# CVS — Chorionic Villus Sampling

Source: https://www.pregnancypowerhour.com/tests/cvs-chorionic-villus-sampling
Last updated: 2026-07-01

> Chorionic Villus Sampling (CVS) is an optional diagnostic test performed between weeks 10 and 13 to provide definitive information about your baby's chromosomes by sampling placental tissue.

Chorionic Villus Sampling (CVS) offers a way to gain definitive chromosomal information about your baby earlier in pregnancy than other diagnostic options. This test can bring clarity and help you make informed decisions about your care path.

## What it is

CVS is a diagnostic test, meaning it provides a definitive answer about certain chromosomal conditions, unlike a screening test which only indicates a higher likelihood. It involves taking a small sample of tissue from the placenta, which shares the same genetic makeup as your baby. This sample is then analyzed to identify chromosomal abnormalities. Many parents consider CVS when a prior screening test, such as NIPT, has returned a positive result, or when they simply desire a definitive answer about their baby's chromosomes in the first trimester. It's important to note that while CVS provides comprehensive chromosomal information, it cannot detect neural tube defects, a difference from another diagnostic test, amniocentesis.

## When and how it happens

CVS is typically performed between weeks 10 and 13 of pregnancy, making it an earlier diagnostic option than amniocentesis. The procedure can be done in one of two ways: transabdominally (through your abdomen) or transcervically (through your cervix). Both methods are guided by ultrasound to ensure precision and safety. While any medical procedure carries some considerations, the miscarriage risk associated with CVS is roughly 0.2–0.5% above the background rate when performed by experienced providers. Your care team will discuss the specifics of the procedure and any potential considerations with you. For individuals who are Rh-negative, receiving [RhoGAM (Anti-D Immunoglobulin)](/tests/rhogam-rhd-antibody) after a CVS procedure is an important step to prevent Rh sensitization.

## What the results mean

The results from a CVS provide definitive chromosomal information. You can typically expect preliminary results, often from FISH or rapid PCR, within 1–3 days. The full karyotype, which offers a complete picture of your baby's chromosomes, usually takes 1–2 weeks. Receiving these results can help you and your care team understand your baby's health and plan for any necessary support or interventions. Should a chromosomal condition be identified, your provider can discuss what this might mean for your pregnancy and what monitoring might be recommended, such as later in pregnancy with a [Biophysical Profile (BPP)](/tests/biophysical-profile) or an [Umbilical Artery Doppler](/tests/umbilical-artery-doppler) to assess fetal well-being.

## Questions worth asking

As you navigate your options, having a clear conversation with your provider can bring confidence. One option might be to ask about your provider's experience with CVS procedures and their specific miscarriage rates. You might also want to discuss what support resources are available should the results indicate a chromosomal difference. Understanding the timeline for both preliminary and full results can also help you prepare. Remember, you get to decide what feels right for you and your family, and asking questions is a powerful part of making informed decisions.