I understand from prior readings that there may also be a lesser increase in those with miscarriages. Seems to be the hormones activated by the pregnancy go a bit haywire when it is not completed, but natural terminations are not as significant as unnatural.
My first child was stillborn at 42 weeks and another child was miscarried at 12 weeks. I had to have a D&C for the miscarriage because the bleeding was so intense, and I asked my doctor if that would jeopardize my health - either with incompetent cervix or breast cancer. He said that it’s a whole different story when the body is going through the natural steps, versus when a doctor DEFIES nature to cause a different outcome.
When a person miscarries, the body knows the child has died and it goes through a tapering-off process with the hormones to end the process naturally. It’s not an abrupt stop to the breast growth/development, so the reproducing breast cells have time to get the “turn off” message from the body. Sort of like an arm swinging around that gradually slows down. Totally different outcome than if an arm is swinging around with a ball in it and stops abruptly. The ball keeps going; it doesn’t have a shut-off mechanism when the hand stops abruptly. So those breast cells continue to reproduce; they don’t have a shut-off mechanism. (Incidentally, this is the same reason that embryotic stem cells that have been used in experiments have caused cancer; the birth process instills the shut-off mechanism for embryotic stem cells. Without that shut-off mechanism those embryotic cells are basically like a cancer - cells that keep reproducing and don’t know when to stop.)
Same thing with the cervix. The cervix wants to stay shut when there’s a live baby inside to protect, but when the child has already died, the body starts the process of letting go. The rods for a D&C don’t have to fight the body after a miscarriage, because the body isn’t fighting to protect the child any more.
That’s what my doctor told me, and what I’ve read seems to support that.