Abstract
In 178 pregnant patients there was either inability to recall the date of the last menstrual period, or there was a clinical discrepancy between uterine growth and calculated duration of pregnancy. The author attempts to forecast the expected date of delivery by ultrasonic measurement of fetal biparietal diameter. When the 40th week was considered as a mean value, 96% of the patients delivered between the 37th and the 43rd week in the control group versus 84% in the study group. If the 41st week is taken as the mean value the corresponding figures are 94% and 91% respectively.