Maternal and fetal cardiovascular indices during fetal hypoxia due to cord compression in chronically cannulated sheep: II. Responses to promazine

Abstract

Promazine (Sparine) administered to chronically cannulated pregnant ewes caused significant maternal and fetal tachycardia and hypotension, depressed uterine blood flow and fetal PaO2, and increased fetal PaCO2. When the drug was given before brief compression of the umbilical cord, uterine flow was more depressed than by compression alone, the fetal pressor response was attenuated, and fetal posthypoxia tachycardia was augmented. We conclude that promazine taken by a mother could have especially deleterious effects on her fetus when the latter's oxygenation is already depressed (e.g., by cord compression), and suggest that the use of promazine during labor be reevaluated.