Skip to main content
SMFM 2024 Pregnancy Meeting Main banner
Final Program


Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.
Presentation Icons
Additional registration fee required
Additional registration fee required
Faculty have requested this content not be shared on social media
Faculty have requested this content not be shared on social media
CME Credit Offered
CME Credit Offered
Poster Icons
Foundation Awardee
Foundation Awardee
No Social Media
No Social Media
Back
Q&A

Ultrasound/Imaging

Poster Session 1

(173) Accuracy of Estimated Fetal Weight Based on Provider Training Level

Tuesday, February 13, 2024
10:30 AM – 12:00 PM  
Location: Prince George's Exhibit Hall CDE, Lower Atrium Level
Foundation Awardee
Objective: Ultrasound (US) and clinical palpation can be used to determine an estimated fetal weight (EFW). We aimed to determine the accuracy of these measures performed by providers at various training levels.

Study Design: This is a secondary analysis of a prospective cohort study of term singleton gravidas with obesity admitted for delivery. EFW was obtained with US-derived biometry and clinician palpation via Leopold’s maneuvers. The primary outcome was prediction of birthweight within 500g. Secondary outcomes included accuracy within 250g and prediction of small-for-gestational age (SGA, < 10%ile) and large-for-gestational age (LGA, >90%ile) birthweight as measured by area under receiver-operating characteristic curves. (AUCs). These outcomes were compared by provider level of training: post-graduate years (PGY) 1-2, PGY 3-4, and post-residency (fellows and attendings).

Results: Of 243 patients, 46.9% of EFW were performed by PGY 1-2, 23.0% by PGY 3-4, and 30.0% by post-residency providers. Baseline characteristics were similar. There was no difference in accuracy of US or palpation within 500g or US within 250g between the groups (Figure). However, the more junior providers were more likely to accurately predict birthweight within 250g by palpation (p=0.01). SGA was most likely to be accurately predicted by PGY3-4 providers via US (AUC 0.94 [0.90-0.99] vs 0.74 [0.50-0.98] for PGY1-2 and 0.66 [0.43-0.88] for post-residency, p=0.02) and by PGY1-2 providers by palpation (AUC 0.77 [0.53-1.00] vs 0.62 [ 0.37-0.86] for PGY3-4 and 0.49 [0.46-0.51] for post-residency, p=0.04). There was no difference in LGA prediction by training level.

Conclusion: Overall accuracy of EFW by US is similar across training levels, however accurate prediction of SGA by US is highest among PGY3-4 providers. By clinical palpation, PGY 1-2 providers are most likely to accurately assess fetal weight. This may suggest that as training progresses, US replaces palpation as preferred EFW method. Overall, trainees’ estimates of fetal weight are similarly accurate to post-residency providers’ and can be used to guide clinical management.