  An assessment is made of recent attempts to evaluate how quantum gravity may
affect the anisotropy spectrum of the cosmic microwave background. A
perturbative scheme for the solution of the Wheeler-DeWitt equation has been
found to allow for enhancement of power at large scales, whereas the
alternative predicts a suppression of power at large scales. Both effects are
corrections which, although conceptually interesting, turn out to be too small
to be detected. Another scheme relies upon a Born-Oppenheimer analysis: by
using a perturbative approach to the nonlinear ordinary differential equation
obeyed by the two-point function for scalar fluctuations, a new family of power
spectra have been obtained and studied by the authors.
