Assessment of the Accuracy of Multiple Sonographic Fetal Weight Estimation Formulas: A 10‐Year Experience From a Single Center. (1st May 2013)

• Record Type: Journal Article
• Authors: Barel, Oshri; Vaknin, Zvi; Tovbin, Josef; Herman, Arie; Maymon, Ron
• Is Part Of: Journal of ultrasound in medicine. Volume 32:Number 5(2013)
• Page Start: 815
• Page End: 823
• Publication Date: 2013-05-01
• Subjects: accuracy -- estimation -- fetal weight -- models -- sonography; Ultrasonics in medicine -- Periodicals; Ultrasonics; Ultrasonography; Ultrasonics in medicine; Electronic journals; Periodicals; Periodicals; 616.07543
• DOI: 10.7863/jum.2013.32.5.815
• Languages: English
• ISSNs: 0278-4297

Abstract

Abstract : Objectives: The primary aim of this study was to compare the accuracy of sonographic fetal weight estimation models. The secondary aim was to define the most accurate time (4–7 or 3 days before delivery) for evaluating fetal weight. Methods: In this retrospective cohort study, a total of 12, 798 sonographic fetal weight estimations were analyzed, of which 9459 were performed within 3 days of delivery and 3339 within 4 to 7 days. The cohort included all singleton pregnancies recorded at a single medical center from January 2000 to December 2010, with 24 weeks' gestation minimum. Predicted birth weights were calculated according to 23 sonographic fetal weight estimation models; in total, 294, 354 sonographic weight estimations were evaluated and compared to the actual birth weights. Results: The accuracy of the models in predicting birth weight differed considerably. The most accurate models used 3 or more fetal measurements followed by models using abdominal circumference only. The models developed by Sabbagha et al ( Am J Obstet Gynecol 1989; 160:854–862) proved most accurate, with a mean percent error of −0.2% and greater than 92% of estimates within 15% of birth weight ( P < .05). Nineteen sonographic fetal weight estimation models (82.6%) better predicted fetal weight at 4 to 7 days before delivery ( P < .001). Twenty‐two (95%) of the models were less accurate at the extreme ends of fetal weight. Conclusions: Different formulas for fetal weight estimation vary greatly; we recommend that each center should evaluate the most accurate formula according to its attending population. Estimation of fetal weight performed 4 to 7 days before delivery using most models was more accurate than estimations performed 3 days before delivery.