title: Second-trimester miscarriage and umbilical cord knot. Case report and review of the literature.
abstract: OBJECTIVE
  The present study presents a case with an umbilical cord knot along with extensive literature review.
  
  
  METHODS
  Presentation of a rare case of second-trimester abortion which was attributed to a tight umbilical cord knot. Furthermore the authors reviewed the literature from 1952 to 2012 in order to compare impact of knots on intrapartum and perinatal outcomes.
  
  
  RESULTS
  Four large retrospective studies assessed several predisposing factors. Long umbilical cords, male embryos, and multiparity were correlated with knots in three of these studies. Data regarding perinatal effects of true knots from three studies were summarized and compared.
  
  
  CONCLUSIONS
  Umbilical cord true knots during the second trimester could be a very rare cause of abortion. The presence of knots during the third trimester and labor do not seem to be associated with increased perinatal and intrapartum morbidity and mortality, although there is still some controversy in the literature on this topic.
authors.affiliation: Second Department of Obstetrics and Gynecology, University of Athens, Aretaieion Hospital, Athens, Greece. P_bakas@yahoo.com
authors.forename: P
authors.initials: P
authors.lastname: Bakas
authors.forename: E
authors.initials: E
authors.lastname: Papadakis
authors.forename: D
authors.initials: D
authors.lastname: Hassiakos
authors.forename: A
authors.initials: A
authors.lastname: Liapis
mesh_terms: D000022:Abortion, Spontaneous / Q000209:etiology*; D000328:Adult; D005260:Female; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology / Q000473:pathology*; D011262:Pregnancy Trimester, Second; D012307:Risk Factors; D014470:Umbilical Cord / Q000473:pathology*