The Double Marker test is a biochemical marker test which is prescribed to a pregnant lady as a part of the routine antenatal screening. It is usually done between 11 to 13 weeks of pregnancy. It is usually combined with an Ultrasound test known as the NT (Nuchal translucency) scan. This test is a soft marker test which helps in identifying if the unborn child is likely to develop any sort of chromosomal anomaly or mental disorders.
The double marker test is done with a blood sample. It checks for two markers- Free β-hCG (human chorionic gonadotrophin) and PAPP-A (pregnancy-associated plasma protein A). The NT scan is a uses ultrasound during pregnancy to assess the development of the growing fetus.
The Double marker test requires a venous blood sample taken from a vein in the upper arm of the patient, it is collected in a vacutainer and sent to laboratory for testing. The NT scan is done using an ultrasound machine and a trained radiologist assessing the parameters for the scan.