years ago, the risk of miscarriage from amniocentesis was thought to be 1/200, but if the 1/1600 number is true, that's good. Nevertheless, it's not something that you're going to want to be doing to every pregnant woman. On the other hand, we draw plenty of blood from pregnant women, so we can essentially get this without additional risk to the fetus, except the risk of elective termination.
The standard process is amniocentesis, and according to wikipedia, that has a miscarriage rate "as low as 1 in 1600", plus an unspecified risk of infection. While that's almost certainly higher than the risk due to drawing the mother's blood, I wouldn't call it a "high-risk" procedure.