title: The relationship between umbilical cord length and chronic rheumatic heart disease: a prospective cohort study.
abstract: BACKGROUND
  One previous, preliminary study reported that the length of the umbilical cord at birth is related to the risk of developing chronic rheumatic heart disease in later life. We sought to replicate this finding.
  
  
  METHODS
  Prospective, population-based birth cohort.
  
  
  METHODS
  We traced 11,580 individuals born between 1915 and 1929 in Uppsala, Sweden. We identified cases with a main or secondary diagnosis of chronic rheumatic heart disease in the Swedish national inpatient, outpatient or death registers. Archived obstetric records provided data on umbilical cord length, gestational age, birthweight and placental weight.
  
  
  RESULTS
  There were 136 patients with chronic rheumatic heart disease (72 men and 64 women) with a mean age at first hospital admission of 68 years (range 36-92). There was evidence of a positive association between umbilical cord length and risk of subsequent chronic rheumatic heart disease. The overall hazard ratio in the Swedish study (1.13, 95% confidence interval 1.01 to 1.27) was similar to that of the previous study, with some suggestion of larger effect in men than in women. No other birth characteristics were predictive except for weak evidence of a protective effect of higher birthweight in men.
  
  
  CONCLUSIONS
  People with longer umbilical cords at birth are more likely to develop chronic rheumatic heart disease in later life. As longer umbilical cords have more spiral arteries and a higher vascular resistance, we hypothesize that the increased pressure load on the heart leads to changes in endothelial biology and increased vulnerability to the autoimmune process initiated by infection with β-haemolytic streptococci.
authors: Centre for Health Equity Studies, Karolinska Institutet/Stockholm University, Sweden Department for Epidemiology and Population Health, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, UK.
authors: Anna
authors: A
authors: Goodman
authors: Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland Department of Obstetrics and Gynaecology, Oulu University Hospital and University of Oulu, Finland Hospital for Children and Adolescents, Helsinki University Central Hospital and University of Helsinki, Finland.
authors: Eero
authors: E
authors: Kajantie
authors: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, UK.
authors: Clive
authors: C
authors: Osmond
authors: Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland Department of General Practice and Primary Health Care, University of Helsinki, Finland Vasa Central Hospital, Finland Folkhälsan Research Centre, Helsinki, Finland.
authors: Johan
authors: J
authors: Eriksson
authors: Centre for Health Equity Studies, Karolinska Institutet/Stockholm University, Sweden.
authors: Ilona
authors: I
authors: Koupil
authors: Heart Research Center, Oregon Health and Science University, Portland, USA.
authors: Kent
authors: K
authors: Thornburg
authors: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, UK diwp@mrc.soton.ac.uk.
authors: David I W
authors: DI
authors: Phillips
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D010343:Patient Admission; D011446:Prospective Studies; D012042:Registries; D012214:Rheumatic Heart Disease / Q000175:diagnosis / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D014470:Umbilical Cord / Q000033:anatomy & histology*
keywords: Rheumatic heart disease; birthweight; developmental origins of health and disease; foetal programming; umbilical cord