The California Prenatal Screening Program was introduced in 1986 by the California Department of Public Health. The Program was previously known as the "Expanded AFP Program." There are three variations of screening tests currently offered to pregnant women in order to identify individuals who are at increased risk for carrying a fetus with a specific birth defect.

  • Quad Marker Screening - One blood specimen at 15 weeks - 20 weeks of pregnancy (second trimester test).
  • Serum Integrated Screening - Combines a first trimester blood test (10 weeks - 13 weeks 6 days) with a second trimester blood test (15 weeks - 20 weeks).
  • Sequential Integrated Screening - Combines first and second trimester blood test results with Nuchal Translucency (NT) ultrasound results. This type of ultrasound is done by clinicians with special training. It measures the back of the fetus' neck. This measurement helps screen for Down Syndrome. (Note: the Screening Program does not pay for NT ultrasounds) Patients with first trimester blood specimens and NT will get a preliminary risk assessment for chromosomal abnormalities in the first trimester. This preliminary risk will be revised when the second trimester blood specimen is received.


The Prenatal Screening Program provides pregnant women with a risk assessment for open neural tube defects (NTD), abdominal wall defects (AWD), Down syndrome (trisomy 21), Trisomy 18 and SLOS (Smith-Lemli-Opitz Syndrome) through one or two blood tests. Because the screening doesn't diagnosis fetal birth defects, the Program provides women who are at high risk, based on the screening test results, free follow-up services at State-approved Prenatal Diagnosis Centers (PDCs) (PDF). Services offered at these Centers may include genetic counseling, ultrasound, NIPT, CVS, and amniocentesis.  Participation in the screening testing and follow-up services is voluntary. The cost of the testing through the Prenatal Screening Program is $222.

UC Davis Department of Obstetrics and Gynecology has a contract from the Department of Public Health-GDSP (Genetic Disease Screening Program) to provide case management and follow-up services for women whose results show an increased risk.

For more information in English, read the Prenatal Screening Patient Booklet (PDF).

Click here for additional information and booklets in other languages.

Prenatal Genetic Screening Patient Education