title: The impact of length of second stage of labor on shoulder dystocia outcomes: a retrospective cohort study.
abstract: OBJECTIVE
  To compare obstetrical and neonatal outcomes of vaginal deliveries complicated by shoulder dystocia, according to the length of second stage of labor.
  
  
  METHODS
  We conducted a retrospective cohort study of 177 shoulder dystocia cases that were divided into three categories according to second stage duration (1-20, 21-59, 60-180 min, respectively). The three categories were compared in terms of obstetric characteristics and neonatal outcomes. Statistical analysis utilized the χ2-test and analysis of variance where appropriate. The odds ratios of brachial plexus injury and having a 5-min APGAR score <7 across the second stage duration categories were calculated using logistic regression models that adjusted for potential confounders.
  
  
  RESULTS
  The incidence of brachial plexus injury was 5.4% (1st category), 4.4% (2nd category) and 26.9% (3rd category); P<0.01. The higher incidence of brachial plexus injury in the group where second stage lasted >1 h was confirmed by logistic regression, with and without adjusting for confounders.
  
  
  CONCLUSIONS
  The incidence of brachial plexus injury increases with the length of second stage, even after controlling for confounders.
authors: Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Abington Memorial Hospital, Abington, PA, USA. vmoragia@bidmc.harvard.edu
authors: Vasiliki A
authors: VA
authors: Moragianni
authors: Michele R
authors: MR
authors: Hacker
authors: Frank J
authors: FJ
authors: Craparo
mesh_terms: D000328:Adult; D001720:Birth Injuries / Q000209:etiology; D001917:Brachial Plexus / Q000293:injuries; D015331:Cohort Studies; D004420:Dystocia / Q000503:physiopathology*; D005260:Female; D005320:Fetal Macrosomia / Q000150:complications; D006801:Humans; D007231:Infant, Newborn; D007748:Labor Stage, Second / Q000502:physiology*; D016015:Logistic Models; D011247:Pregnancy; D012189:Retrospective Studies; D012782:Shoulder; D013997:Time Factors