Chorionic Villus Sampling
Chorionic Villus Sampling (CVS) is a specialized prenatal diagnostic procedure used to test for certain chromosomal and genetic conditions during early pregnancy. A small sample of tissue called chorionic villi is collected from the placenta under continuous ultrasound guidance and sent to a laboratory for genetic testing. CVS is usually performed between 11 and 14 weeks of pregnancy, depending on the clinical situation.
Ultrasound-Guided Procedure
Specialized Genetic Testing
Chorionic Villus Sampling
Chromosomal Conditions
Genetic Conditions
Fetal Genetic Information
High-Chance Screening Results
Ultrasound Findings
Previous Pregnancy History
Family History
Specific Genetic Disorders
Chromosomal Analysis
Genetic Counselling
When Is It Recommended?
CVS is not routinely required for every pregnancy. It is generally offered when there is an increased chance that the baby may have a genetic or chromosomal condition.
- It may be offered following a high-chance prenatal screening result.
- It may be recommended when an ultrasound scan identifies a potential fetal abnormality.
- It may be considered when there is a previous pregnancy affected by a genetic or chromosomal condition.
- It may be recommended when there is a known family history of a specific inherited disorder.
- It may be considered when one or both parents are known carriers of certain genetic conditions.
Important Information
CVS is an invasive prenatal diagnostic procedure and should be undertaken only after appropriate counselling and discussion of its benefits, limitations and potential risks.
- CVS is a diagnostic test for specific genetic or chromosomal conditions; it does not test for every possible fetal condition.
- CVS cannot detect neural tube defects such as spina bifida; these are generally assessed through ultrasound and other appropriate investigations.
- Because the sample comes from the placenta, a small number of results may require further investigation or confirmation with amniocentesis.
- CVS can cause miscarriage. Current NHS information estimates the risk at less than 1 in 200 for most pregnancies, with the risk being higher in some multiple pregnancies.
- Rare complications can include infection, bleeding or an inadequate sample requiring repeat testing.