I had the same issue with my second daughter, she didn't sleep through the night until after a year! My pediatrician told me she was waking up because she was used to eating in the middle of the night, even though it was not necessary. What I had to do was get her used to not eating in the middle of the night by reducing her bottle by an ounce for a week, then another ounce the next week until there was no bottle. She did cry for about a week or so without it which is not pleasant in the middle of the night, but it did work. After that, she no longer woke to eat. It worked for me, good luck!