Factors associated with more than 500 grams inaccuracy in sonographic fetal weight estimation

Natav Hendin, Gabriel Levin, Abraham Tsur, Hadas Llan, Amihai Rottenstreich, Raanan Meyer*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Background: The sonographic assessment of estimated fetal weight (EFW) is essential for identification of fetuses in weight extremes and aids in peripartum management. However, there are inconsistent reports regarding EFW accuracy. Objective: To examine maternal and fetal determinants associated with unreliable EFW. Methods: A retrospective case-control study was conducted at a single, tertiary medical center between 2011 and 2019. All term, singleton deliveries with a sonographic EFW within 2 weeks of delivery were included. Unreliable EFW was defined as > 500 grams discordance between it and the actual birth weight. We allocated the study cohort into two groups: unreliable EFW (cases) and accurate EFW (controls). Results: Overall, 41,261 deliveries met inclusion criteria. Of these, 1721 (4.17%) had unreliable EFW. The factors positively associated with unreliable EFW included body mass index > 30 kg/m2, weight gain > 20 kg, higher amniotic fluid index, progestational diabetes, gestational age > 410/7, and birth weight > 4000 grams. On multiple regression analysis, progestational diabetes (odds ratio [OR] 2.22,95% confidence interval [95%CI] 1.56-3.17, P< 0.001) and a higher birth weight (OR 1.91,95%C11.79-2.04, P < 0.001) were independently associated with unreliable EFW. On analysis of different weight categories, progestational diabetes was associated with unreliable EFW only among birth weights a 3500 grams (OR 3.28,95%C11.98-5.44, P< 0.001) and £ 4000 grams (OR 4.27,95%CI 2.31-7.90, P< 0.001). Conclusion: Progestational diabetes and increased birth weight are independent risk factors for unreliable EFW and should be considered when planning delivery management.

Original languageEnglish
Pages (from-to)43-47
Number of pages5
JournalIsrael Medical Association Journal
Issue number1
StatePublished - Jan 2021


  • Birth weight
  • Estimated fetal weight (EFW)
  • Progestational diabetes
  • Ultrasound


Dive into the research topics of 'Factors associated with more than 500 grams inaccuracy in sonographic fetal weight estimation'. Together they form a unique fingerprint.

Cite this