

The second-trimester prenatal screening test includes several blood tests, which also known as multiple markers. Because of these markers, you can get information about potential risks of certain genetic conditions, or birth defects. This screening is usually done by taking a blood sample between the 15th-20th weeks of pregnancy.
AFP Screening
This blood test measures the level of alpha-fetoprotein in blood during pregnancy. This protein normally made by the fetal liver. The abnormal level of AFP means:
• Down syndrome
• Twins-more than one fetus is making protein
• You may have Open Neural Tube Defects (ONTD) such as Spina Bifida
• Problems in the abdominal wall of a fetus Estriol
This is a hormone, measured in maternal blood or urine, and is used to determine fetal health.
Inhibin
This hormone is also made by the placenta like Estriol. The Inhibin A test is done to measure the amount of this particular hormone in blood during pregnancy to see if the baby may have Down syndrome disorder.
Remember that these multiple markers screening is not diagnostic, so this screening test is not 100 percent accurate. When you take both first and second-trimester screening tests, the ability of tests to detect any disorder increases as compares to when using just one screening test independently.
Prenatal DNA Test Atlanta professionals can help you in regarding various types of screening tests, you can also take assistance for choosing a suitable prenatal screening test for particular chromosomal and genetic abnormalities.