Good to knowOne result rarely tells the whole story. Your provider looks at your results together with your symptoms, exam, and other tests.
What the test is
CVS is done at 10 to 13 weeks; amniocentesis usually at 15 to 20 weeks. They're diagnostic, unlike screening tests.
Why it's done
- A positive screening result
- Family history or carrier status for a genetic condition
- An ultrasound finding
Getting ready and what happens
- Meet with a genetic counselor. Ask whether to come with a full bladder.
How the test is done
- A thin needle (or catheter for CVS) collects a small sample guided by ultrasound.
What the results mean
Results
Give a near-certain answer about the conditions tested.
When a result needs quick action
Call your provider todayFever, heavy bleeding, fluid leaking, or strong cramps after the procedure
Questions to ask your provider
- What do my results mean for me?
- Do I need to repeat this test or have other tests?
Risks
A small risk of miscarriage (well under 1% in experienced centers), cramping, or leaking fluid.
Related conditions
Related tests
Sources
Last updated 2026-11-13.