Estimated fetal weight: Applicability to small- and large-for-gestational-age fetus

✍ Scribed by Joseph M. Miller Jr.; Grace A. Kissling; Haywood L. Brown; Harvey A. Gabert

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 253 KB
• Volume: 16
• Category: Article
• ISSN: 0091-2751
• DOI: 10.1002/jcu.1870160205

✦ Synopsis

Ultrasonic formulas using femur length and abdominal circumference with or without biparital diameter were found to be highly accurate in predicting the weight of normal-sized term infants. The small-for-gestational age fetus, however, was overestimated and the large-for-gestational-age fetus was underestimated. The fetal weight formulas tested that were appropriate for the entire study group were not applicable to those fetuses having altered growth. Indexing Words: Ultrasound * Estimated fetal weight Numerous ultrasonic formulas exist for the estimation of fetal weight. Most are a polynomial or exponential function relating biparietal diameter (BPD) and/or femur length (FL) with abdominal circumference (AC) to estimated fetal weight (EFW).lP4 These have been applied in clinical settings and experience has confirmed their general usefulness. Difficulty has been encountered in two subgroups: the small-for-gestational-age fetus (SGA)435 and the unusually large Many studies have analyzed a relatively small number of patients, often less than 150, and have had fewer patients in the subgroup categories.

Using a large series of term patients who underwent sonography, we assessed the accuracy of EFW formulas using BPD and/or FL with AC and its subsequent interpretation, which was done in a manner similar to that of the authors who devised the formulas. 1-3 The hypothesis tested was that the EFW formula accurately predicts weight of SGA and large-for-gestationalage (LGA) fetuses.