My immediate reaction to this question is, "That was then. This is now." (I should probably add, "This is the U.S, by the way" (so I'm basing my reply not just on "these days" but also on what's going on in the U.S.". Since I don't think "what I think about mothers" is really the point, and since there's already so much information "out there" about the challenges and disadvantages teen mothers face, I'd rather save my ideas about all that for a Hub (and if I never write a Hub on those there's already tons of information and opinions about there anyway).
As far as studies go, I think many teens don't pay attention to them anyway; but even if some adult manages to get them to pay attention it's generally in the nature of young people to think the "bad stuff" isn't going to happen to them.
In general, I think the right teen mother with the right people/person as part of her "support system", can (with a lot of "if's") find a way to get herself and her child (one child) to an OK-enough place/situation.
The one, kind of insidious, challenge/disadvantage that I don't hear too many people talk about is that the younger someone is when she becomes a mother, the more likely she is to see her child as "all grown-up" when, in fact, that child is still far from grown-up. There are already so many people in our society today who haven't seemed to sort out what's "all grown-up/mature" (intellectually, emotionally, and/or physically") or where any of the lines between any of those things are with each child.
So many people over-estimated children's emotional maturity while under-estimating their intellectual maturity. OR, they interpret increasingly apparent physical maturity as the measure of "grown-up". This isn't just something that goes on with teen mothers toward their own child. In fact, teen mothers are often the products of mothers who, themselves, encouraged or contributed (sometimes by example) their teen daughters to see themselves as "all grown-up" , ready to be a mother and even all prepared to do it right.
The thing too few people talk about is how a twenty-six-year-mother will see her ten-year-old child as "all grown up" (or close to it) while, say, a thirty-six or forty-one-year mother has come to realize how young ten (or three or sixteen or twenty) really is.
I think this continues, or even starts, a chain/cycle that gets harder and harder to break (and brings new and different disadvantages/challenges as time goes on.)