title: Effects of maternal dexamethasone administration on fetal Doppler flow velocity waveforms.
abstract: OBJECTIVE
  To investigate the effects of maternal dexamethasone administration on umbilical and fetal cerebral artery flow velocity waveforms.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Department of Obstetrics and Gynaecology, Robert Ballanger Hospital, Aulnay-sous-Bois, France.
  
  
  METHODS
  Twenty-six pregnant women with singleton pregnancies considered at risk for preterm delivery. At baseline, all pregnancies had normal fetoplacental vascular resistance.
  
  
  METHODS
  These women were given weekly six intravenous doses of 4 mg of dexamethasone eight hours apart.
  
  
  METHODS
  Doppler studies were performed from both umbilical artery (UA) and fetal middle cerebral artery (MCA) before (day 0), during (day 2), immediately after (day 4) and shortly after (day 7) every steroid course.
  
  
  RESULTS
  No significant variation was noted in both umbilical artery pulsatility index (PI) and fetal heart rate through dexamethasone therapy. Compared with mean initial values, we found on day 4 a significant decrease in MCA PI of 0.28 (F = 7.17, P < 0.001) and a significant increase in UA:MCA PI ratio of 0.08 (F = 3.85, P = 0.013); in contrast no significant change was documented on days 2 and 7 in both MCA pulsatility index and UA:MCA PI ratio. After multiple regression analysis, only the decrease in fetal middle cerebral artery pulsatility index on day 4 remained significant (F= 5.84, P= 0.001).
  
  
  CONCLUSIONS
  The current study finds in healthy fetuses a transient, significant and unexplained decrease in fetal middle cerebral artery impedance on the fourth day following maternal dexamethasone administration. Further basic research and clinical studies including larger sample sizes or pregnancies with fetoplacental dysfunction are needed.
authors.affiliation: Department of Obstetrics and Gynaecology, Robert Ballanger Hospital, Aulnay-sous-Bois, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Chitrit
authors.forename: P
authors.initials: P
authors.lastname: Caubel
authors.forename: R
authors.initials: R
authors.lastname: Herrero
authors.forename: A L
authors.initials: AL
authors.lastname: Schwinte
authors.forename: D
authors.initials: D
authors.lastname: Guillaumin
authors.forename: M C
authors.initials: MC
authors.lastname: Boulanger
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D003907:Dexamethasone / Q000494:pharmacology*; D005260:Female; D005602:France; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D008431:Maternal-Fetal Exchange; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000187:drug effects*; D011247:Pregnancy; D012044:Regression Analysis; D016216:Ultrasonography, Prenatal / Q000187:drug effects*; D014469:Umbilical Arteries / Q000000981:diagnostic imaging / Q000187:drug effects*
chemical_list: D005938:Glucocorticoids; D003907:Dexamethasone