Chorionic Villus Sampling—Transabdominal
Pronounced: kohr-ee-ON-ik vil-uhs sam-puhl-ing trans-ab-DAH-me-nahlEn Español (Spanish Version)
Chorionic villus sampling is a test that is done during early pregnancy to test for chromosomal abnormalities in the fetus. It involves removing chorionic villi from the placenta. The placenta is the organ that provides nutrients and oxygen to the baby during pregnancy. It also removes waste from the baby’s blood. Chorionic villi is the tissue that makes up most of the placenta. The test is done during the 9th-13th weeks of pregnancy.
Nine Week Old Fetus in Utero
Copyright © Nucleus Medical Media, Inc.
Chorionic villi contains valuable information about the baby’s genes. By testing chorionic villi, the doctor can find out if the baby has a chromosomal abnormality, like Down syndrome. The test can also detect genetic disorders, like cystic fibrosis. It cannot detect neural tube defects, such asspina bifida.
This test may be considered when:
- Other tests, such as a first trimester ultrasound or blood tests reveal abnormal results
- A prior pregnancy had a chromosomal abnormality
- The mother is 35 years old or older
- You or your partner is a carrier for a genetic disorder
- There is a family history of a genetic disorder
Although a test showing a healthy baby without a genetic disorder is ideal, you will need to be prepared if the results show otherwise. If the test shows that your baby may have a genetic disorder, it may require you to make tough decisions regarding your pregnancy, such as whether or not to continue it. If you do continue with the pregnancy, you will need to address concerns, such as planning for a child with special needs. Your doctor can help you understand the pros and cons of having this test, as well as talk to you about options after you know the results.
Last reviewedMarch 2014by Andrea Chisholm, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.