title: Phenytoin and magnesium sulfate effects on fetal heart rate tracings assessed by computer analysis.
abstract: OBJECTIVE
  To compare the effects of maternally administered phenytoin and magnesium sulfate on the fetal heart rate (FHR) using computer analysis.
  
  
  METHODS
  Thirty-six nonlaboring preeclamptic women between 27-41 weeks' gestation were treated with either phenytoin or magnesium sulfate in a nonrandomized fashion. All fetuses were deemed to be well by traditional electronic-biophysical criteria. One-hour FHR recordings were analyzed by computer analysis before treatment. No other medications were administered. Tracings recorded 1 hour after drug administration were analyzed. Therapeutic serum levels were achieved in both groups before FHR tracings were reevaluated. Statistical analysis used paired Student t test, with significance set at P < or = .05.
  
  
  RESULTS
  There were no differences in birth weight, gestational age, Apgar scores, or computer-analyzed FHR characteristics between the groups before treatment. Magnesium sulfate reduced significantly the frequency of accelerations of ten and 15 beats per minute; caused a 62% reduction in reactivity, defined as accelerations of 15 beats per minute in 20 minutes of FHR tracing (but no change in reactivity with accelerations of ten beats per minute); and reduced short- and long-term variability. Phenytoin reduced short-term variability only.
  
  
  CONCLUSIONS
  Phenytoin does not confound the computer analysis of FHR tracings and may offer some advantage over magnesium sulfate when used for prophylaxis against eclampsia.
authors.affiliation: Department of Obstetrics and Gynecology, Newark Beth Israel Medical Center, New Jersey.
authors.forename: E R
authors.initials: ER
authors.lastname: Guzman
authors.forename: M
authors.initials: M
authors.lastname: Conley
authors.forename: R
authors.initials: R
authors.lastname: Stewart
authors.forename: J
authors.initials: J
authors.lastname: Ivan
authors.forename: M
authors.initials: M
authors.lastname: Pitter
authors.forename: K
authors.initials: K
authors.lastname: Kappy
mesh_terms: D003936:Diagnosis, Computer-Assisted; D005260:Female; D006340:Heart Rate, Fetal / Q000187:drug effects*; D006801:Humans; D008278:Magnesium Sulfate / Q000494:pharmacology* / Q000627:therapeutic use; D010672:Phenytoin / Q000494:pharmacology* / Q000627:therapeutic use; D011225:Pre-Eclampsia / Q000188:drug therapy; D011247:Pregnancy
chemical_list: D010672:Phenytoin; D008278:Magnesium Sulfate