A gravida 3, para 2 at term requires labor augmentation with a Pitocin (oxytocin) drip. After initiating and titrating the Pitocin (oxytocin) drip for two hours according to hospital protocol, the nurse notes recurrent late decelerations and minimal fetal heart rate variability on the fetal monitor strip. Contractions are every 1-2 minutes lasting 90-100 seconds. What is the first action the nurse should take?