[ternnoburn]

So? Are you worried that baby is going to go out and try to score baby heroin? You have to point to some actual negative outcome beyond "the drugs we gave were present".

Why don't mothers with the most children use painkillers?

Having children fundamentally alters your body, making future births easier, generally. The people with the most children tend to be poorerto, and might not be able to afford painkillers. The people with the most children might be religious families who treat women as machines for producing children. Maybe about a million hypotheses.

But we should be studying it! You are right about that. Our health care system under studies the experiences of women.