There is a fundamental flaw in your premises, which is that it is immoral to inflict suffering. One might make a good case that it is immoral to intentionally
inflict suffering--but a claim that inflicting suffering is, in and of itself, immoral, won't stand up to scrutiny. If you unknowingly step on an insect without killing said insect, would you be immoral for inflicting suffering? If you were with a group of friends in a public place and ridiculed the outfit that someone were wearing, while, unknown to you, someone wearing that same outfit stood behind you, would you be guilty of moral turpitude because they suffered shame or embarrassment?
I have to wonder what your personal background is for you to make such a claim about bearing children. It seems that you might have some anger or resentment--i don't know, of course. Neither people nor life is as simple, or as cut and dried, as your thesis seems to suggest. People have children for many reasons, some which might be thought bad, some which might be thought good. I know of many families in which the members are happy and loving, and care for one another. Have any members of that family ever suffered? Of course they have. The bible tells us: Yet man is born unto trouble, as the sparks fly upward.
(I'm not religious and mean no religious implications in quoting that--it is foolish not to recognize wisdom wherever one finds it.) Suffering is a part of life just as is joy.
Which leads us to the other major flaw in your premises. Do people want to end their lives because of suffering--perhaps, but i doubt that that attitude is very common. You could take a good lesson from dogs. Earlier i mentioned inflicting unintentional suffering by unknowingly inflicting suffering by stepping on an insect. But what about unknowingly hitting a dog while you're driving? I've known several three-legged dogs, including one who had the normal equipment, but who lost one leg when she was struck by a bus. Would she have rather died than suffer as she did? Don't you believe it. Within days she had adjusted to her injury and she was a lively and happy dog who loved her human and canine friends and who got as much joy out of life as possible.
I strongly suggest that you re-evaluate your premises and spend some more time thinking about suffering. Now, if you'll excuse me, one of our little rescue dogs just came downstairs looking for some love, and i'm happy to give it to her.