The user selects the calculator of interest. In this example, the calculator from data published by DeVore is selected.

Of the three choices, the calculator for the 91% detection of Down syndrome is selected.

The user enters the patients name, Date of examination, maternal age, and gestational age. Step 1 involves entering the risk for Down syndrome. In this example the risk is 1 in 300. Therefore, 300 is entered.

Step 2. The user selects the ENTER button.

If the user is unsure of how to use this calculator they can click the Calculator Instructions button to review how to use the program.

After reviewing the instructions the user selects the abnormal finding, tricuspid regurgitation (Step 3).

To compute the risk, the user clicks the COMPUTE button (Step 4). The risk is then computed.

By clicking the PRINT button, this screen appears. The user can enter comments and then print the report.