B.C.
Well, for newborns they give them a hot foot (warm pad on a foot), and then prick the heel for a few drops of blood.
An experienced nurse can do this and the baby won't even cry.
For a week or so after our son was born they tested him daily for bilirubin and as a new mom - hearing my baby cry (we had a trainee nurse for a few days) made me want to punch somebody.
I don't know how much blood they have to draw but at 15 months old - you absolutely can hold them still on your lap while they do it.
You have muscles and they don't.
Our son had pneumonia at 14 months and I had a hold where I pinned him down on the floor (towel under him) in order to get his medicine down his throat.
It wasn't easy but the doctor said that being diligent with the medicine really helped keep our son well enough so he didn't land in the hospital in an oxygen tent.
You do what you have to do keep your kid alive and " I can't " gets dropped from your vocabulary.