title: Changes in fetal hemodynamics with ritodrine tocolysis.
abstract: OBJECTIVE
  To evaluate the effect of ritodrine on the fetal cardiovascular system.
  
  
  METHODS
  Cardiac and extracardiac Doppler waveforms were recorded in 12 fetuses prior to and during ritodrine therapy used for preterm labor. Maternal and fetal heart rates, the Doppler pulsatility indices of the umbilical artery, middle cerebral artery, descending thoracic aorta and renal artery, and time velocity integrals of the atrioventricular valves and the ductus arteriosus, were measured.
  
  
  RESULTS
  Ritodrine infusion caused an increase in maternal and fetal heart rates, the left cardiac output as measured by the product of time velocity integral and heart rate, and the pulsatility index of the middle cerebral artery, and a decrease in the pulsatility index of the umbilical artery.
  
  
  CONCLUSIONS
  Ritodrine infusion may alter placental and cerebral blood flow and may have a selective effect on the left side of the heart.
authors.affiliation: Division of Maternal Fetal Medicine, Dr Zekai Tahir Burak Women's Hospital, Ankara, Turkey.
authors.forename: Z
authors.initials: Z
authors.lastname: Gokay
authors.forename: T
authors.initials: T
authors.lastname: Ozcan
authors.forename: J A
authors.initials: JA
authors.lastname: Copel
mesh_terms: D002302:Cardiac Output / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects* / Q000196:embryology; D002560:Cerebrovascular Circulation / Q000187:drug effects; D005260:Female; D005333:Fetus / Q000187:drug effects / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D010920:Placenta / Q000098:blood supply; D011247:Pregnancy; D012039:Regional Blood Flow / Q000187:drug effects; D012312:Ritodrine / Q000494:pharmacology*; D013566:Sympathomimetics / Q000494:pharmacology*; D015149:Tocolytic Agents / Q000494:pharmacology*
chemical_list: D013566:Sympathomimetics; D015149:Tocolytic Agents; D012312:Ritodrine