title: Umbilical coiling index in normal and complicated pregnancies.
abstract: OBJECTIVE
  To estimate the relation between undercoiling and overcoiling of the umbilical cord and adverse pregnancy outcome.
  
  
  METHODS
  Umbilical cords and hospital records of 885 patients were studied in a cross-sectional study design. The umbilical coiling index was determined as the number of complete coils divided by the length of the cord in centimeters, blinded for pregnancy outcome. Obstetric history and pregnancy outcome of each patient were obtained from hospital records, blinded for the umbilical coiling index. Odds ratios and their 95% confidence intervals were calculated to evaluate associations between undercoiling and overcoiling and adverse pregnancy outcome, using multiple logistic regression.
  
  
  RESULTS
  Undercoiling (umbilical coiling index below the 10th percentile, using references values from uncomplicated pregnancies) was associated with fetal death (odds ratio [OR] 3.35, 95% confidence interval [CI] 1.48-7.63), spontaneous preterm delivery (OR 2.16, 95% CI 1.34-3.48), trisomies (OR 5.79, 95% CI 2.07-16.24), low Apgar score at 5 minutes (OR 3.14, 95% CI 1.47-6.70), velamentous cord insertion (OR 3.00, 95% CI 1.16-7.76), single umbilical artery (OR 3.68, 95% CI 1.26-10.79), and dextral coiling (OR 1.80, 95% CI 1.02-3.17). Overcoiling (umbilical coiling index above the 90th percentile) was associated with asphyxia (OR 4.16, 95% CI 1.30-13.36), umbilical arterial pH < 7.05 (OR 2.91, 95% CI 1.05-8.09), small for gestational age infants (OR 2.10, 95% CI 1.01-4.36), trisomies (OR 9.26, 95% CI 2.84-30.2), single umbilical artery (OR 8.25, 95% CI 2.60-26.12), and sinistral coiling (OR 4.30, 95% CI 1.52-12.2).
  
  
  CONCLUSIONS
  Undercoiling and overcoiling of the umbilical cord are associated with increased risk for adverse perinatal outcome.
authors.affiliation: Departments of Obstetrics, Julius Center for Health Sciences, University Medical Center Utrecht, Utrecht, the Netherlands. mdelaat@dds.nl
authors.forename: Monique W M
authors.initials: MW
authors.lastname: de Laat
authors.forename: Arie
authors.initials: A
authors.lastname: Franx
authors.forename: Michiel L
authors.initials: ML
authors.lastname: Bots
authors.forename: Gerard H A
authors.initials: GH
authors.lastname: Visser
authors.forename: Peter G J
authors.initials: PG
authors.lastname: Nikkels
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D015999:Multivariate Analysis; D011247:Pregnancy; D011248:Pregnancy Complications / Q000473:pathology*; D011256:Pregnancy Outcome; D014102:Torsion Abnormality; D014470:Umbilical Cord / Q000473:pathology*