Main content

    Learning About Your Health

    Integrated Screening for Down Syndrome

    Printer-friendly PDF of Integrated ScreeningOpens new window (108KB)
    (Download a free copy of Adobe Acrobat ReaderOpens new window)

    What is an Integrated Screening Test?

    Integrated screening is a test for Down syndrome available to pregnant women of all ages. About 9 out of 10 cases of Down syndrome are found (detected) by integrated screening (about a 92% detection rate).

    Compared with other screening tests, such as the California Expanded AFP Program, integrated screening offers a high detection rate for Down syndrome and has a low false-positive rate.
    Note: A false-positive result is one that shows a high risk for Down syndrome in a pregnancy that does not have this syndrome.

    Back to top

    Your Integrated Screening Visits

    Integrated screening is done at the Prenatal Diagnosis Center in two stages:

    1. The first stage is done between 10 weeks, 4 days and 13 weeks, 6 days of your pregnancy.

      • First, a genetic counselor explains the test and reviews your medical history.

      • Next, a special ultrasound confirms the dates of your pregnancy, and measures your baby's "Nuchal Translucency" (NT). Nuchal Translucency is a Down syndrome test that looks at the fold of skin at the back of your baby's neck.

      • Then, a nurse takes a sample of your blood to measure the amount of pregnancy associated plasma protein-A (PAPP-A) in your blood.

      • Finally, we tell you when to return for your second blood test.
    2. The second stage is done at 15 – 16 weeks of pregnancy, but no later than 21 weeks.
      • A nurse takes a second blood sample to measure the amount of four (4) proteins in your blood:
        1. Alpha-fetoprotein (AFP)

        2. Human chorionic gonadrotropin (hCG)

        3. Unconjugated estriol (uE3)

        4. Inhibin A (IhA)

    Back to top

    Test Results

    The integrated screening results are usually ready one (1) week after the second stage (2nd blood test). You also get screening results for other disorders including Trisomy 18 and open neural tube defects (Spina Bifida).

    A genetic counselor from the Prenatal Diagnosis Center contacts you by phone with your results and to schedule any follow-up, if needed. Your obstetrician also receives a copy of your integrated screening results.

    Back to top

    How Is Integrated Screening Different From California's Expanded AFP Screening?

    The state of California offers Expanded AFP screening for all pregnant women. This test uses information only from the second trimester (4 – 6 months).

    Integrated screening uses information from the first and second trimesters of pregnancy. This test has a higher detection rate for Down syndrome (92% for integrated screening versus 60% for California Expanded AFP screening), and a lower false positive rate.(Wald et al)

    Back to top

    What Does a Positive Result for Down Syndrome Mean?

    • A "screen positive" result means that your baby has a higher risk for Down syndrome. If your test result is positive, you will be offered an amniocentesis (a test that examines a baby's chromosomes (genetic material).

    • Your integrated screening result is screen positive if the risk for Down syndrome is one in 270 or higher.

    • Five out of every 100 women who take the test receive a positive result and are considered "screen positive." Most women with screen positive results will not have a baby with Down syndrome.

    Back to top

    What Does a Negative Result for Down Syndrome Mean?

    A "screen negative" result means that the risk for Down syndrome on integrated screening is lower than 1 in 270.
    Note: A screen negative result cannot completely rule out the possibility of having a baby with Down syndrome.

    Back to top

    What if I Do Not Have Blood Drawn for the Second Stage?

    If you do not have the second blood test before 21 weeks of pregnancy, we cannot give you an integrated screening result. You are given a result based only on the first stage.
    Note: This limited result is less accurate than integrated screening.

    Back to top

    What if my Ultrasound Shows I am too Late for the First Stage of the Test?

    If your ultrasound shows that you are too late for the first stage of the test, you will not be able to have integrated screening. However, you may choose to have a different screening test, like the California Expanded AFP.

    Back to top

    More Ways to Learn

    Call (415) 600-6400 to speak with a Genetic Counselor at the Prenatal Diagnosis Center.

    Back to top

    Frequently Asked Questions

    Question: What is integrated screening?
    Answer: Integrated screening is a test for Down syndrome. Compared with other screening tests, integrated screening offers a high detection rate for Down syndrome and keeps the false-positive rate low.

    Question: When do I get the test results?
    Answer: A genetic counselor contacts you within one week after your second blood test.

    Question: What happens if I screen positive?
    Answer: A genetic counselor helps you schedule a follow-up, if needed.

    Note: This handout is also available in Chinese and Spanish.

    Wald, NJ et al., First and second trimester antenatal screening for Down's Syndrome: The Results of the Serum, Urine, and Ultrasound Screening Study (SURUSS). Health Technology Assess 2003;7(11).

    Produced by the Center for Patient and Community Education in association with the Women and Children's Center at California Pacific Medical Center. Date: 2/07

    Funded by: A generous donation from the Mr. and Mrs. Arthur A. Ciocca Foundation.

    Note: This information is not meant to replace any information or personal medical advice which you get directly from your doctor(s). If you have any questions about this information, such as the risks or benefits of the treatment listed, please ask your doctor(s).

    Back to top