In my opinion, it's because their parents are "missing in action"
I think it's like Angela said : Lack of parental supervision and teaching. If parents would spend more time with their kids and teaching them family morals and such, there would be a lot less of teen pregnancies.
Actually teen pregnancy rates are down. Through education and making birth control available, there has been a 57% decline of teen pregnancy in the last 20 years.
Well for one thing, teens think that just because their age is 16+ they know the world. So they think they can handle responsibilities like losing their virginity and smoking and doing unspeakable things. But when they get pregnant they break down and do the whole "Woe is me!" speech. Us teens aren't as adult as we may think we are!!
This isn't anything new, it's been going on forever. Teens are exposed to sex a lot earlier due to Internet. It's hard to avoid, we need parent involvement , education, and common sense. Birth control must be available as well.
Bad parents