During labor in a patient with autonomic dysreflexia, when does hypertension most commonly occur?

• A. With uterine contractions
• B. Between contractions
• C. Only during sleep
• D. Only postpartum

Answer: (A)

Autonomic dysreflexia is a hazardous overreaction of the autonomic nervous system in people with high-level spinal cord injuries. A noxious or painful stimulus below the level of injury triggers a massive sympathetic response, causing widespread vasoconstriction and a sudden rise in blood pressure. The key is that the trigger is below the injury, so the body’s normal buffering (baroreceptor reflex) can’t adequately suppress it.

During labor, uterine contractions are a potent, recurrent visceral stimulus that repeatedly activate those afferent pathways below the injury. This makes contractions the most common trigger for hypertensive episodes in this setting. Between contractions, the stimulus is reduced, so the spike in blood pressure is less likely. While other times (like postpartum or during sleep) can be associated with triggers, the transient, painful contractions during labor are the typical precipitant of autonomic dysreflexia-induced hypertension.