The first year of your baby’s life is full of change and growth and development. Just when you think you’ve got everything in place, they go ahead and learn a new, fun skill or grow out of every onesie you own.
Just as you will need to transition out of the swaddle, and out of the bassinet, so too will you need to change the height of your cot mattress. This needs to happen for safety reasons.
When your baby is starting to pull themselves up and also trying to sit independently, then that’s the time to do it. Cot safety is incredibly important, and if the cot mattress stays too high then there is risk of injury and your baby pulling themselves up and over the side. Naturally, we want to avoid all unnecessary risks when it comes to safe sleep. You are welcome to have the cot mattress at its lowest setting with your newborn, but you may find that with so many naps, feeds and re-settling sessions that your back needs a break.
The exact timing of when you need to lower the mattress height depends greatly on your own baby’s growth and development, but it’s generally between 5 – 8 months of age. I put O’s mattress down at about 6-7 months when he started trying to pull himself up on the side of the cot. He still does it even at the lower height, but not at least he’s safe to do so.