Fetal heart rate decelerations following the administration of meperidine‐promethazine during labor

Abstract

A deceleration response lasting up to 7 min was observed in 53 fetuses (out of 1910 studied) following the administration of 75 mg meperidine and 25 mg promethazine intravenously to the mothers during labor. Thirty-six of these fetuses reacted with baseline tachycardia following the deceleration with or without loss of baseline variability. Seven fetuses showed a variable deceleration pattern and six fetuses reacted with a late deceleration pattern following the first deceleration. Two newborns from the group showing a late deceleration pattern were delivered with an apgar score below 7 in 5 min. The probable mechanisms and significance of these changes are discussed.