Triple Marker, Serum

Triple marker maternal screening is done in the second trimester of pregnancy to evaluate the risk of chromosome disorders (Down syndrome, Edwards syndrome, spina bifida or anencephaly) in the fetus. The tests are combined into a triple or quadruple screening. The levels of AFP, hCG, unconjugated estriol, and sometimes inhibin A along with maternal age, weight, race, and diabetic status, etc are used to determine a numerical risk for abnormalities in the fetus. Triple marker maternal screening is done along with first trimester screen and cell-free fetal DNA testing to detect fetal abnormalities. Triple marker maternal screening is routine screening test but it is highly recommended for women who have a family history of birth defects, age>35 years, diabetic on insulin, viral infection or exposed to radiation during pregnancy. However Triple marker maternal screening tests is not diagnostic of any disease but aids in further testing. Triple marker test includes Estriol (estrogen produced by fetus and the placenta), hCG (hormone produced by placenta) and AFP (a protein that is produced by fetus).

1. What is Down syndrome?

Down syndrome (trisomy 21) causes mental retardation and developmental problems and can be associated with congenital heart defects, respiratory and hearing problems, leukemia, and thyroid disorders. Down syndrome and other chromosomal abnormalities increase with the increased age of the mother.

2. What is Edwards syndrome?

Edwards syndrome (trisomy 18) is associated with multiple fetal abnormalities and is usually fatal. The frequency of this abnormality is much less than Down syndrome, and as with Down syndrome, its risk increases with the increasing maternal age.

3. I am pregnant will I have both first and second trimester screening performed?

Yes, first trimester screening for chromosome abnormalities includes tests for PAPP-A, hCG and nuchal translucency ultrasound. Second trimester maternal serum screening (triple or quad screen) includes tests for inhibin A and AFP additionally.