B660ADT vs G664ADT

My wife is pregnant and due in 2018.  I'm comparing these two Blue Advantage plans (B660ADT vs G664ADT) and wanted to see pros and cons of each.  I know all the Physicians we want are in the HMO so that is not an issue at all.  I was told that I should expect to meet the max out of pocket for my wife's pregnancy.  What else should I be looking at besides the annual premium, family deductible and max out of pocket for the family?  Thanks.