I had my child at 41 (I'm the mother), and I see none of these issues, and my son has been over 10kg for quite some months now. My early-30s colleague on the other hand complained of back pain already in her pregnancy.

Age is not the death sentence you seem to think it is; on the contrary, if someone in early 40s doesn't have the energy/fitness to handle a child, they should see a doctor.

(I also got pregnant within a couple of months of trying, as did a neighbour of similar age. Personal biology trumps statistics.)