Serial biparietal diameter and femur length measurements in twin gestations

Biparietal diameter and femur length measurements from 60 twin pairs were used to construct fetal twin growth tables. From 18 through 38 weeks of gestation the biparietal diameter measurements were accurate within +/- 1.9 weeks, and the femur length within +/- 2.1 weeks in the prediction of gestational age. Since this data was obtained from a predominantly white middle class population it may prove more reliable in similar groups for predicting the adequacy of fetal growth and gestational age than prior data obtained using indigent populations.