What is the Quadruple Screening Test Turkey?
The quadruple screening test is a non-invasive screening method that measures four different biochemical markers in the mother’s blood during the second trimester of pregnancy to estimate the risk of chromosomal and neural tube defects in the fetus. The purpose of the test is to identify possible high-risk pregnancies due to genetic anomalies such as Down syndrome (Trisomy 21), Edwards syndrome (Trisomy 18) and Neural Tube Defects (NTD) and to direct them to advanced diagnostic methods (amniocentesis, CVS) when necessary.
When is the Quadruple Screening Test Performed?
Quadruple screening test is usually performed between the 15th and 20th weeks of pregnancy; the most ideal time period is between the 16th and 18th weeks. During this period, AFP (alpha-fetoprotein) production of the fetal liver, placental HCG synthesis and other hormone levels are in a balanced reference range to give the most consistent results with statistical algorithms. After the 20th week, the test sensitivity may decrease and the evaluation may lose its reliability; therefore, timely testing increases the diagnostic value.
What Values Are Measured in the Quadruple Screening Test? (AFP, HCG, Estriol, Inhibin-A)
In the quadruple test, four parameters are measured in the maternal blood:
- AFP (Alpha-Fetoprotein): A protein that passes into the blood via the fetal liver and amniotic fluid; elevated in those at increased risk of NTDs and usually low in Down and Edwards syndrome.
- hCG (Beta-Human Chorionic Gonadotropin): Pregnancy hormone secreted from the placenta, increased in pregnancies with Down syndrome and low in Edwards syndrome.
- uE3 (Free Estriol): An estrogen derivative synthesized in fetal and maternal liver, typically low in Down syndrome, may be variable in other anomalies.
- Inhibin-A: A glycoprotein of placental origin; shows increased levels, helping to detect the risk of Down syndrome with high sensitivity.
What Genetic Risks Does the Quadruple Screening Test Identify?
Quadruple screening has high sensitivity, especially in estimating the risk of Trisomy 21 (Down syndrome) and Trisomy 18 (Edwards syndrome). It also evaluates the probability of congenital spinal cord patency through increased AFP for neural tube defects (spina bifida, anencephaly). Secondary risks such as trisomy 13 and rare chromosomal anomalies and the risk of fetal death can also be included in the algorithm; however, the primary focus of the screening test is trisomies 21 and 18 and NTD.
Differences Between Triple and Quadruple Screening Test
Triple screening includes measurements of AFP, hCG, and uE3, but has slightly lower sensitivity than the quadruple screening test with the added parameter inhibin-A. When inhibin-A is added, sensitivity for Down syndrome increases from around 60–65% to around 75–80%. Furthermore, since the quadruple test does not provide more data for NTD, neural tube defect monitoring is based primarily on AFP; the difference between the triple and quadruple tests in terms of NTD monitoring is minimal. In general, the quadruple test is preferred because it more reliably detects the significant increase in the risk of Trisomy 21.
How is the Quadruple Screening Test Performed?
For the test, 5–10 ml of blood is taken from the mother’s forearm and the week compatible with the fetal age is confirmed by ultrasonography. The sample is sent to a reference laboratory and AFP, β-hCG, uE3 and inhibin-A levels are determined quantitatively by chemiluminescence or immunoassay methods. The hormone values obtained are corrected for factors such as maternal age, weight, gestational week, presence of diabetes, multiple pregnancy and entered into the statistical risk calculation software. The result is reported as a ‘risk threshold’ (e.g. 1/250, 1/1000) based on the ‘normal rate for age’ (MoM) for each anomaly.
What Do the Results Mean and How Are They Interpreted?
The MoM value of each parameter is considered ‘normal’ between 0.8–2.0; MoM < 0.5 or > 2.5 raises suspicion of anomaly. The final risk calculation is presented by expressing the calculated ratio for each anomaly as 1/X (e.g. 1/200). Below the threshold (less than 1/250 risk) is classified as ‘low risk’, above the threshold as ‘high risk’. In high-risk pregnancies, genetic counselling, advanced invasive diagnosis (amniocentesis or CVS) and detailed fetal ultrasonography are recommended.
Is the Quadruple Screening Test Reliable?
The quadruple test has a sensitivity of approximately 75–80% for Trisomy 21 and 80–85% for Trisomy 18. AFP-based sensitivity for NTD is 85–90%. The false-positive rate is approximately 5–7%, so it is used only for screening purposes and is not diagnostic. High-risk results must be confirmed by invasive testing for definitive diagnosis.
What to Do If the Test Result is Risky?
Genetic counseling is recommended for pregnancies reported as high risk. Subsequently, fetal chromosome analysis can be performed by invasive methods such as amniocentesis (weeks 15–20) or chorionic villus sampling (CVS, weeks 11–14). Organ anomalies are investigated simultaneously with detailed fetal ultrasound. Psychosocial support and physician monitoring are continued until the results are finalized.
Quadruple Screening Test Prices 2026
As of 2026, the prices of the quadruple screening test vary between ₺2,500 and ₺4,000 depending on the clinic and laboratory infrastructure. This fee covers blood collection, hormone analysis, risk calculation report and weekly verification with ultrasound. Genetic counseling or advanced invasive tests create additional costs; you can contact us for clear pricing information and package options—get a quote from us!
Frequently Asked Questions
Is the quadruple screening test performed on an empty stomach?
There is no specific fasting requirement for the quadruple screen; the mother should continue her normal diet. You may be dehydrated before the blood sample is taken, but carbohydrate or protein intake does not significantly affect hormone levels. However, some centers may recommend avoiding heavy, fatty foods or fasting for several hours before the test, which will reduce the risk of blood clotting and improve sample quality. Providing a quiet rest period of 30–60 minutes before the test will help minimize adrenal stress hormones.
In which week is it done?
The quadruple screen is ideally performed between 16 and 18 weeks of pregnancy, when fetal liver AFP production, placental hCG and inhibin-A secretion, and fetal-maternal estriol levels are most amenable to statistical modeling. It can also be performed between 15 and 20 weeks, but the reliability of MoM calculations decreases after 20 weeks. The risk of false-negative or false-positive results increases in pregnancies tested too early (before 14 weeks) or too late (after 20 weeks).
Does it definitely indicate the risk of Down syndrome?
The quadruple screening test offers a sensitivity of around 75–80% for Down syndrome and works with standardized parameters in a laboratory setting; however, it is not a diagnostic test. A high-risk finding indicates the need for advanced invasive methods (amniocentesis or CVS) for fetal chromosome analysis. A definitive diagnosis is made with the results of these invasive tests. The quadruple test is for “screening” purposes only and identifies cases at risk and reveals the need for more detailed examination of the pregnancy.
Does the quadruple test result indicate gender?
The biochemical markers measured in the quadruple screening test (AFP, hCG, uE3, inhibin-A) do not include gender information and cannot determine fetal gender. Gender determination is only possible with ultrasound imaging of the genital area of the fetus or cellular genetic studies (gender-specific chromosome testing). Therefore, no gender information such as “girl” or “boy” is reported as a result of the quadruple test.
What should be done if the result is risky?
If a value above the risk threshold (e.g. 1/250) is calculated as a result of the quadruple screening, a “high risk” diagnosis is made and the expectant mother is referred to genetic counseling. Here, invasive diagnostic options are evaluated in detail:
- Chorionic villus sampling (CVS): Tissue is taken from the placenta during the 11th–14th weeks of pregnancy and chromosome analysis is performed.
- Amniocentesis: Detailed genetic analysis is performed by cell sampling from the amniotic fluid during the 15th–20th weeks of pregnancy.
At the same time, advanced fetal ultrasonography is used to check for structural anomalies. Additional biochemical screening or non-invasive prenatal testing (NIPT) may be used until a definitive diagnosis is made. Psychosocial support and detailed information are provided throughout the process.