Quad marker screening (measurement, proportions)

My husband and I are expecting our second child in September, and just like all parents, our main concern is the health of the baby. We chose to have a quad marker screening, which requires amazingly precise mathematical measurements and calculations. The screening test measures four substances in a blood sample. The levels are compared to normal amounts for the current gestation period. If the due date is calculated incorrectly, or any of the substances are measured incorrectly, the results will be inaccurate. For more information on the Quad Marker test, click here.