Ultrasonic Measurement of Fetal Abdomen Circumference in the Estimation of Fetal Weight

Abstract

Summary A method of estimating fetal weight by ultrasonic measurement of the fetal abdominal circumference is described. Assessment of birth weight predictions on 140 fetuses who were delivered within 48 hours of this measurement showed that the accuracy of predictions varied with the size of the fetus; at a predicted weight of 1 kg, 95 per cent of birth weights fell within 160 g, while at 2 kg, 3 kg and 4 kg the corresponding values were 290 g, 450 g and 590 g respectively. Expressed as a percentage of the predicted weight, confidence limits remained constant throughout the birth weight range. Extrapolation of these data to routine screening of the obstetric population showed that with a single measurement at 32 weeks menstrual age, 87 per cent of babies below the 5th centile would be detected by this method but that the diagnosis rate would fall to 63 per cent at 38 weeks. The false positive diagnosis rate would remain constant between 32 and 38 weeks at just over 1 per cent.

Estimation of fetal weight by ultrasonic measurement of several fetal growth parameters.

“…When the estimated diameter exceeded 9.0 cm, 96.1% of the neonates weighed more than 2,500 g. This result was similar to Thompson's. Campbell and Wilkin (1975) has reported that AC determined by ultrasonic measurement is useful for detecting fetal growth, and that a single measurement of fetal AC would also appear to be more efficient in diagnosing a small-for-dates fetus than serial cephalometry and has a lower incidence of false positive diagnosis. They also demonstrated that neonatal birth weight was in excess of 2,500 g if an estimated AC was 29.0-32.0 cm.…”

“…Under this section, we have sometimes found the fetal stomach. This method of abdominal circumference measurement is the same as that described by Campbell and Wilkin (1975). The calculation of abdominal circumference was performed in the same way as head and chest circumferences (Fig.…”

Evaluation of Fetal Growth and Fetal Well-Being

“…17,18 Measurements of the abdominal circumference at the level of the fetal liver seems to hold the best accuracy and is currently considered an indicator of intrauterine fetal growth in the second half of pregnancy. 19 The rationale for this measurement is that it corresponds most closely with the size of the fetal liver.…”

“…30,31 The most successful early approach to estimate fetal weight was a simple correlation between abdominal circumference and birth weight. 17 Numerous further attempts have com- tapraid2/zp7-sult/zp7-sult/zp700208/zp72029d08z karkerap Sϭ1 2/11/08 Art: 249 ce: dlw…”

Experimental Results of Phoebe Framework: Optimal Formulas for Estimating Fetus Weight and Age

“…There are many estimate formulas resulted from gestational researches [2][3][4][5][6][7][8][9][10]. Some of them gain high accuracy but they are only appropriate to population, community or ethnic group where such researches are done.…”