I may have poor circulation but I notice that my arms often fall 'asleep' while I'm sleeping. Is there a way to minimize this? It's annoying to keep waking up from pin-needle like arms and move to different positions.

Sounds more. like a nerve compression, rather than poor circulation. Have your doctor check out your neck and other places where nerves to the arm could become compressed.
Pins and needles. Do not think that is circulatory sounds more like nerve compression most likely from neck since it affects both arms.
Positional? Is there a certain position that your arms are in when they fall asleep? are you on your side, on your back with arms behind head? IS there any position that they fall asleep when you are awake? You should think about all this and discuss with a physician.
Neurogenic. cause seems likely. This could be related to sleep posture or nerve compression in neck. Please consult with a neurologist.