When I saw the title and first line of this post I thought you'd be complaining that the child doesn't sleep, and I was going to reassure you that it will come to an end; he/she will sleep through the night eventually and all will be fine.
Please be grateful that that isn't a problem.
If there are other signs that he/she (we still don't know its gender, even) is not engaging with the world there might cause for worry, but from what you say there doesn't seem to be.