The three-week-old's umbilical cord wrapped itself twice around his neck, almost strangling the child and slowing his heart rate dramatically.
But the MAGGIE MAY hitmaker is keen to praise medical staff for their speedy actions, which saved his son's life.
He says, "The doctors were unbelievably quick. Without cutting the cord, they managed to get it over the baby's head in a second. So skilful."
Lancaster adds, "It was frightening. The poor little thing."