The double marker test is suggested for a pregnant women above 35 years of age who carry a high risk of delivering a child with Down's syndrome. However, it is recommended even for younger age women. This test helps in the detection of pre-birth conditions of the fetus and is usually done after 8 weeks of pregnancy up to 14 weeks. This test detects any kind of chromosomal abnormalities that might occur after the conception occurs. Doctor may recommend ultra sound test first, based on the results of ultra-sound test he may suggest for this Double Market test. This test is usually suggested by doctors to pregnant women above 35 years, a family history of birth defects, previous child born with birth defects, History of insulin-dependent (type 1) diabetes.