Final answer:
Late decelerations in fetal heart rate are a serious indicator of placental insufficiency and could lead to fetal distress, requiring urgent medical attention.
Step-by-step explanation:
A pregnant client at 35 weeks gestation is admitted to the birthing unit with preterm labor. The assessment that would require the nurse to immediately notify the provider is: a) FHR 120 b/min with late decelerations, contractions- every 1-2 minutes. Late decelerations are associated with placental insufficiency, which can lead to fetal hypoxemia. This can be an indication of fetal distress, and immediate medical intervention may be necessary to ensure the wellbeing of both mother and baby.