title: Waist Circumference as a Predictor of Failure of Sonographic Estimation of Fetal Birth Weight.
abstract: OBJECTIVE
  Several factors may interfere with the success of fetal birth weight (BW) prediction. In this study we tried to determine the most probable factors that may lead to unsuccessful BW estimation.
  
  
  METHODS
  200 consecutive pregnancies between 34 and 41 weeks of gestation were enrolled for the study. All subjects underwent sonographic fetal BW estimation before membrane rupture or engagement of presented part. Sonography was performed by the same sonographer blinded to the study design. Failure of estimation was determined when deviation was found to be >15%.
  
  
  RESULTS
  Both amniotic fluid index (AUC = 0.768, p < 0.001) and maternal waist circumference (AUC = 0.698, p = 0.004) were significant predictors for failure of estimation. Optimal cut-off values were 80 mm for amniotic fluid index (77% sensitivity, 65% specificity) and 105 cm for maternal waist circumference (70% sensitivity, 61% specificity). The number of pregnancies with anteriorly located placenta was significantly higher in the group with failed estimation (12/20 vs. 39/180, p = 0.001).
  
  
  CONCLUSIONS
  Amniotic fluid volume, body mass index, maternal waist circumference and placental location may all cause failure of fetal weight estimation and may need to be adjusted. Moreover, our results indicate that waist circumference may be a more reliable predictor of failure of fetal weight estimation compared to body mass index.
authors.affiliation: Department of Obstetrics and Gynecology, Dr. Sami Ulus Women's and Children's Health Training and Research Hospital, Ankara, Turkey.
authors.forename: Ismail Burak
authors.initials: IB
authors.lastname: Gultekin
authors.forename: Orhan
authors.initials: O
authors.lastname: Altinboga
authors.forename: Enis
authors.initials: E
authors.lastname: Ozkaya
authors.forename: Serap
authors.initials: S
authors.lastname: Gultekin
authors.forename: Selma
authors.initials: S
authors.lastname: Mahmutoglu
authors.forename: Osman Fadil
authors.initials: OF
authors.lastname: Kara
authors.forename: Tuncay
authors.initials: T
authors.lastname: Kucukozkan
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000000981:diagnostic imaging; D001724:Birth Weight / Q000502:physiology*; D015992:Body Mass Index; D005260:Female; D006801:Humans; D010920:Placenta / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011247:Pregnancy; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D016216:Ultrasonography, Prenatal / Q000592:standards*; D055105:Waist Circumference / Q000502:physiology*