Also known as Triple Marker Pregnancy Test (Graph), Maternal Screening Test
Understanding the Triple Test
What It Is:
The Triple Test, also known as the Triple Marker Test or Triple Screen, is a prenatal screening test performed during the second trimester of pregnancy. It measures the levels of three substances in the mother's blood to assess the risk of chromosomal abnormalities and neural tube defects in the developing baby.
The three substances measured are:
Alpha-fetoprotein (AFP): A protein produced by the fetus's liver.
Human chorionic gonadotropin (hCG): A hormone produced by the placenta.
Unconjugated estriol (uE3): An estrogen produced by both the fetus and the placenta.
Why It's Done:
Assessing Risk:
The test evaluates the risk of the baby having certain genetic disorders and birth defects, such as:
Down syndrome (Trisomy 21): A chromosomal disorder causing intellectual disability and developmental delays.
Trisomy 18 (Edwards syndrome): A chromosomal disorder that is often fatal and causes severe developmental delays.
Neural tube defects (NTDs): Birth defects affecting the brain and spinal cord, such as spina bifida.
How the Test Works:
Procedure:
The Triple Test is typically performed between the 15th and 20th weeks of pregnancy, with the optimal window being 16–18 weeks.
A healthcare professional will take a blood sample from a vein in the mother's arm using a small needle.
The blood sample is collected into a test tube or vial and sent to a laboratory for analysis.
The levels of AFP, hCG, and uE3 are measured and compared to expected norms based on the mother's age, weight, ethnicity, and gestational age.
Understanding the Results:
Normal Range:
The levels of the three substances are compared to normal ranges for the specific stage of pregnancy.
The results are combined with other factors to assess the risk of genetic disorders and birth defects.
Abnormal Findings:
Abnormal levels of the substances may indicate an increased risk of genetic disorders or birth defects.
Further diagnostic tests, such as amniocentesis or chorionic villus sampling (CVS), may be recommended to confirm the diagnosis.
Why Your Doctor Might Order This Test:
Risk Factors:
The test is recommended for all pregnant women, especially those with risk factors such as:
Age of 35 or older when the baby is due.
Family history of genetic disorders.
Previous child with a birth defect.
Diagnosis of Type 1 diabetes prior to pregnancy.
Viral infection during pregnancy.
Exposure to high levels of radiation.
Usage of harmful medications or drugs during pregnancy.
Symptoms That Might Prompt This Test:
The Triple Test is a routine screening test and is not typically prompted by specific symptoms. It is part of standard prenatal care to assess the risk of genetic disorders and birth defects.
Lifestyle and Management:
Depending on the results, your healthcare provider might recommend further tests, treatments, or lifestyle changes to manage the pregnancy effectively.
Regular monitoring and follow-up are essential for successful pregnancy management.