  We report on the status of primordial nucleosynthesis in light of recent
results on CMB anisotropies from WMAP experiment. Theoretical estimates for
nuclei abundances, along with the corresponding uncertainties, are evaluated
using a new numerical code, where all nuclear rates usually considered have
been updated using the most recent available data. Moreover, additional
processes, neglected in previous calculations, have been included. The combined
analysis of CMB and primordial nucleosynthesis prediction for Deuterium gives
an effective number of relativistic degrees of freedom in good agreement with
the simplest scenario of three non degenerate neutrinos. Our findings seem to
point out possible systematics affecting 4He mass fraction measurements, or the
effect of exotic physics, like a slightly degenerate relic neutrino background.
