Did you make case specific inquiry? , if not make one with all the updated documents baby birth records, communication logs remittances travel documentation if you traveled. it helps them make the decision faster once they review the file. Make the inquiry and you can also order notes as well as that if no response.
And i would say they are tying to do cases within the time frame but its hard to predict. i know a friend of mine who's wife case was done in 7 months 100% because i filled the documents feb 2013 and his wife is here already. he had a child i think having a child based on my experience makes the case very strong.