I always recommend that you cocoon the bedding over your baby rather than stretch it tight.
There are a few reasons for this which I will explain further below.
Why I believe it is better to Cocoon vs Stretch
When stretching the bedding over your baby, there is still space for air between your baby’s sides and the blankets that will make your baby cold.
If a cold baby rolls onto his tummy and then slips down under the stretched blankets he can get stuck face down.
If your baby happens to slip down under the blankets, the blankets might be too tight to free himself.
Instead, I recommend the cocooning technique. You lay your baby at the foot of the cot, with any excess sleep bag tucked under your baby. Then place the blankets over your baby (ensuring his face is not covered), tuck in the blankets at the foot of the cot and then push the blankets in at his sides to make him feel warm, safe and secure.
If your baby rolls onto his tummy, the blankets will move with him, rather than trapping him face down in the mattress. He will be able to lift his head and the blankets up because the blankets are not tucked in tightly at teh sides.
An additional benefit of cocooning is that for an older baby or toddler, if he moves slightly in his sleep, the bedding will move with him, keeping him covered and warm, in return helping to keep him in the safe back sleeping position for as long as possible.
If you think back to when your little one was born, your midwife most likely cocooned him in blankets because hospitals also know cocooning is the safest way to sleep your baby.