Standards for ultrasound fetal growth velocity

Objective An ultrasound study to establish the nature and limits of fetal growth in a low risk population from 22 weeks of gestation until term.

Design Prospective, longitudinal ultrasound study of 274 low risk pregnancies involving organised scanning schedules with all measurements performed by one observer using the same equipment.

Results Growth velocity charts have been created for a number of ultrasound parameters including estimated fetal weight, by applying appropriate statistical methods to the serial data. The rates of growth of the biparietal diameter, femur length, abdominal area and estimated weight each have characteristic patterns demonstrating maximal growth rates at different gestations.

Conclusions Appropriately derived and calculated ultrasound fetal growth velocity standards have been established. These data are suitable for the evaluation of ultrasonically estimated fetal growth rates in the prediction of adverse perinatal outcome and the further investigation of the role of the intrauterine environment in the origin of adult disease.