Changes in fetoplacental vessel flow velocity waveforms following maternal administration of betamethasone

Ultrasound Obstet Gynecol. 2002 Sep;20(3):240-4. doi: 10.1046/j.1469-0705.2002.00782.x.


Objective: To determine the timing of the onset of the umbilical artery flow velocity waveform changes following maternal administration of betamethasone in pregnancies complicated by umbilical artery absent end-diastolic flow, and to explore whether these changes are associated with flow velocity waveform changes in other fetoplacental vessels.

Subjects and methods: This was a prospective study of 12 women with pregnancies complicated by umbilical artery absent end-diastolic flow. Flow velocity waveforms were recorded from the umbilical artery, fetal middle cerebral artery, renal artery, aorta and ductus venosus, before and after maternal betamethasone administration, using real-time pulsed wave Doppler.

Results: In all 12 pregnancies, the administration of maternal betamethasone was followed by the return of end-diastolic flow within 24 h. End-diastolic flow was first observed at 4 h and was present in all women studied at 8 h. In addition, there was a statistically significant decrease in the pulsatility index in the fetal aorta at 8 h and the middle cerebral artery at 24 h. No change was observed in the ductus venosus or the renal artery flow velocity waveforms.

Conclusion: The findings suggest that, in pregnancies complicated by absent end-diastolic flow in the umbilical artery, maternally administered betamethasone induces a return in umbilical artery end-diastolic flow as early as 4 h, along with widespread vasodilatation throughout the fetoplacental vasculature.

MeSH terms

  • Betamethasone / therapeutic use*
  • Blood Flow Velocity / drug effects*
  • Female
  • Glucocorticoids / therapeutic use*
  • Humans
  • Placental Circulation / drug effects*
  • Pregnancy
  • Prospective Studies
  • Time Factors
  • Umbilical Arteries


  • Glucocorticoids
  • Betamethasone