title: Obstetrical factors related to nuchal cord.
abstract: BACKGROUND
  To investigate the intrapartum factors related to umbilical cord nuchal loops (nuchal cord) with particular reference to shoulder dystocia.
  
  
  METHODS
  We studied all singleton pregnancies with a vertex presentation and a birth weight of at least 2500 g from 1 January 1978 to 31 March 1997 and the 13,717 pregnancies with nuchal cord were compared to the 44,136 without nuchal cord.
  
  
  RESULTS
  When compared to pregnant women without nuchal cord, a greater proportion of pregnant women with nuchal cord underwent induction of labor (adjusted OR 1.09, 95% CI 1.04-1.15) and augmentation with oxytocin (adjusted OR 1.06, 95% CI 1.01-1.11). They had a longer second stage of labor (p=0.0013) and a greater proportion of primiparous women with tight nuchal cord had second stage of labor that lasted longer than two hours (adjusted OR 1.21, 95% CI 1.03-1.41). The proportion of abnormal fetal heart rate patterns was higher in the presence of nuchal cord (adjusted OR 1.61, 95% CI 1.55-1.68). Shoulder dystocia occurred more commonly in association with nuchal cord, especially when the nuchal cord was tight (adjusted OR 1.50, 95% CI 1.30-1.72 for all nuchal cord; adjusted OR 1.82, 95% CI 1.42-2.34 for tight nuchal cord).
  
  
  CONCLUSIONS
  Umbilical cord nuchal loops are associated with induction of labor, slow progress of labor, and shoulder dystocia.
authors.affiliation: Department of Obstetrics and Gynecology, McGill University. Montreal, Quebec, Canada. Onome.Ogueh@bsuh.nhs.uk
authors.forename: Onome
authors.initials: O
authors.lastname: Ogueh
authors.forename: Aisha
authors.initials: A
authors.lastname: Al-Tarkait
authors.forename: Danielle
authors.initials: D
authors.lastname: Vallerand
authors.forename: Fabrice
authors.initials: F
authors.lastname: Rouah
authors.forename: Lucie
authors.initials: L
authors.lastname: Morin
authors.forename: Alice
authors.initials: A
authors.lastname: Benjamin
authors.forename: Robert H
authors.initials: RH
authors.lastname: Usher
mesh_terms: D000328:Adult; D001724:Birth Weight; D016208:Databases, Factual; D004420:Dystocia / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D007746:Labor Presentation; D011247:Pregnancy; D011256:Pregnancy Outcome; D015995:Prevalence; D011792:Quebec / Q000453:epidemiology; D012782:Shoulder; D016216:Ultrasonography, Prenatal; D014470:Umbilical Cord / Q000000981:diagnostic imaging*