Why is there a rise of unwed teenage mothers in church?

I know people make mistakes and abortion is considered immoral by the Christian churches. But, what about what the bible says about sexual immorality, sins of the flesh and fornication? The High School and Young Adult groups at my church have a lot of girls popping them out lately. Is it that they are not listening to our pastor when he speaks of abstinence and keeping our bodies holy? Or, their parents are too lenient, liberal and tolerant? They are getting a lot of attention, smiles and approval nods from their mother's friends and the rest of the congregation. How many 19 year olds who work at Mc Donald's 15 hours a week afford to have and raise a baby? Doesn't seem right somehow.