I do not want to know what happens after you have to stop swaddling your baby. Swaddling is the only thing that keeps C asleep all night....the second he breaks out, he startles and hits himself in the face and wakes up crying. Swaddling has been a lifesaver for us, and we've tried our fair share of swaddling-related products!
Don't get me wrong...I LOVE these Aden + Anais muslin swaddle blankets. They are the perfect lightweight material, and I always have one in my diaper bag - they are perfect for laying on the ground when you're out in public and want to let the baby play, and they are great for providing a little extra warmth in the carseat or stroller. However, I don't recommend them for actual swaddling purposes. These require learning an actual swaddling method, which is extra effort in the middle of the night, especially since C ALWAYS broke out of these when he was swaddled in them. I think it's because the muslin fabric has a little "give", which is not what you want to keep your baby swaddled tight! In summary: still buy them, but not for swaddling.
Better: Halo Sleepsack Swaddle
Our hospital gave us one of these at our childbirth class, so that seemed like a pretty strong recommendation. It's essentially a sleeveless sleepsack; stick your baby's arms through the arm holes, zip it up, and then use the two swaddle "flaps", which velcro, to swaddle baby's arms. This one was great in theory, and it worked for about the first 2 weeks....and then C got too strong and broke out of this swaddle every. single. time. The fabric is pretty stretchy, so he was able to loosen it up and get his arms out. Not good!
These are the holy grail of swaddling products! They're similar in concept to the Halo Sleepsack Swaddle, except there's no zipper or armholes involved. Put your baby's legs in the pouch part, and then use the two swaddle "flaps" to velcro baby's arms securely by his side. These wraps are made from cotton that only has a slight stretch to it; C had a much harder time breaking out of these. We used the small size for the first month, then upgraded to the medium/large size, which we still use today at 3.5 months.