bow legged toddler - grow out of it?

Always something to worry about.

McBaby is VERY bow legged, has been since he started walking at 10 months.

I read that it is common esp at 12-18 months (he's 18 months) but most by 3 years grow out of it. He again is very spead, I can get my fist sideways between his knees when his ankles are touching. He has immunizations in a few weeks and was going to mention to the MD but what I read is they dont do anything for it like they use to (braces/shoes) but leave it be.