Penta Maternal Screen Panel, Serum**

The First Trimester Test-VI, also known as the Penta Screen, is a screening test that is usually performed between 11 to 13.6 weeks of pregnancy. The test is a combination of several different markers that are measured in the mother's blood to assess the risk of chromosomal abnormalities and other fetal disorders.

Free beta human chorionic gonadotropin (β-hCG) is a hormone that is produced by the placenta and is measured in the mother's blood. Abnormal levels of β-hCG can indicate an increased risk of chromosomal abnormalities such as Down syndrome. Pregnancy-associated plasma protein A (PAPP-A) is a protein that is produced by the placenta and is measured in the mother's blood. Low levels of PAPP-A can indicate an increased risk of chromosomal abnormalities. Alpha-fetoprotein (AFP) is a protein that is produced by the fetal liver and is measured in the mother's blood. Abnormal levels of AFP can indicate an increased risk of neural tube defects and other fetal disorders. Inhibin A is a hormone that is produced by the placenta and is measured in the mother's blood. Abnormal levels of inhibin A can indicate an increased risk of chromosomal abnormalities. Placental growth factor (PLGF) is a protein that is produced by the placenta and is measured in the mother's blood. Abnormal levels of PLGF can indicate an increased risk of preeclampsia, a serious pregnancy complication. Nuchal translucency (NT) is a measurement of the thickness of a space at the back of the fetal neck, which is measured by ultrasound. The abnormal thickness of the NT can indicate an increased risk of chromosomal abnormalities and other fetal disorders.

The results of the Penta Screen are combined with the mother's age and other factors to calculate a risk score for chromosomal abnormalities such as Down syndrome, trisomy 18, and trisomy 13.