Antenatal corticosteroid therapy: a comparative study of dexamethasone and betamethasone effects on fetal Doppler flow velocity waveforms

Eur J Obstet Gynecol Reprod Biol. 2005 Jun 1;120(2):170-4. doi: 10.1016/j.ejogrb.2004.09.009.


Objective: To compare the effects of antenatal administration of dexamethasone and betamethasone, used in two different regimens, on fetal Doppler flow velocities.

Study design: Sixty-seven women at risk for preterm delivery received course of corticosteroids by means of a computer-generated randomization table. The Doppler examination of the pulsatility index (PI) of the umbilical artery (UA), the middle cerebral artery (MCA) and the middle cerebral artery/umbilical artery PI ratio (MCA PI/UA PI) were performed before treatment, 24 and 72 h after the first dose of corticosteroids. The SAS system was used to perform statistical analysis.

Results: No significant change was observed in UA PI through dexamethasone therapy. In MCA there was a significant decrease in PI at 72 h (2+/-0.43 before and 1.68+/-0.31 after, p=0.0001). Similarly a significant decrease in MCA PI/UA PI ratio was noted (2.09+/-0.51 before and 1.83+/-0.4 after, p=0.0137). No significant changes were observed in UA PI, MCA PI and MCA PI/UA PI ratio during betamethasone treatment.

Conclusions: Our results indicate significant decrease in fetal middle cerebral artery impedance at 72 h after maternal administration of the first dose of dexamethasone. Effects of dexamethasone on fetal brain warrants further research.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Betamethasone / administration & dosage*
  • Dexamethasone / administration & dosage*
  • Female
  • Gestational Age
  • Glucocorticoids / administration & dosage*
  • Humans
  • Laser-Doppler Flowmetry
  • Middle Cerebral Artery / physiology
  • Obstetric Labor, Premature
  • Pregnancy
  • Pulsatile Flow
  • Risk Factors
  • Umbilical Arteries / physiology


  • Glucocorticoids
  • Dexamethasone
  • Betamethasone