Estimation of gestational age from fundal height: a solution for resource poor settings

Abstract

Short Title: Estimation of gestational age from SFH 2 SUMMARY Many women in resource poor settings lack access to reliable gestational age assessment because they do not know their last menstrual period (LMP), there is no ultrasound and methods of newborn gestational age dating are not practiced by birth attendants. A bespoke multiple-measures model was developed to predict the expected date of delivery (EDD) determined by ultrasound. The results are compared with both a linear and a non-linear model. Prospectively collected early ultrasound and serial symphysis-pubis fundal height (SFH) data were used in the models. The data were collected from Karen and Burmese women attending antenatal care on the Thai-Burmese border. The multiple-measures model performed best resulting in a range of accuracy depending on the number of SFH measures recorded per mother (for example 6 SFH measurements resulted in a prediction accuracy of ± 2 weeks). SFH remains the proxy for gestational age in much of the resource poor world. While more accurate measures should be encouraged we demonstrate that a formula that incorporates at least three SFH measures from an individual mother and the slopes between them provides a significant increase in the accuracy of prediction compared with linear and non-linear formulae also using multiple SFH measures