Antenatal screening includes a series of blood tests which are a diagnostic recommendation through the first and second trimester of pregnancy, to assess health of the carrying woman as well as the unborn child/fetus. These screening tests are typically for risk estimation to determine the chances of the fetus carrying any chromosomal anomaly using mother’s blood.
These tests are prescribed as per risk which includes age of the mother, history, or in case of any suspicion raised by other blood tests. These include the following tests depending upon age of gestation or pregnancy stage.
Popular serum-based screening

- Serum Double Marker Screening
- Triple Marker Screening
- Quadruple Marker Screening
- Benefits of Antenatal Screening test
The Double marker test is a maternal serum based test to assess certain developmental abnormalities like Down’s or Edward’s syndrome in the fetus or unborn child. It is one of the many early screening tests which a pregnant lady is prescribed between 9-13 weeks of pregnancy and is combined with the Ultrasound (USG). The recommendation for this test is done after taking into account the nuchal translucency or fold of the fetus as measured during USG.
Tests covered
- Free Beta HCG
- PAPP-A (Pregnancy-Associated Plasma Protein)
Risk screened for
- Down’s syndrome or trisomy 21
- Edward’s syndrome or trisomy 18
Sample requirement – 3mL serum in barcoded sample collection tube
TAT – 24 – 48 hours provided all the required required documentation has been submitted on time.
The Triple screen antenatal test is recommended in the second trimester, specifically between the 15th – 20th week of pregnancy. As the name suggests, it checks for three markers in the mother’s blood for risk estimation or finding out the chance of the fetus carrying an abnormality.
Factors taken into consideration while risk calculation include;
- Body weight of the mother
- The Last Menstrual Period (LMP) date
- Smoking history
- USG findings
- Number of fetuses
- IVF status
- Donors Date of Birth
Tests covered
- Alpha-Fetoprotein (AFP)
- Human Chorionic Gonadotropin (hCG)
- Estriol
Risk screened for
- Down’s syndrome or trisomy 21
- Edward’s syndrome or trisomy 18
- Neural Tube Defects (NTD)
Sample requirement – 3mL serum in barcoded sample collection tube
TAT – 24 – 48 hours provided all the required required documentation has been submitted on time.
The Quad Marker test is another second trimester screening test recommended between the 15th – 20th week of pregnancy. Though not diagnostic, this test has proven to be extremely beneficial for risk estimation or to determine the chances of the fetus carrying any abnormality depending on presence/absence of associated risk factors.
Tests covered
- Alpha-Fetoprotein (AFP)
- Human Chorionic Gonadotropin (hCG)
- Unconjugated estriol (uE3)
- Inhibin A
Risk screened for
- Down’s syndrome or trisomy 21
- Edward’s syndrome or trisomy 18
- Neural Tube Defect (NTD)
Sample requirement – 3mL serum in barcoded sample collection tube
TAT – 24 – 48 hours provided all the required required documentation has been submitted on time.
- Early screening for chromosomal disorders
- Aids in determining the true need for further invasive tests
- Easy sample collection with no special expertise required
- Tests feasible in both first and second trimester, so even if one is skipped, the other one can be availed
- The Quad Marker test has been shown to predict ~ 75% – 80% of open neural tube defects
- Reduces pregnancy-related complications to a great extent by giving time for charting clinically-safe remedial measures