EP08.36: Estimated fetal weight: reassessing our accuracy

In total 230 scans paired with birthweights were reviewed. The overall mean error was 6.0% (SD 4.3%). 100% EFWa within 20% of BW 97.0% EFWa within 15% of BW 80.9% EFWa within 10% of BW Composite figures for scans within three days (n = 58) were 100%, 96.6%, and 81.0% respectively. 50 babies (12%) were SGA at birth with a GROW centile < 10th. Of these, 38/50 (76%) had growth scans within 2 weeks of delivery and 24/50 (48%) were correctly identified as being SGA ahead of birth. Overall EFW calculations are within an acceptable degree of accuracy and have improved since the last audit (Hanton and Hughes, 2022). Sub-analyses were not consistently met, perhaps due to smaller sample sizes. 12/50 (24%) SGA babies at delivery were potentially missed due to not having a scan within 14 days of delivery. Continued monitoring of EFW accuracy and further incremental improvements will help clinicians rely on the accuracy of fetal weight estimates.