| Early amniocentesis offers a similar advantage, but the fetal loss rate associated with this technique is higher than that of chorionic villus sampling. |
| Prenatal tests called amniocentesis and chorionic villus sampling can diagnose Tay-Sachs before birth. |
| Another prenatal test, called chorionic villus sampling, can diagnose most, but not all, of the same birth defects as amniocentesis. |
| Current diagnosis of fetal aneuploidy is based on karyotyping fetal cells obtained from amniocentesis or chorionic villus sampling. |
| Using chorionic villus sampling techniques, examination will in many cases be possible as early as the 10th week in the near future. |
| The only definitive test involves chorionic villus sampling and amniocentesis but that carries a risk of miscarriage. |
