Chorionic villus sampling
Chorionic villus sampling (CVS) is an antenatal procedure for prenatal diagnosis of chromosomal or genetic disorders in the fetus. It entails getting a sample of the chorionic villus (placental tissue) and testing it.
A transabdominal or transcervical approach is selected depending on the position of the placenta to avoid entering the amniotic cavity.
It is usually performed under ultrasound guidance and takes during the 10-12 weeks of gestation, earlier than amniocentesis (which is carried out as early as 14-16 weeks).
Potential risks
- miscarriage: 0.5-4% 1
- amniotic fluid leakage
- possible limb reduction defects: not proven in randomized controlled trials
Related Radiopaedia articles
Ultrasound - obstetric
- ultrasound (introduction)
- obstetric ultrasound
- first trimester and early pregnancy
- ectopic pregnancy
- multiple gestations
- subchorionic hematoma
- failed early pregnancy
-
second trimester
- fetal biometry
- fetal morphology assessment
- fetal echocardiography views
- non-visualization of the fetal stomach
-
soft markers
- nuchal fold thickness
- ventriculomegaly
- absent nasal bone
- choroid plexus cysts
- enlarged cisterna magna
- shortened fetal long bones
- echogenic intracardiac focus (EIF)
- echogenic fetal bowel
- aberrant right subclavian artery
- fetal pyelectasis / fetal renal pelvic dilatation
- single umbilical artery
- sandal gap toes
- amnioreduction
- Doppler ultrasound
- nuchal translucency
- 11-13 weeks antenatal scan
- chorionic villus sampling (CVS) and amniocentesis
- placenta
- other