Do helicopters fly the same instrument approaches as fixed-wing aircraft?
Helicopters can fly the same standard IAPS.  The visibility minimum is the greater of

a) one half the Category A visibility minima, 

b) 1/4 statute mile visibility, or 

c) 1200 RVR


We use Category A's MDA/DH. See the AIM 10-1-2 for more information.

Also there are Copter IAPs (example here), and the viz/altitude minimums are stated on those plates.