Chorionic villus sampling is a diagnostic fetal test that uses a small sample of the placental tissue to test for chromosomal abnormalities and some other genetic problems in the growing fetus. The sample is extracted with the use of a long, thin needle, and the process is usually performed between the 11th and the 14th week of pregnancy. This minimally invasive, generally safe procedure has a small risk of miscarriage (0.5-1%). On the other hand, CVS allows for earlier decisions regarding possible termination of the pregnancy within the first 14 weeks, helping to reduce stress for the couple, support better emotional processing of the findings, and minimize risks to the mother.

What is Chorionic Villus Sampling?

CVS is an invasive diagnostic test conducted to detect genetic and chromosomal conditions such as:

  • Down’s syndrome (Trisomy 21)
  • Edwards’s syndrome (Trisomy 18)
  • Patau’s syndrome (Trisomy 13)
  • Genetic disorders such as thalassemia, cystic fibrosis

Chorionic Villus Sampling may be recommended if:

  • You’ve received a higher chance screening result from the NIPT or the nuchal scan
  • A genetic disorder runs in your family
  • You want a definite “yes” or “no” answer

When is CVS performed?

Between 11and 14 weeks of gestation, we take a small sample of tissue (chorionic villi) with a thin needle inserted through the abdomen of the mother. This is done under continuous ultrasound guidance. This procedure takes a few minutes and is performed only by highly experienced fetal medicine specialists.

 

Getting your results

There are two types of results:

  • Rapid test (QF-PCR) for the most common chromosomal conditions (trisomy 21, 18, and 13) is available in 2–3 working days.
  • A detailed analysis of all chromosomes (full karyotype or microarray) is available in 10–14 working days.

As a maternal-fetal medicine specialist (perinatologist), Professor Petros Nikolaidis will discuss the benefits and risks of CVS with you in full before you decide to consent and proceed.