title: Finding the best formula to predict the fetal weight: comparison of 18 formulas.
abstract: BACKGROUND
  To compare the accuracy of 18 formulas in predicting fetal weight and also to make a comparison of these formulas in low-birth-weight fetuses (<2,500 g) and in fetuses weighing >4,000 g.
  
  
  METHODS
  Four-hundred-and-ninety-five pregnant patients were enrolled. The estimated fetal weight was calculated using 18 different formulas. The mean percentage error, the mean absolute percentage error and reliability analysis were used to compare the performance of the formulas.
  
  
  RESULTS
  The Cronbach's alpha was the highest in the formulas Hadlock I (0.977 (95% CI = 0.972-0.980)), Hadlock III (0.977 (95% CI = 0.972-0.980)) and Ott (0.975 (95% CI = 0.970-0.979)) in all fetuses. It was the highest in formulas Ott (0.383 (95% CI = 0.091-0.581)), Hadlock IV (0.371 (95% CI = 0.074-0.572)) and Combs (0.369 (95% CI = 0.071-0.571)) in fetuses >4,000 g. It was the highest in formulas Coombs (0.957 (95% CI = 0.940-0.569)), Ott (0.956 (95% CI = 0.939-0.968)) and Hadlock IV (95% CI = 0.956 (0.938-0.968)) in fetuses <2,500 g.
  
  
  CONCLUSIONS
  We noted that formulas Hadlock I, Hadlock III and Ott may be used to predict the estimated fetal weight accurately in all fetuses in our study. Formulas Ott, Hadlock IV and Coombs may be preferred to predict EFW in fetuses <2,500 g and >4,000 g. Better formulas should be developed to predict the fetal weight in fetuses >4,000 g.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal and Fetal Medicine, Etlik Zubeyde Hanim Maternity Hospital, Ankara, Turkey.
authors.forename: Deniz
authors.initials: D
authors.lastname: Esinler
authors.forename: Oya
authors.initials: O
authors.lastname: Bircan
authors.forename: Sertac
authors.initials: S
authors.lastname: Esin
authors.forename: Elif Gulsah
authors.initials: EG
authors.lastname: Sahin
authors.forename: Omer
authors.initials: O
authors.lastname: Kandemir
authors.forename: Serdar
authors.initials: S
authors.lastname: Yalvac
mesh_terms: D000328:Adult; D000465:Algorithms; D000886:Anthropometry; D001724:Birth Weight / Q000502:physiology*; D005260:Female; D005320:Fetal Macrosomia / Q000175:diagnosis; D020567:Fetal Weight / Q000502:physiology*; D006801:Humans; D007230:Infant, Low Birth Weight; D011247:Pregnancy; D011379:Prognosis; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal / Q000379:methods*