I am not sure which approach you were specifically flying and where you were holding though I am assuming that you were completing a published hold in lieu of a procedure turn on the approach.
See AIM 5-4-9(a)(5):
If cleared for the approach prior to returning to the holding fix, and the aircraft is at the prescribed altitude, additional circuits of the holding pattern are not necessary nor expected by ATC. If pilots elect to make additional circuits to lose excessive altitude or to become better established on course, it is their responsibility to so advise ATC upon receipt of their approach clearance.
If you request additional circuits in the hold and ATC approves your request and clears you for the approach, then the approach clearance is still valid while holding at and after leaving the holding fix (unless the approach clearance is specifically cancelled for some reason).