How to Interpret a Quad Screen Test

The Quad Screen Test is administered in the second trimester of pregnancy. It measures four hormones: alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), unconjugated estriol (uE3) and inhibin A. Your age, weight, ethnicity, family history and baby's gestational age are other factors measured. The Quad Screen Test examines the possibility of fetal developmental or chromosomal abnormalities, including Down syndrome, spina bifida and Edwards syndrome.

Instructions

• 1

  Take a blood test. The results will be sent to the lab for evaluation. Ask your doctor to give you the lab's normal spectrum of results.

• 2

  Check for Down syndrome. AFP and uE3 will read below the norm. Inhibin A and hCG will be high. The Quad Screen Test can detect 80 percent of affected fetuses.

• 3

  Look for Edwards syndrome. Unconjugated estriol and hCG levels will be low. AFB will be abnormal, but it can read either higher or lower.

• 4

  Pursue further testing. The Quad Screen Test is not definitive. It shows that there is an increased possibility for genetic abnormalities. A positive test result calls for further investigation.

• 5

  Take a fetal ultrasound. Besides giving the fetus's age, the test closely examines the brain, spinal cord, kidneys and heart. Repeat the Quad Screen Test with the updated ultrasound data. Amniocentesis is another possible follow-up test.