A new article on LiveScience.com talks about higher teen birth rates among teens in communities that are "highly religious". Highly religious is their term, but what they are referring to, is areas with a high concentration of fundamentalist Xians. The article speculates about possible causes for the religious-preggers-ratio, but I have personal experience that strongly suggests that the main problem is ignorance.
In the distant past (1970), when I was a high school sophomore, my family moved from Danbury, Connecticut, which had one of the highest rated and most progressive public school systems at that time, to Avon, Indiana, that didn't. Danbury benefited from the sophistication spillover from New York City and as a result its High School health classes spent a great deal of time on human reproduction and contraception. Avon was a largely rural community that was just starting to become a bedroom community for Indianapolis and evangelical Xians who lived on farms were what the faculty still perceived as the student population. I don't remember health class in Avon, but I remember that many of the councilors and teachers seemed uncomfortable acknowledging that students had two sexes. The attitude of the educators was that ignorance was the best and only condoned contraceptive.
It was easy to see the effect of the different educational approaches: the "highly religious" community had a lot more teen pregnancies. Ignorance is one of the main objectives of fundamentalists. Since they insist that their members must believe the fundamentals of their group, the survival of the group is dependent on their ability to suppress or disavow any contradictory evidence. In addition to that, sex is icky and dirty and embarrassing to talk about so it's best to conceal the facts and hope the kids don't try to figure out what genitalia are for until after they're married.
Unfortunately, in spite of all the parents' prayers, or, according to fundies, because prayer is not allowed in school, hormones beat out ignorance when adolescents feel the need to insure the fitness of the human species. The result is a bunch of undereducated, emotionally unprepared children trying to raise younger children whose existence is frequently resented by the parents. The expectation would be a higher rate of sexually transmitted disease, more abandoned and abused children and more botched abortions. It seems like an awfully high price to pay for religious dogma.