title: Predicting periviable birthweight and survival: bedside ultrasound versus anatomy scan gestational adjusted age projection.
abstract: OBJECTIVE
  Two methods of birthweight (BW) prediction in the periviable period: bedside ultrasound proximate to delivery versus gestation-adjusted-projection (GAP) method was compared.
  
  
  METHODS
  Periviable births were identified over a 6-year period. The GAP method was applied to the estimated fetal weight (EFW) from anatomy scans and the gestational age at delivery to predict BW, designated EFWGAP. EFW from the bedside ultrasound (EFWUS), and the EFWGAPwere compared to actual BW to calculate absolute values of error in BW estimates. Neonatal survival estimates were made utilizing a National Institute of Child Health and Human Development calculator.
  
  
  RESULTS
  EFWUSwas more accurate than EFWGAPin predicting BW as the mean absolute value of error with bedside ultrasound ǀEFWUS-BWǀ was significantly lower than mean absolute value of error with GAP method ǀEFWGAP-BWǀ, 75.32 ± 74.64 g versus 125.68 ± 130.62 g, p = 0.01. Predicted neonatal survival based on EBWUSwas closer to reference than predicted survival based on EBWGAP9.66% ± 9.43% versus 7.76% ± 7.78% p = 0.26.
  
  
  CONCLUSIONS
  EFWUSis more accurate than EFWGAPfor predicting BW in this period. However, the GAP technique could have utility in survival predictions when timely performance of ultrasound is not feasible.
authors.affiliation: a Department of Obstetrics and Gynecology , Albany Medical Center , Albany, NY, USA.
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Keller
authors.affiliation: b Department of Maternal Fetal Medicine , Albany Medical Center , Albany, NY, USA.
authors.forename: Craig M
authors.initials: CM
authors.lastname: Zelig
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000502:physiology*; D005260:Female; D005328:Fetal Viability / Q000502:physiology*; D020567:Fetal Weight / Q000502:physiology*; D005865:Gestational Age; D057238:Growth Charts; D006801:Humans; D007231:Infant, Newborn; D000067716:Point-of-Care Testing / Q000592:standards; D011237:Predictive Value of Tests; D011247:Pregnancy; D011379:Prognosis; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal / Q000379:methods*
keywords: Periviable period; fetal weight ratio; gestation-adjusted projection; hadlock; ultrasound competency