Thomas Jefferson University Hospital
 
CENTER FOR MATERNAL-FETAL MEDICINE

Jefferson Center for Maternal-Fetal Health

Jefferson physicians helped pioneer Chorionic Villus Sampling.  We are one of the most experienced perinatal labs in the country performing CVS and have been offering this important procedure since 1984.  Patients travel to us from across the United States as well as abroad to have their CVS performed by our perinatologists.  Our ultrasound lab is AIUM (American Institute of Ultrasound in Medicine) accreditated.   This accreditation is the hallmark of an ultrasound practice that meets nationally accepted standards of patient care, demonstrates consistent excellence, and is current with the latest ultrasound technology.

 

Chorionic Villus Sampling

  • Chorionic Villus Sampling is a method of prenatal diagnosis, which has been utilized since 1983. The major benefit of chorionic villus sampling is that it provides genetic diagnostic information early in the pregnancy.

  • The purpose of CVS is to obtain a sample of cells from the developing placenta that may be used to test for fetal chromosome abnormalities, such as Down syndrome, and/or other genetic conditions.

  • The optimal time for CVS testing is between 10-13 weeks gestation.

  • A discussion with a genetic counselor occurs prior to the CVS. During this discussion, the pregnancy and family medical histories are reviewed, as are the specifics of the CVS procedure and the plans for reporting results. Any special concerns and options for decision making are explored. CVS is performed only after the woman is fully informed and consents to the procedure.

  • CVS is performed as an outpatient procedure. The procedure involves taking a small sample of the developing placenta using ultrasound guidance. CVS may be performed as either a vaginal or abdominal procedure. Vaginal procedures are performed using a flexible catheter through the cervical canal. Vaginal CVS procedures feel similar to having a pelvic examination with slightly more abdominal pressure. Abdominal procedures involve using a very thin needle through the abdominal wall. Abdominal CVS feels similar to having an amniocentesis.

  • The perinatologist performing the CVS will determine the safest approach for the vaginal or abdominal CVS depending on the position of the placenta. Once the sample is obtained, it is carefully cleansed and transported to the laboratory for the appropriate analysis.

  • During the CVS procedure it is common for the woman to experience mild uterine cramping. This may be slightly uncomfortable, but it is usually not painful.

  • The standard laboratory testing performed on a CVS consists of a chromosome analysis (karyotype). Final chromosome results are >99% accurate and are usually available within 7 to 10 days. Certain laboratories perform a separate rapid study of some of the cells from the CVS. These results may be available in 48 hours. However, all preliminary results must be validated by the standard chromosome analysis (final results).

  • The CVS may detect a chromosome abnormality that is present only in the placenta (not in the fetus). This occurs 1-2% of the time. In these cases, further testing, such as amniocentesis, may be recommended. In addition, these pregnancies will be followed more closely due to the presence of abnormal cells in the placenta.

  • The accuracy of genetic testing results from CVS for other genetic conditions may be variable and is dependent upon the current limitations in testing for that particular condition. The amount of time for genetic test results is also variable.

  • CVS carries a small amount of risk for complications which can result in pregnancy loss. The procedure related risk for pregnancy loss is approximately 0.5% when performed at an experienced testing center, such as Thomas Jefferson University.

  • Normal test results do not guarantee the birth of a healthy baby. The general population chance for a birth defect is approximately 2-3%. Because CVS does not detect physical abnormalities, such as neural tube defects, a targeted fetal anatomy scan is recommended in the second trimester, usually at 18 - 20 weeks gestation. In addition, maternal serum alpha-fetoprotein levels can be checked in the second trimester to provide further screening for neural tube defects and/or placental complications.

  • Following a CVS procedure, it is recommended that the women refrain from strenuouns physical activity, heavy lifting, sitting in water (such as bath or pool), and sexual intercourse for approximately 24 - 48 hours.  Additional recommendations include avoiding the insertion of anything vaginally, including tampons, suppositories, or other for 24 - 48 hours.


  • The CVS testing center may request certain information from your physician prior to performing the procedure. The information needed includes: prior ultrasound reports, blood type, antibody screen (indirect coombs), gonorrhea and chlamydia cultures, and other relevant clinical information.

For more information, please contact the genetic counseling office at Thomas Jefferson University: (215) 955-0408.  To schedule an appointment, please call (215) 955-2112.