ESTAGEST: an obstetrical application program in BASIC for the computation of estimated date of confinement

The establishment of the estimated date of confinement (EDC) is an essential element in the care of pregnant women. Unfortunately, accurate information on the last menstrual period, the usual determinant of EDC, is not always available, or clinical estimations of gestational age may be discrepant. Prior studies have demonstrated that an average of several clinical examinations can provide a useful prediction of EDC. We have developed a simple BASIC computer program which allows the clinician to input up to 20 clinical examinations and determines the average EDC based on the clinical dates. The program displays the EDC for each individual examination, which provides an indication of the dispersion, or discrepancy, among the examinations. Average intervals to delivery date from the occurrence of clinical estimators of gestation are based on observed data at our institution and can be easily modified to fit local norms.