Diagnostic studies (amniocentesis, chorionic villous sampling CVS)
Chorionic Villus Sampling (CVS) and amniocentesis are diagnostic tests you may be offered to check if your baby has a genetic or chromosomal condition. These tests are not a screening tool but rather give complete and final information regarding the genetic makeup of the fetus.
A CVS is typically performed within the 10th to 13th week of pregnancy, earlier than amniocentesis. This procedure involves testing a small sample of cells from the placenta, which is the organ that links the mother's blood supply with her fetus and contains fetal genetic information. The sample can be easily taken through the cervix (trans-cervical) or the abdomen (transabdominal) without entering the amniotic sac or disrupting the membrane or the fetus.
Amniocentesis is a procedure that is performed after the 15th week of pregnancy in order to determine if the fetus has a genetic/chromosomal difference or an open neural tube defect (ONTD
If you have undergone a prenatal screening test that has indicated a heightened concern about your pregnancy, you may decide you would like to have a CVS or amniocentesis to alleviate anxiety and to understand the baby’s condition more clearly or to find relief that “everything is ok”.