GESTATIONAL-AGE ASSESSMENT .1. ANALYSIS OF INDIVIDUAL CLINICAL OBSERVATIONS

Abstract

Accurate assessment of the estimated confinement date is a cornerstone of obstetric care. Traditionally this date was predicted from historical and clinical examinations; there were few studies of the accuracy of such predictions. Multiple estimators of gestational age were examined in 418 patients who were delivered of infants weighing .gtoreq. 3000 g, following spontaneous labor onset. Mean intervals from an event to delivery were calculated for last menstrual period (284.2 days), quickening (156.3 days), 1st audible fetal heart tones (136.2 days), uterine fundus at the umbilicus (140.8 days) and measurements of the fundal height. The variability in each of these estimators was examined and compared. The last menstrual period, if known with certainty, is the most accurate estimator, followed by the uterus at the umbilicus, 1st heart fetal heard tones, fundal height and quickening.