I doubt that teens are abstaining in the classic sense more. What seems to be happening is that there is a lot more oral sex happening, and perhaps more buggery as well. Blow jobs, cunnilingus, Sixty-nining, and cornholery are all practices that do not cause pregnancy.
Teens now have cellphones, which means that there is more sexting going on. The shaving of pubic hair, especially among girls and women is becoming the in style, because it is far more photogenic. It also makes cunnilingus more pleasurable.
Not the sort of thing I would think that a bluenose like Mike Pence would be up on.