title: Predicting Nonhemolytic Neonatal Hyperbilirubinemia.
abstract: BACKGROUND
  Before hospital discharge, newborn infants should be assessed for the risk of excessive hyperbilirubinemia. We determined maternal and obstetric risk factors for hyperbilirubinemia in infants born at term (gestational age ≥37 weeks) to form an individualized risk assessment tool for clinical use.
  
  
  METHODS
  This was a population-based study with data from the Swedish Medical Birth Register from 1999 to 2012, including 1,261,948 singleton infants. Outcome was defined as infants diagnosed with hyperbilirubinemia (N = 23,711), excluding all cases of hemolytic (immune-mediated or other specified hemolytic) diseases of the newborn.
  
  
  RESULTS
  Risk factors with an adjusted odds ratio (aOR) for neonatal hyperbilirubinemia of ≥1.5 (medium-sized effect or more) were gestational age 37 to 38 weeks (aOR = 2.83), failed vacuum extraction (aOR = 2.79), vacuum extraction (aOR = 2.22), Asian mother (aOR = 2.09), primipara (aOR = 2.06), large-for-gestational-age infant (aOR = 1.84), obese mother (aOR = 1.83), and small-for-gestational-age infant (aOR = 1.66). Planned cesarean delivery (CD) was associated with a reduced risk (aOR = 0.45). Without any of these risk factors (normal birth weight infant delivered vaginally at 39 to 41 weeks' gestation by a non-Asian, nonobese, multiparous mother) the rate of nonhemolytic neonatal hyperbilirubinemia was 0.7%. In relation to the combined load of different risk factors, rates of neonatal hyperbilirubinemia ranged from 0.2% to 25%.
  
  
  CONCLUSIONS
  Collection of a few easily available maternal and obstetric risk factors predicts >100-fold variation in the incidence of neonatal hyperbilirubinemia. The information provided herein enables individualized risk prediction with interactions between different risk factors taken into account.
authors.affiliation: Divisions of Pediatrics, Department of Clinical Science, Intervention and Technology, Department of Neonatal Medicine, Karolinska University Hospital, Stockholm, Sweden; and mikael.norman@ki.se.
authors.forename: Mikael
authors.initials: M
authors.lastname: Norman
authors.affiliation: Reproductive Health, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden and.
authors.forename: Katarina
authors.initials: K
authors.lastname: Åberg
authors.affiliation: IVF Clinic Umeå, IVF Sweden AB, Umeå, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Holmsten
authors.affiliation: Department of Obstetrics and Gynecology.
authors.forename: Vania
authors.initials: V
authors.lastname: Weibel
authors.affiliation: Reproductive Health, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden and.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Ekéus
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D051556:Hyperbilirubinemia, Neonatal / Q000175:diagnosis* / Q000209:etiology; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D009035:Mothers; D011247:Pregnancy; D011248:Pregnancy Complications; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D013548:Sweden