Man & Pregnancy: week 15 & the triple screen

The triple screen test is a maternal blood screening test that looks for three specific substances: AFP, hCG, and Estriol. The triple screen test is performed between the 15th and 20th week of pregnancy.

AFP: alpha-fetoprotein is a protein that is produced by the fetus.

hCG: human chorionic gonadotropin is a hormone produced within the placenta

Estriol: estriol is an estrogen produced by both the fetus and the placenta

It is very important to remember what a screening test is before getting one performed. This will help alleviate some of the anxiety that can accompany test results. Screening tests do not look only at results from the blood test. They compare a number of different factors (including age, ethnicity, results from blood tests, etc...) and then estimate what a person’s chances are of having an abnormality. These tests DO NOT diagnose a problem; they only signal that further testing should be done.

High levels of AFP may suggest that the developing baby has a neural tube defect such as spina bifida or anencephaly. However, the most common reason for elevated AFP levels is inaccurate dating of the pregnancy.

Low levels of AFP and abnormal levels of hCG and estriol may indicate that the developing baby has Trisomy 21( Down syndrome), Trisomy 18 (Edwards Syndrome) or another type of chromosome abnormality.

Abnormal test results warrant additional testing for making a diagnosis. A more conservative approach involves performing a second triple screen followed by a high definition ultrasound. If the testing still maintains abnormal results, a more invasive procedure like amniocentesis may be performed.