In 1970 and 1946, it wasn't super uncommon for 17-19 year-old women to be married and starting families. My grandma had my mom when she was 17 (with her husband), and my mom got pregnant with me on her honeymoon (at 19).
A couple of anecdotal examples obviously don't tell the whole story, but I do wonder if the nature of the families created from those teen pregnancies is a little different today than what it was 40-60 years ago. Also, data discussing where the teen pregnancy rate was in relation to the overall birth rate would be useful, since that varies with the economy, major events, etc. (like WWII). If the rate is rising while the overall birth rate is falling, that could be meaningful.