title: Accuracy of estimated fetal weight in shoulder dystocia and neonatal birth injury.
abstract: OBJECTIVE
  This study was undertaken to determine whether there is any difference in the rate of error of estimated fetal weight (EFW) in cases of shoulder dystocia compared with controls.
  
  
  METHODS
  Women whose delivery was complicated by shoulder dystocia were studied and compared with a control group matched for parity, race, labor type (spontaneous or induced), and birth weight (BW). Accuracy (%) was defined as [(EFW-BW)/BW] x 100. The primary outcome of the study was rate of EFW underestimation error 20% or greater.
  
  
  RESULTS
  During the 5-year study period, there were 206 cases of shoulder dystocia that met all study criteria. There was no difference in the number of patients that had EFW underestimation error 20% or greater (shoulder dystocia 9.8% vs control 12.8%; P = .38). There was also no difference in the number of patients that had EFW underestimation error 20% or greater between shoulder dystocia with and without injury (injury 8.3% vs no injury 7.1%; P = .79).
  
  
  CONCLUSIONS
  EFW underestimation error in cases of shoulder dystocia is an infrequent event and does not occur more often than in deliveries without shoulder dystocia.
authors.affiliation: Division of Material Fetal Medicine, Department of Obstetrics & Gynecology, Hutzel Hospital, Wayne State University, Detroit, MI 48201, USA. smehta@med.wayne.edu
authors.forename: Shobha H
authors.initials: SH
authors.lastname: Mehta
authors.forename: Sean C
authors.initials: SC
authors.lastname: Blackwell
authors.forename: Israel
authors.initials: I
authors.lastname: Hendler
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bujold
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: Joel
authors.initials: J
authors.lastname: Ager
authors.forename: Todd
authors.initials: T
authors.lastname: Kraemer
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Sokol
mesh_terms: D000293:Adolescent; D000328:Adult; D001720:Birth Injuries / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D001917:Brachial Plexus / Q000293:injuries*; D016022:Case-Control Studies; D003953:Diagnosis-Related Groups / Q000706:statistics & numerical data; D004420:Dystocia / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D020567:Fetal Weight; D006801:Humans; D007231:Infant, Newborn; D008499:Medical Records; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012189:Retrospective Studies