Stewart D Friedman, a Wharton management professor, recently wrote a new (slightly creepy) book titled Baby Bust. According to a recent Forbes article, the book's focus is how in the past 20 years, the percentage of undergrads who planned to have children has declined by half.
observing stalking Wharton undergrads since 1992, Friedman was able to find that 78% of them expressed interest in having children. Following up with them in 2012, only 42% of them did.
Friedman highlights in his book that this trend is due to many "Millennials" now wanting to focus on their career goals and planning their lives without children in the picture. Looks like Friedman read a bit of this article before publishing his book. No ring, no baby, no problem.