Final answer:
Pain in the left calf with dorsiflexion of the left foot in a woman who is 12 hours postpartum is concerning for deep vein thrombosis (DVT), a potentially life-threatening condition.
Step-by-step explanation:
A finding that would be a source of concern if noted during the assessment of a woman who is 12 hours postpartum is D. Pain in left calf with dorsiflexion of left foot. This could be indicative of deep vein thrombosis (DVT), a condition that is potentially life-threatening and requires immediate medical attention. Postpartum women are at an increased risk for blood clots, and symptoms such as calf pain with dorsiflexion, also known as Homan's sign, are particularly concerning. While postural hypotension, a slight temperature elevation, and bradycardia can occur in the postpartum period, they are generally not as concerning as the potential for DVT.