Double / Quadruple Marker test
Nowadays this can be replaced by the alternative option of NIPT/NIPS test in combination with a USG scan.
a) First trimester dual marker test
Specifically, this test screens for blood levels of both free beta-human chorionic gonadotrophin (beta-hCG) and pregnancy-associated plasma protein A (PAPP-A) and is done on the blood at 11 to 14 weeks For the most accurate results, the double marker test (blood test) and NT scan (ultrasound) are used together in the first trimester screening. The information gathered from both tests is what gives the result of a low-, moderate-, or high-risk of abnormalities.
b) Second trimester Quadraple (Quad test) marker test
The quad screen — also known as the quadruple marker test, the second trimester screen or simply the quad test — is a prenatal test that measures levels of four substances in pregnant women's blood:
1. Alpha-fetoprotein (AFP), a protein made by the developing baby.
2. Human chorionic gonadotropin (HCG), a hormone made by the placenta.
3. Estriol, a hormone made by the placenta and the baby's liver.
4. Inhibin A, another hormone made by the placenta.
Ideally, the quad screen is done between weeks 15 and 18 of pregnancy — during the second trimester. However, the procedure can be done up to week 22. The quad screen is used to evaluate whether your pregnancy has an increased chance of being affected with certain conditions, such as Down syndrome or neural tube defects. If your risk is low, the quad screen can offer reassurance that there is a decreased chance for Down syndrome, trisomy 18, neural tube defects and abdominal wall defects.
If the quad screen indicates an increased chance of one of these conditions, you might consider additional screening or testing The quad screen has traditionally been one of the most commonly used screenings in the second trimester.
Was generally used if prenatal care began during the second trimester or if first trimester screening, which involves a blood test and an ultrasound exam, wasn't available. Before the screening, the patient should think about what the results mean to her. Consider whether the screening will be worth any anxiety it might cause, or whether the patient will be able to handle her pregnancy differently depending on the results. One might also consider what level of risk would be enough for you to choose a more invasive follow-up test.
Nowadays this can be replaced by the alternative option of NIPT/NIPS test in combination wuth an USG anamoly scan.
