Problem with that argument is that the teen birth rate has dropped steadily since the 1970s.
http://www.childtrendsdatabank.org/indicators/13TeenBirth.cfm
"Birth rates among teen females ages 15 to 19 declined by more than a third between 1991 and 2005, from 61.8 per 1,000 to 40.4 per 1,000. (See Figure 1) Declines since 1991 are also evident for younger girls (ages 10 to 14), decreasing from 1.4 per 1,000 in 1991 to 0.7 per 1,000 in 2005 (based on preliminary estimates). Among teen males, the decline began after a peak of 24.7 per 1000 in the early 1990s, a few years after the adolescent female birth rate began to decline, and was 17.0 per 1,000 males in 2004*. (See Table 1) Declines for non-Hispanic black teens have been particularly large, with the birth rate among teen girls ages 15 to 19 declining from 118.2 per 1,000 in 1991 to 60.9 per 1,000 in 2005 (based on preliminary estimates). (See Figure 1)"
America has become a much safer and civilized place since the 1970s. However, safer and civilized doesn't get much in the way of ratings for the 24 hour news channels, so the newsies do their best to puff up the bad news, even if the bad news is extremely rare.
Go look up the numbers and then watch the televised hysteria that totally disregards what's really going on in the country.