The effect of drugs on fetal heart rate variability

Am J Obstet Gynecol. 1978 Feb 1;130(3):294-9.


Baseline FHR variability has been quantitated into the mathematical indices of differential index (short-term variability) and interval index (long-term variability). Normal values have been determined. The effect that drugs used during labor have on FHR baseline variability has been evaluated. A clinically meaningful change in variability has been observed following low-dose administration of Demerol, morphine, Nisentil, Phenergan, and Vistaril. A statistically significant increase in variability has been observed following administration of magnesium sulfate.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Analgesics, Opioid / pharmacology
  • Female
  • Fetal Heart / drug effects*
  • Heart Rate / drug effects*
  • Humans
  • Hydroxyzine / pharmacology
  • Labor, Obstetric
  • Magnesium Sulfate / pharmacology
  • Pregnancy
  • Promethazine / pharmacology


  • Analgesics, Opioid
  • Hydroxyzine
  • Magnesium Sulfate
  • Promethazine