There's a better question that is rarely - if ever - asked in such discussions, and it is, why does Western society place such a dark and bitter cloud over what is a natural, instinctive urge and a natural process?
One could argue that there is a practical issue of how a baby born to young people with fewer means can become a greater burden on society. However, I personally believe that argument stems from the same piss-poor attitude that created the notion that sex is evil in the first place.
I'm not saying children aren't a big responsibility. They are. I am a dad. I know. What I am saying, from the point of view of someone who was born to a young mother, is that society's animosity toward young mothers and their children, and fear of sex, are the real problem. It's a back-assward attitude based on Puritan spite, and it doesn't help anything.
My mother was three days from seventeen when she had me. She worked hard to support me. I turned out a good kid. The hardest thing about it, and the biggest evil of the whole situation, was the outright hatred we were subjected to, from supposed "good Christians" just frothing at the mouth for a chance to judge and punish my mother, and myself by extension, by refusing her work, turning her down for credit, badmouthing her on the bus, snickering at her, shouting at her, and outright trying to take advantage of us both.
Having babies young can be an inconvenience, and even a hardship, but it's hardly an evil. It would be less of an inconvenience and less of a hardship on everyone, if society could get over the stigma of evil and wrongness it has applied to these situations, and just work at being human about it.