Wood has already scored one goal in four appearances for the Blues.
Birmingham boss Chris Hughton told the club’s official website: “Chris is someone who has got better in the period of time he has been with us. Being in and around the team and getting games under his belt has done him a world of good.
“At this moment we have also got Marlon King who is very close to a return after working hard in training and Nikola Zigic who will be back in full training after the international break, so things are looking up.
“I’m delighted we’ve got Chris for a longer period and with the players who have been injured on the way back we can get back into a situation where we have competition for places up front, and that can only be good.”
