Halle Berry Olivier Martinez dinner Beverly Hills pregnant

Halle Berry and hubby Olivier Martinez welcomed a baby boy Saturday ... and X17 snapped the last pix of mom before giving birth!

We spotted the happy couple out last night at Rivabella Ristourante in West Hollywood.

It's the second child for Halle and the first for the French actor. The couple married in France in July.

The baby was born at Cedars Sinai Medical Center in LA; he joins half-sister Nahla, 5.

"Olivier hasn't left Halle's side. Nahla visited her baby brother earlier today," a source tells People magazine.