title: Haemolytic and nonhaemolytic neonatal jaundice have different risk factor profiles.
abstract: OBJECTIVE
  This study examined maternal and pregnancy risk factors for haemolytic and nonhaemolytic neonatal jaundice in a large population-based cohort study.
  
  
  METHODS
  We conducted a cohort study of 1 019 220 singleton live births from the Swedish medical birth register from 1987 to 2002, using information on neonatal jaundice and maternal and pregnancy characteristics. Diagnoses of gestational hypertensive disorders were obtained by linkage to the national inpatient register. Multivariate logistic regression analysis provided odds ratios for the risk factors of both forms of jaundice.
  
  
  RESULTS
  A total of 6057 (0.6%) births were affected by haemolytic jaundice and 36 869 (3.6%) by nonhaemolytic jaundice. The strongest risk factors for haemolytic jaundice were maternal alloimmunisation, blood group O and neonatal jaundice in older siblings. For nonhaemolytic jaundice, the strongest risk factors were preterm birth, neonatal jaundice in older siblings, maternal origin from East or South-East Asia and maternal obesity. We estimated that 13% of haemolytic jaundice was attributable to alloimmunisation and 39% of nonhaemolytic jaundice was attributable to preterm birth.
  
  
  CONCLUSIONS
  Haemolytic and nonhaemolytic neonatal jaundice had different risk factor profiles. Interventions to reduce maternal alloimmunisation, preterm birth and maternal obesity may lower the prevalence of neonatal jaundice and the risk of consequent neurological complications.
authors.affiliation: Department of Epidemiology and Biostatistics, Drexel University School of Public Health, Philadelphia, PA, USA.|Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Lee
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Le Ray
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Ji Yu
authors.initials: JY
authors.lastname: Sun
authors.affiliation: Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.|Department of Clinical Immunology and Transfusion Medicine, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Agneta
authors.initials: A
authors.lastname: Wikman
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Reilly
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine, Karolinska Institutet, Stockholm, Sweden.|Department of Clinical Science and Education, Sachs' Children and Youth Hospital, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Stefan
authors.initials: S
authors.lastname: Johansson
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006461:Hemolysis; D006801:Humans; D007567:Jaundice, Neonatal / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D011247:Pregnancy; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
keywords: ABO blood group; Alloimmunisation; Haemolytic hyperbilirubinemia; Nonhaemolytic hyperbilirubinemia; Rhesus negative