I was intrigued by a recent study that showed that teenage pregnancy rates in the U.S. are down, in part because of — drum roll — MTV reality shows.

The National Bureau of Economic Research correlated the number of adolescent mothers with Nielsen ratings for “Pregnant at 16,” and “Teen Mom.” Geographic areas with high viewership showed a decline in pregnancies after the series began. The study also examined social media trends, and found comments and searches about contraception rose when new episodes aired.

The dream of having a baby when you’re not much more than a child yourself loses its appeal when exciting sagas of midnight diaper changes and Saturday nights spent alone with a squalling newborn are depicted in living color.

I’ve often contemplated why contemporary teenage girls allow themselves to get pregnant. It’s not like it was in my mother’s day. When she began her menstrual cycle in the 1930s, she almost fainted. Neither her mother nor her three older sisters had told her exactly what to expect. Not surprisingly, women of her generation could, and did, conceive without understanding how it happened.

Although sex education had yet to arrive in full force in public schools when I came of age in the early 1970s, I already had been introduced to some of the biological realities of womanhood in the fifth grade. We girls were herded into the school basement to view a short film and receive informative booklets and sample products.

This opened the door to frank discussions on the playground. Since we were in the Age of Aquarius, it was easy to pick up essential information through the media. Although “The Pill” would not be routinely prescribed to teenage girls until years later, it was out there and in the news. As shy and modest as I was, I knew for a fact that babies were not delivered by storks.

Young adult “problem novels” also made their debut during this time. I loved to read them, as they gave me a chance to vicariously run away from home, meet hippies and, yes, get pregnant.

One of my favorites was “Mr. and Mrs. Bo Jo Jones,” by Ann Head. I read it several times, as a cautionary tale, although the most incomprehensible thing to me was why any girl would get involved with somebody named “Bo Jo.”

Some of my classmates in high school and college did have babies; not many, but it did happen. Contraception then was not what it is now, though, so mistakes were much easier to make.

Which brings us to the essential question: If teenage girls know how babies are made and have access to contraception, why do they still get pregnant?

The answer, for most, I think, is that it’s a lifestyle choice. Yes, contraception is not 100 percent foolproof. But, after 23 years of working with adolescents in public schools, I can report that it is rare to see a middle-class, motivated, involved, ambitious girl have a child during her middle school (yes, it happens) or high school years.

Notice I don’t say “intelligent.” I think of the teenage mom-to-be who, in middle school, spent hours with me in the school library, reading book after book. But she lived in generational poverty, and saw no future for herself except by having babies and living off benefits.

Another girl I know (not through work) was bullied, and dropped out of school. The steps to starting a new life can be daunting: get a license so you can get a job (if you have access to a car), and earn a GED. It can all fall apart if you can’t get to work or night school. When you feel badly about yourself, it’s easy to fall prey to the promise of love — not just once, but three times, with three different men.

It used to be fine, even for the early baby boomers, to aspire to motherhood as a career choice. Some girls nowadays, I sincerely believe, want nothing more. But times have changed. Motherhood is not a career unless you’re old enough to know what you’re doing, married, or in a very committed relationship. Your significant other has to have a well-paying job. You have to remember that motherhood is only a temporary full-time occupation. What will you do if your wage earner dies or takes off? What skills do you have to support your family?

My generation fought to give women options outside the home because most women want to succeed on their own terms, and all women need to be able to. But somehow, we’ve left some girls behind, and they think they only have one option.

Unfortunately for them, it’s the worst one possible — a lifetime of poverty and unfulfilled dreams. It’s a positive that “Teen Mom” is showing this truth, but our real work is getting these lost girls a road map to a better future.

Liz Soares welcomes e-mail at lsoares@gwi.net.