A normal result means there are no signs of any genetic defects. However the test could miss some genetic defects.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
An abnormal result may be a sign of more than 200 disorders, including:
Simpson JL. Otano L. Prenatal Genetic Diagnosis. In: Gabbe SG, Niebyl JR, Simpson JL. Obstetrics - Normal and Problem Pregnancies. 5th ed. New York, NY: Churchill Livingstone; 2007: Chap. 7.