A bee can carry a bit over its own weight, 1/10 of a gram.
An human newborn is 3.5 kg, so that would take 35000 bees. The problem is that 35000 bees would not be able to reach and grab hold, and would interfere with one another if you could somehow get them to reach.
Now, about over sizing bees,forget about it. Any object scales in weight with the cube of their length, but in area only with the square. So a bee that is twice as long would weight 8 times more but would have wings that are only 4 times the area.
An insect 8 times the weight of a bee needs wings that are proportionally 40% longer and wider than those of a bee.
Also, bees (like all insects) do not have lungs, they breathe through little holes in their exoskeleton (tracheae), and the oxygen has to diffuse though their body. This system is effective from small creatures only and cannot work for insects past a fairly light weight (heaviest confirmed weight for insect is 71 g, and was a female full of eggs anyway).