With my first. I had her on a boppy pillow because having a baby sleep flat on thier back can cause the back of thier head to become flat. but by time she was 4-6 wks old she would only sleep on her stomache with her butt in the air. Im 39wks 2days with my second and I plan on trying the boppy trick again.
You are supposed to have them on there back but some babies will not. It also depends on what you doctor says. Babies with acid reflex sleep better on their left side and it decreases the risk of them breathing the acidic stomach contents. You can also place blankets under the head of the bassinet matress to elevate them. Premies may require to sleep on their tummies to assist them with breathing because their lungs aren't fully developed. It was your doctor suggests.
You're suppose to put baby on their back if you're not around or paying attention. Unfortunately sometimes my 2 month old will not at all sleep any other way but on his stomach. The second he's one his back he will wake up it just depends on his mood.
At first my son mostly slept on his side as I would feed him laying down because I was in so much pain due to my stitches, but now if I lay him on his side he'll just role over onto his back. Like the lady above me said, it's whatever position they're comfortable in.
My son is almost 10 weeks and hates being in any other position other than on his back,he'll throw his arms around until he comfortable to sleep properly.
Also a week after he was born he caught a cold from me so laying him on his side helped him breath easier. :)
My daughter sleeps on her tummy. Has since she was 4 weeks old. That's literally the only way she would sleep and still does at 8 months old. At 4 weeks old, she was able to lift her head and move it from side to side. She had gas issues so putting her on her tummy helped her get the trapped gas out. Her pediatrician said it was perfectly fine. Baby will sleep how they're comfortable. Babies can be tummy sleepers, side sleepers or back sleepers. I suggest first try setting them on their back. Don't be afraid to try putting baby on their tummy though.
Always place an infant on their back with nothing in the crib (no excess blankets, stuffed animals, pillows, ect) and if you put a blanket with them either swaddle them in it or tuck the blanket in on 3 sides to ensure they won't suffocate with the blanket. Remember ABC- Alone on their Back in a Crib. :) I work in child care and had to take safe sleeping courses.
On the back. If you put them on their side, they can roll over and suffocate because they can't move their head to the side to breathe. However, you can always ask the nurse when you deliver
put my baby on his back. :>)