Patients over 35

First Trimester
Screening

Amniocentesis

Chorionic Villus
Sampling

 


Chorionic Villus Sampling

Chorionic Villus Sampling - It is common for every pregnant woman to wonder whether her baby is healthy. In situations where a woman may be at increased risk for genetic or other health conditions, e.g. being 35 years or older, having an unexpectedly high or low AFP level or a history of certain genetic disorders), your doctor may suggest consideration of genetic counseling and chorionic villous sampling (CVS). In this situation, at Ocean Perinatology, we would recommend genetic counseling so that a person s detailed family history can be reviewed. Following this counseling, the patient/couple will know whether genetic testing is indicated and what genetic testing may be appropriate.

CVS is a procedure that involves obtaining a small fragment of the placenta (villous), via a tiny flexible catheter that is inserted through the cervix or via a needle inserted through the abdomen. Which route (transcervical or transabdominal), is depended upon the location of the placenta. The CVS sample is sent to the genetics lab where the test(s) appropriate for the woman s risk can be performed. Conditions that can be diagnosed via CVS include chromosomal problems (e.g. Down Syndrome, etc.), inherited conditions (e.g. Tay-Sachs, Sickle-Cell Anemia, etc.) and conditions which are influenced by the sex of the baby (e.g. Hemophilia).

CVS is performed in the ultrasound unit at Ocean Perinatology. The procedure is ultrasound guided and is usually performed at 11 1/2 - 12 1/2 weeks gestation. Under unusual circumstances it may be performed later, but a CVS is never performed at SDPC prior to 10 weeks gestation. Currently available information indicates that the risk of miscarriage after a CVS is 1 in 175-200. Following the CVS procedure, a person goes home to reduced activity for 24 hours; i.e. no working, exercising, or cooking. After this 24 hours, she can resume her normal activity. After a CVS a woman may have some mild cramping, but should not have severe cramping, fever or heavy bleeding. The CVS test results are typically available within 10-14 days. It is recommended that a person having a CVS have a follow up, high-resolution ultrasound at 17-18 weeks gestation and consider expanded AFP testing at 16-18 weeks gestation.

The major advantage of CVS relative to amniocentesis is that the CVS procedure can be done at 11 1/2 to 12 1/2 weeks of pregnancy as compared to 15 to 16 weeks for amniocentesis. A disadvantage of CVS relative to amniocentesis is that AFP testing is not done on the CVS specimen.