Development of individual growth standards for estimated fetal weight: II. Weight prediction during the third trimester and at birth

✍ Scribed by Russell L. Deter; Ivar K. Rossavik; Robert J. Carpenter

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 568 KB
• Volume: 17
• Category: Article
• ISSN: 0091-2751
• DOI: 10.1002/jcu.1870170203

✦ Synopsis

Using a weight estimation procedure based of the Rossavik growth model, we have evaluated the possibility of establishing individual growth cuwe standards for fetal weight estimates and of predicting birth weights in the second trimester. In 20 normal fetuses delivered at term, 95% of the weight estimates obtained after 26 weeks' menstrual age (MA) were within 2 22% of the predicted weight estimates. In these same fetuses the mean difference between birth weight estimates based on growth patterns before 26 weeks, MA, and actual birth weights was 1.2%, with 95% of the percent deviations being between 13.3% and -8.8%. In a similar prospective study, the mean percent difference was -1.7%, with a range of 9.6% to -13.6%.

Direct comparison of weight estimates obtained during the last week before delivery with birth weight projections indicated that birth weight estimates obtained 14 weeks before delivery had smaller systematic and random errors than those obtained within a week of delivery. These results indicate that individual growth curve standards for fetal weight estimates and the growth potential of individual fetuses can be determined from growth patterns in the second trimester. Indexing Words: Estimated fetal weight -Individual growth cuwe standards Birth weight projections Fetal weight estimation is a standard part of the comprehensive ultrasound assessment of growth' and obstetrical management decisions are frequently based on such weight estimates. Evaluation of weight estimates obtained with ultrasound usually involves a comparison with agedependent standards that have been developed in cross-sectional studies of large sample^.^,^ However, the normal range found in most studies is usually quite broad, being more that 1000 g at all time points after 29 weeks even when conservative boundaries such as the 10th and From the