Abortion is a way to avoid a hazard living space for a child and a way to avoid a traumatizing event for the mother. Some people get too many abortions and that should not happen, but a lot of women need the option to abort because they are not ready to be a parent or had gone through a terrible experience that resulted with pregnancy.
Abortion would do more than just avoid hazards for children, it would avoid every good thing, too. While the question wasn't clear, I'm assuming that the hazards mentioned are beyond things like small pieces of toys or uncovered power outlets. What I'm considering hazards or potentials for diseases like cystic fibrosis, diabetes, epilepsy, etc. However, research on these diseases continues to return results. Diabetes is very manageable, with certain research results showing a possible cure sometime in the next couple of decades. I've know many people with all of those diseases and they lived full, very happy lives. Abortion to avoid a possibility of having a disease robs the certainty of experiencing the joys of life.