> That has me puzzled, too. My first thought is that it's a poor family's best opportunity to get their daughter married off...??
More like they have no hope that their daughter will ever get married, so this is the next best thing. Where I grew up, getting knocked up on prom night was practically a rite of passage for the lower classes.
By the time my daughters grew up, high schools had daycare centers, and provided free baby-sitting on prom night.
My wife teaches high school, and they have a large daycare.
Most kids coming from a single parent household will follow a similar pattern. This is spreading faster than you can believe.