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Prenatal Screening program

Pregnant Individual on a Bench

Genetic Conditions and Birth Defects Screened for 

Most babies are born without any type of genetic condition or birth defect. But with all pregnancies, there is a 3 to 4 out of 100 chance for this to happen.

The California Prenatal Screening (PNS) Program screens for the genetic conditions and birth defects described on this page. Please consult with your prenatal care provider or genetic counselor on whether to get prenatal screening. You decide whether to get prenatal screening or not. 

If a screening result indicates an increased chance​ of a specific genetic condition or birth defect​, diagnostic testing is needed to tell whether the fetus has that condition or defect.

If diagnostic tests show that your baby has a genetic condition or birth defect, a prenatal care provider or genetic counselor at a state-approved Prenatal Diagnosis Center (PDF) will give you information. They will discuss the genetic condition or birth defect and options for your pregnancy.

Genetic Conditions

  • Down syndrome (trisomy 21)
  • Trisomy 18
  • Trisomy 13

Starting April 1, 2024, the CA PNS Program will add sex chromosome aneuploidies (SCAs) – also referred to as X and Y chromosome variations – to the state cell-free DNA screening panel.

  • ​Turner syndrome
  • Klinefelter syndrome
  • Trisomy X
  • XYY​

Birth Defects

  • Neural Tube Defects (they affect the brain, spine, or spinal cord)

Below is more information on the genetic conditions and birth defects screened for by the PNS Program.

Frequently Asked Questions

What Conditions are Commonly Tested for During Pregnancy? Video:


Transcript (PDF)
What Conditions Are Commonly Tested for During Pregnancy? Genetic Support Foundation/Washington Department of Health, 4.32 minutes. Please note that this video covers structural defects and sex chromosome changes that the PNS Program does not screen for. 

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