Does the level of amniotic fluid have an effect on the accuracy of sonographic estimated fetal weight at term?

Eran Ashwal, Liran Hiersch, Nir Melamed, Ron Bardin, Arnon Wiznitzer, Yariv Yogev

Research output: Contribution to journalArticlepeer-review


Objective: Controversy exists concerning the impact of amniotic fluid index (AFI) on the accuracy of sonographic estimation of fetal weight (EFW). Thus, we aimed to evaluate whether differences in AFI has an influence on the accuracy of sonographic EFW. Methods: All term, singleton pregnancies which underwent a sonographic EFW and measurement of AFI within a week from delivery were included. Cases were stratified into three categories according to AFI: (1) Normal AFI (51-249 mm), (2) Oligohydramnios (AFI ≤ 50 mm) and (3) Polyhydramnios (AFI ≥ 250 mm). Inaccurate EFW was defined if there was more than 15% difference between sonographic EFW and actual birthweight. Results: Overall, 1746 pregnancies were identified (1096 with normal AFI, 455 with oligohydramnios and 195 with polyhydramnios). Mean AFI was 115.8 ± 60 mm, 28.1 ± 13 mm and 293 ± 35 mm, p < 0.001, and mean sonographic EFW was 3182.5 ± 573 g, 3118.8 ± 517 g and 3713.2 ± 461 g, p < 0.001, respectively. Demographic data and gestational age at delivery were similar. Mean birthweight was 3221.7 ± 535 g, 3132.5 ± 505 g and 3654.1 ± 480 g, p < 0.001, respectively. The rate of inaccurate EFW was similar between the groups (8.4%, 8.7% and 9.7%, p = 0.19, respectively). On multivariate analysis, AFI was not associated with EFW inaccuracy (OR 1.01, 95% C.I 0.67-1.54, p = 0.93). Conclusion: AFI has limited impact on the percentage of errors in sonographic fetal weight estimation a week prior delivery.

Original languageEnglish
Pages (from-to)638-642
Number of pages5
JournalJournal of Maternal-Fetal and Neonatal Medicine
Issue number6
StatePublished - 1 Apr 2015


  • Amniotic fluid index
  • Fetal weight
  • Oligohydramnios
  • Polyhydramnios
  • Ultrasound


Dive into the research topics of 'Does the level of amniotic fluid have an effect on the accuracy of sonographic estimated fetal weight at term?'. Together they form a unique fingerprint.

Cite this