Comparison of fundal height measurement and sonographically measured fetal abdominal circumference in the prediction of high and low birth weight at term

Abstract

To compare the diagnostic value of fundal height and sonographically measured fetal abdominal circumference in the prediction of high and low birth weight in routine practice between 37 and 41 weeks' gestation. Data were obtained from a multicenter study of 19 415 women in France and Belgium. In this study we included 7138 low-risk women from that population who underwent fundal height measurements no more than 8 days before delivery (Population A). We also included another 1689 women with both fundal height measurements and fetal ultrasound measurements obtained no more than 8 days before delivery (Population B). Population A was used to calculate the parameters of equations for estimating fetal weight according to fundal height alone (EFW(FH)) or fundal height in combination with other clinical indicators (EFW(FH+)). The ultrasound fetal weight estimation was based on fetal abdominal circumference (EFW(AC)) using Campbell and Wilkins' equation. The correlation between the estimated fetal weight calculated using each of the formulae and the birth weight was then evaluated in Population B, and the diagnostic value of each of the methods for predicting birth weight <or=2500 g or >or=4000 g was also compared. EFW(AC) was better correlated with birth weight than was either EFW(FH) or EFW(FH+). With specificity set at 95%, the sensitivity of EFW(AC) in screening for neonates weighing <or=2500 g was significantly higher than that of EFW(FH) (50.7% vs. 41.2%, P < 0.05) or EFW(FH+) (50.7% vs. 40.4%, P < 0.05). Similarly, its sensitivity for predicting a birth weight of >or=4000 g was significantly higher than that of EFW(FH) (54.0% vs. 37.1%, P < 0.05) or EFW(FH+) (54.0% vs. 45.1%, P < 0.05). Sonographic measurement of fetal abdominal circumference predicts high and low birth weight better than does clinical examination based on fundal height in routine practice between 37 and 41 weeks' gestation.