Quadruple Marker Test

Test Description

The Quadruple Marker Test, also known as the Quad Screen or Quad Test, is a prenatal blood screening performed during the second trimester of pregnancy, typically between the 15th and 20th weeks. This test measures the levels of four specific substances in a pregnant woman’s blood.

1. Alpha-fetoprotein (AFP)

• Description:  AFP is a protein produced primarily by the fetal liver and yolk sac during pregnancy. It serves as a carrier protein, similar to albumin, transporting substances such as fatty acids.
• Clinical Significance: Elevated levels of AFP in maternal serum can indicate neural tube defects (e.g., spina bifida) or abdominal wall defects (e.g., omphalocele). Conversely, low levels may suggest an increased risk for Down syndrome or other chromosomal abnormalities.
• Normal Range: AFP levels typically rise during pregnancy, peaking between 15 and 20 weeks, with normal values generally ranging from 10 to 150 ng/mL during this period.

2. Human Chorionic Gonadotropin (hCG)

• Description:  hCG is a hormone produced by the placenta shortly after implantation. It is crucial for maintaining pregnancy and stimulating the production of progesterone.
• Clinical Significance: Elevated hCG levels can indicate multiple pregnancies or certain types of tumors, while low levels may suggest potential complications such as ectopic pregnancy or miscarriage.
• Normal Range: The expected range varies widely during early pregnancy but typically decreases after the first trimester.

3. Unconjugated Estriol (uE3)

• Description:  uE3 is an estrogen produced by both the placenta and the fetus. It plays a role in preparing the body for childbirth.
• Clinical Significance: Low levels of uE3 can be associated with an increased risk of Down syndrome and other chromosomal abnormalities. It helps in assessing fetal well-being and placental function.
• Normal Range: Levels of uE3 increase as pregnancy progresses, particularly in the second trimester.

4. Inhibin A

• Description:  Inhibin A is a hormone secreted by the placenta that regulates follicle-stimulating hormone (FSH) levels.
• Clinical Significance: Elevated Inhibin A levels are often linked to an increased risk of Down syndrome. It provides additional information when interpreting results from other markers.
• Normal Range: The normal range for Inhibin A varies but is generally assessed alongside other markers for comprehensive risk evaluation

 

The primary purpose of this test is to assess the risk of certain birth defects and chromosomal abnormalities, including Down syndrome (Trisomy 21), Trisomy 18 (Edwards syndrome), and neural tube defects such as spina bifida.

Indications of the Test

The Quadruple Marker Test is recommended for all pregnant women, particularly those with risk factors such as:

• Age 35 or older at the time of delivery.
• Family history of birth defects.
• Previous child with a birth defect.
• Pre-existing medical conditions like Type 1 diabetes.
• Exposure to harmful substances or infections during pregnancy.

Patient Preparation/Instructions

There are no specific preparations required before undergoing the Quadruple Marker Test. Patients can eat and drink normally prior to the test. However, it is advisable to avoid alcohol and smoking to ensure accurate results. The blood sample collection is a simple procedure that takes approximately 5-10 minutes.

Typical Reference Values

Normal results from the Quadruple Marker Test indicate a low risk for major birth defects.

While specific reference values can vary based on laboratory standards and individual factors such as gestational age and maternal characteristics, normal results generally suggest that over 98% of pregnancies will proceed without significant complications.

Turnaround Time

Results from the Quadruple Marker Test are typically available within 4 to 7 days after sample collection, depending on the laboratory processing time.

Order This Test

To order the Quadruple Marker Test, please click the ‘Order Test’ button and add it to your cart. This test provides valuable information about your pregnancy and is an essential part of prenatal care.