When DueDateCalc starts you will be presented immediately with the calculator ready to calculate EDC and EGA from the patient’s LMP.   Simply spin out the patient’s LMP and you will see the Estimated Date of Confinement (also known as EDD) presented in full format, inclusive of day of the week.  There is rough data entry checking in the sense that if your entered date is sufficiently distant, it will likely result in an an EGA which is <0 weeks or >44 weeks which will show up in bright red to alert you.

This process for obtaining EDC/EGA is very similar for the other key data sources:  for calculations based on Conception Date (CD), press the CD on the selector bar.  EDC is calculated as 38 weeks out from conception date.  This is useful in cases where there has been in-vitro or other assisted reproduction and the date is known.  Or, in certain cases where your patient’s cycle length is considerably outside 28 days or she is fairly certain of conception date, using CD would be appropriate.  For calculations relative to the Estimated Date of Confinement, entering simply the EDC (if it is all that is known) will allow you to see the EGA.   For calculations from Ultrasound (US) data, the process is slightly modified in that there is also a need to enter the Gestational Age at the time of the Ultrasound.    In order to enter the GA of the ultrasound, press “Change Gestational Age” on the  selector bar that appears above the date methods. Simply spin-out the weeks and days of the Ultrasound Gestational Age (see below, right).