While I agree that the reasons you mentioned are terribly trivial for ending a life, I also would caution you to consider the true complexity of the situation which extends to much further depths than the "legs shut" argument. Imagine expecting your first child and being informed that if he/she is lucky enough to survive pregnancy he/she will die an excruxiatingly painful death or be forced to live a life worse than your darkest fears. Nature is cruel. And yes, this happens even to planned children with mothers who do not abuse substances.