Fetal heart rate decelerations after oxytocin infusion in an abdominal pregnancy.

Fetal heart rate (FHR) decelerations during a contraction stress test are recognized as signs of possible uteroplacental insufficiency. Although these decelerations have been described commonly in intrauterine pregnancies, they have not been noted in extrauterine pregnancies. Reported herein are FHR decelerations associated with oxytocin infusion in an extrauterine pregnancy and a discussion of the possible pathophysiologic mechanisms.