title: Serum levels of caffeine in umbilical cord and apnea of prematurity.
abstract: OBJECTIVE
  To determine the influence of presence of caffeine in umbilical cord blood on apnea occurrence.
  
  
  METHODS
  A prospective cohort study with preterm newborns with birth weight lower than 2,000 g was undertaken. Exclusion criteria were: mothers who received opioids; mechanical ventilation during the first 4 days of life; cerebral and major cardiac malformations; perinatal asphyxia; severe periintraventricular hemorrhage; exchange transfusion before the fourth day of life; and those who received methylxanthine prior to extubation. Neonates were divided into detectable and undetectable caffeine in umbilical cord blood. Newborns were followed for the first 4 days for occurrence of apnea spells.
  
  
  RESULTS
  Eighty-seven newborns with and 40 without detectable caffeine in umbilical cord blood were studied. Median caffeine concentration of the 87 patients with detectable caffeine in umbilical blood was 2.3 microg/mL (0.2-9.4 microg/mL). There was no association between occurrence of apnea spells and presence of caffeine in umbilical cord blood. Neonates with detectable caffeine in umbilical blood had borderline later apnea (66.3+/-4.14 hours) than those with undetectable levels (54.2+/-6.26 hours).
  
  
  CONCLUSIONS
  Detected levels of caffeine in umbilical cord blood did not decrease occurrence of apnea of prematurity, but it had a borderline effect delaying its occurrence, suggesting that even a low level of caffeine in umbilical cord blood might delay occurrence of apnea spells.
authors.affiliation: Department of Pediatrics, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Cláudia Regina
authors.initials: CR
authors.lastname: Hentges
authors.forename: Renata Rostirola
authors.initials: RR
authors.lastname: Guedes
authors.forename: Rita C
authors.initials: RC
authors.lastname: Silveira
authors.forename: Renato S
authors.initials: RS
authors.lastname: Procianoy
mesh_terms: D001049:Apnea / Q000097:blood / Q000139:chemically induced*; D001938:Brazil; D002110:Caffeine / Q000009:adverse effects / Q000097:blood*; D000697:Central Nervous System Stimulants / Q000009:adverse effects / Q000097:blood*; D004812:Epidemiologic Methods; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000097:blood / Q000139:chemically induced*; D008297:Male; D013997:Time Factors
chemical_list: D000697:Central Nervous System Stimulants; D002110:Caffeine