Chorionic villus sampling (CVS) is a diagnostic test usually performed between 11-14 weeks of pregnancy. This test will provide you with a definitive (yes or no) assessment about chromosome disorders in the pregnancy, such as Down syndrome. This test can also test for some other genetic disorders for pregnancies considered to be at an increased risk.

Using high-resolution ultrasound for guidance, the physician will either insert a needle through your abdomen or will insert a small catheter through the cervix to the placenta (depending on the location of the placenta). A small sample of chorionic villi (cells from the placenta) is removed to complete the testing.

Chorionic villus sampling is performed earlier in the pregnancy than amniocentesis, so results are returned sooner. However, a CVS is unable to test for open neural tube defects, such as spina bifida. However, testing can be completed with a simple blood test in the second trimester where they measure a protein in your blood called AFP. Open neural tube defects can also be screened for during your anatomy scan around 20 weeks of pregnancy.

Preliminary results will be available 2 to 3 days after your procedure. Final results will be ready 10 to 14 days following your CVS. Results occasionally take longer. If you do not have your results in fourteen days from the procedure, feel free to contact us. When calling, please be sure to leave phone numbers where you can be reached late in the day.

Genetic counseling is recommended to anyone considering CVS or any prenatal testing.

Some of the most common reasons patients consider undergoing chorionic villus sampling are:

  • Age 35 or older at delivery
  • A previous child with a chromosome abnormality or an identified genetic disorder
  • A parent carries a balanced chromosome translocation (rearrangement)
  • Both parents are carriers for the same genetic disease (for example: Tay-Sachs, sickle cell anemia, and many others for which we have genetic testing available)
  • An abnormal First Trimester Screen or cell-free DNA screening (also known as NIPT) indicating that the pregnancy is at an increased risk for a chromosome disorder
  • Finding of a fetal abnormality on ultrasound

Chorionic Villus Sampling Aftercare

In general, you should be able to resume most daily activities after CVS. You may return to work, as long as your job does not require excessive physical activity. The following general guidelines will help with follow-up care:

  • For 5 to 7 days after your procedure:
    • Stay off your feet as much as possible
    • No lifting over 10 pounds
    • No exercise or strenuous activities
    • No sexual intercourse or sexual activity
    • Drink extra fluid
    • If one or more of the following occur, please let us know before the procedure: constipation, excessive sneezing, coughing.
    • Additional instructions for women having transcervical chorionic villus sampling:
      • No douching
      • No use of tampons
      • No tub baths; showers are fine
  • Commonly experienced symptoms after chorionic villus sampling:
    • Spotting or brownish discharge with transcervical chorionic villus sampling
    • Minor bruising or soreness at the area of insertion with transabdominal chorionic villus sampling
    • Mild cramping for 24 to 48 hours (if you wish, you may take Tylenol for this discomfort)
  • Complications to watch for:
    • Vaginal bleeding
    • Foul smelling discharge, passage of clear fluid, or tissue from the vagina
    • Heavy cramping
    • Fever or Chills
  • If complications occur:
    • Bed rest is recommended
    • Call your obstetrician first. Your obstetrician may choose to contact us directly, or you may feel free to call our office and speak with our nurse at 301.279.6060.