Final answer:
A nurse should assess a pregnant client's deep tendon reflexes most importantly if the client has an elevated blood pressure to check for signs of pre-eclampsia.
Step-by-step explanation:
It is most important for the nurse to assess a pregnant client's deep tendon reflexes (DTRs) d. If the client has an elevated blood pressure. This is because heightened reflexes can be an indicator of pre-eclampsia, a serious condition that occurs during pregnancy and can affect both the mother and the unborn baby. An elevated blood pressure may suggest the need for further investigation into possible pre-eclampsia, and the assessment of DTRs can provide additional information to guide diagnosis and management.