We went to Ethan's 4 month appointment around the beginning of May and he weighed 18lbs. and 26 inches long. His newborn carseat has a 22lb, 29 inch limit so we started to look around for a new car seat to grow with him. Dr. Davis told us that she likes babies to be in rear-facing car seats till they are one year old. I found a great deal on craigslist for a Britax toddler seat that has a 35 lb rear-facing limit and then can be switched to front-facing till 100lbs. They usually sell for well over $200 but I got it for $50! It needed some major cleaning but now it looks great and Ethan really likes it. There's more breathing room and he has lots of room to grow in it.