If we want to get into statistics, here we go:
I can guess that 99% of women who purposely become pregnant and then miscarry will be traumatized afterwards.
I can guess that 20-25% of women who accidentally become pregnant and then abort will be traumatized afterwards.
I say this because there are indeed women who do become upset after their abortion. These are the women who are forced into it, guilted into it, or who just didn't know if abortion was the right answer for them. It happens. It's not often, but it does.
However, I think basically every single woman who miscarries a wanted pregnancy is going to be extremely upset for a lot longer than a woman who aborts and is OK with the decision.
So in the end, I feel more women are traumatized by miscarriage than by abortion.