title: Thrombocytopenia among extremely low birth weight neonates: data from a multihospital healthcare system.
abstract: OBJECTIVE
  Thrombocytopenia is common in neonatal intensive care units (NICU), with 18 to 35% of patients developing this problem before hospital discharge. It might be even more common among extremely low birth weight neonates (ELBW, < or = 1000 g birth weight). However, little is known about thrombocytopenia in the ELBW population. We sought to determine the incidence, timing, causes, platelet transfusions given, and outcomes of thrombocytopenia among ELBW neonates.
  
  
  METHODS
  We performed a cohort analysis of all 284 ELBW neonates born during 2003 and 2004 cared for in any of the Intermountain Healthcare level III NICUs.
  
  
  RESULTS
  Multiple platelet counts were obtained in all 284 (range, 4 to 441 platelet counts/patient). Of the 284, 208 (73%) had one or more platelet counts < or =150 000/microl. Most were detected during the first days of life; 80% were detected during the first week and only 20% were detected thereafter. Thrombcytopenia was more common among the smallest patients; 85% incidence among those < or =800 g, 60% among those 801 to 900 g, and 53% among those 901 to 1000 g. Platelet transfusions were given to 129 of the 208 thrombocytopenic neonates. More than 90% were given prophylactically (the patient was not bleeding). The mortality rate among those that received platelet transfusions was twice that of those that received no platelet transfusions (P < 0.01). In 48% of cases, the cause of the thrombocytopenia went undiagnosed. The most common explanations were being small for gestational age or delivered to a hypertensive mother, DIC, bacterial infection, fungal infection, and necrotizing enterocolitis, respectively.
  
  
  CONCLUSIONS
  We observed thrombocytopenia among ELBW neonates at a rate more than twice that reported among the general NICU population. Much remains to be discovered about the etiology and best treatments of thrombocytopenia among ELBW neonates.
authors.affiliation: Intermountain Healthcare Clinical Research, McKay-Dee Hospital Center, Ogden, UT 84403, USA. rdchris@ihc.com
authors.forename: R D
authors.initials: RD
authors.lastname: Christensen
authors.forename: E
authors.initials: E
authors.lastname: Henry
authors.forename: S E
authors.initials: SE
authors.lastname: Wiedmeier
authors.forename: R A
authors.initials: RA
authors.lastname: Stoddard
authors.forename: M C
authors.initials: MC
authors.lastname: Sola-Visner
authors.forename: D K
authors.initials: DK
authors.lastname: Lambert
authors.forename: T I
authors.initials: TI
authors.lastname: Kiehn
authors.forename: S
authors.initials: S
authors.lastname: Ainsworth
mesh_terms: D015331:Cohort Studies; D003695:Delivery of Health Care / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007226:Infant Mortality; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D008499:Medical Records; D009096:Multi-Institutional Systems / Q000706:statistics & numerical data*; D010976:Platelet Count; D017713:Platelet Transfusion / Q000706:statistics & numerical data; D013921:Thrombocytopenia / Q000097:blood / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D014481:United States / Q000453:epidemiology