Pregnancy

The Woman During Pregnancy: Possible Problems and Complications:
Prenatal Tests

Chorionic villus sampling (CVS)
This procedure takes cells from the chorionic villi, i.e. tiny fingerlike projections on the placenta. It is usually performed between the 10th and 12th week of pregnancy if there is a risk of certain genetic disorders. Chorionic villus sampling has the advantage of allowing an early diagnosis.
The sample is taken though a needle which is guided by ultrasound. The needle may be inserted through the abdomen or, very early in the pregnancy, through the vagina. Analyzing the results takes about one month. The sampling is not entirely unproblematic for the expectant mother who may run a slightly higher risk of miscarriage than would otherwise be the case. Therefore, some women pefer not to have this test.