title: Prenatal tobacco exposure influences cerebral oxygenation in preterm infants.
abstract: OBJECTIVE
  Our aim was to determine the influence of prenatal tobacco exposure on regional cerebral tissue oxygen saturation (r(c)SO(2)) and fractional tissue oxygen extraction (FTOE) in preterm infants. We hypothesized that as a result of vasoconstriction caused by prenatal tobacco exposure r(c)SO(2) would be lower and FTOE would be higher during the first days after birth in infants exposed to tobacco during pregnancy.
  
  
  METHODS
  Sixty preterms were included in this prospective, observational cohort study (median gestational age 29.9 weeks, range 26.0-31.8, median birth weight 1248 g, range 615-2250). Fourteen infants had been exposed to tobacco during pregnancy. All mothers smoked more than five cigarettes a day till delivery. We measured r(c)SO(2) and transcutaneous arterial oxygen saturation (tcSaO(2)) in all infants on days 1-5, 8, and 15. FTOE was calculated: FTOE=(tcSaO(2)-r(c)SO(2))/tcSaO(2).
  
  
  RESULTS
  In preterm infants exposed to tobacco during pregnancy, r(c)SO(2) was lower during days 1, 2, and 8 after birth, median 73% versus 81%, 73% versus 80% and 71% versus 78% respectively. FTOE was higher during days 1 and 8 after birth, median 0.24 versus 0.15 and 0.26 versus 0.19 respectively. On the second day, FTOE tended to be higher, 0.18 versus 0.14.
  
  
  CONCLUSIONS
  During the first two days and day 8 after birth cerebral oxygen saturation is lower and oxygen extraction higher in preterm infants following prenatal tobacco exposure. Our data suggest that prenatal tobacco exposure may have an effect on cerebral oxygenation of the infant.
authors.affiliation: Division of Neonatology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, the Netherlands. e.a.verhagen@bkk.umcg.nl
authors.forename: Elise A
authors.initials: EA
authors.lastname: Verhagen
authors.forename: Hendrik J
authors.initials: HJ
authors.lastname: Ter Horst
authors.forename: Elisabeth M W
authors.initials: EM
authors.lastname: Kooi
authors.forename: Paul
authors.initials: P
authors.lastname: Keating
authors.forename: Paul P
authors.initials: PP
authors.lastname: van den Berg
authors.forename: Arend F
authors.initials: AF
authors.lastname: Bos
mesh_terms: D001724:Birth Weight / Q000187:drug effects; D001784:Blood Gas Analysis; D054022:Cerebrum / Q000378:metabolism*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000503:physiopathology*; D012907:Smoking / Q000009:adverse effects*; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D010100:Oxygen