You guessed it.....Chorionic villus sampling!

Ultrasound Review of Obstetrics and Gynecology had a great article in the December 2003 issue about chorionic villus sampling history and risks. The opportunity for testing chorionic cells gained ground in the 1970's and initial attempts were made to introduce CVS. It was confirmed that chorionic tissue obtained with a hysteroscopic device at 9-10 weeks of gestation was suitable for cytogenetic testing of the fetus. In the 1980s it became apparent that chorionic tissue sampling permits the diagnosis of monogenic diseases in the first trimester. Diagnosis in the first trimester offers advantages such as reduced emotional and physical strain on couples belonging to high-risk groups, assurance of the greatest possible discretion regarding the pregnancy, and a decreased maternal strain in the case of a possible spontaneous abortion. The increase of the use of CVS slowed down at the beginning of the 1990s when a possible relationship was hypothesized between CVS and fetal limb defects. But studies have not found any firm evidence of a link.

Since then the demand for CVS has increased again in recent years. One of the consequences of the developments that have taken place in the field of molecular genetics is that gene defects leading to particular illnesses are now being identified in an ever-increasing number of disorders. This permits fetal diagnosis at gene level via fetal DNA testing for an ever-larger group of illnesses. Since chorionic cells are more suitable for molecular genetic testing (as well as enzyme diagnosis) than amniocentesis.

CVS can be performed in two ways: transcervically(through the cervix) and transabdominally (through the abdomen). Both of these approaches are done under ultrasonographic control. It is suggested that the transabdominal procedure is done but it also depends on the position of the baby.

C Papp (2003). Chorionic villus sampling. Ultrasound Review of Obstetrics and Gynecology, 3(4), 279-284. Retrieved February 21, 2008, from Research Library database. (Document ID: 548015861).