Ultrasonic estimation of gestational age and fetal weight

Ultrasonic fast-scanning analysis was carried out during the 2nd and 3rd trimesters of pregnancy. In 1690 cases biparietal diameter, in 784 chest transverse diameter measurements were done and suitable growth charts constructed for the estimation of gestational time. Both the biparietal and chest transverse diameter values were taken into consideration in 582 cases and the results analysed by mathematical methods. A method has been worked out for the estimation of fetal weight with an absolute standard error of 261 g. On the basis of comparative studies it is suggested that obstetrical teams working with ultrasonic devices should establish their own set of parameters and methods.