Jonathan Last, writing for The Weekly Standard, notes that fertility rates are falling at precipitous rates worldwide. He notes, for example:
Between 1990 and 2000, every region in the world saw the total fertility rate decline. Among nations with rates above the "replacement rate," only two countries saw a rise in fertility: Suriname and Israel, whose rates increased by 0.17 and 0.01 children per woman, respectively. We see the same trend in nearly every country of every size in every climate and with every conceivable political, religious, and economic system--which suggests a complicated set of factors at work. It raises at least the possibility that the root of the problem may involve modernity itself.
While the factors that contribute to this are complex, he posits that the interaction of a few of them, namely an increase in the number of working women, the diminishing role of children as a labor force, an increase in abortion and women delaying having children until their thirties play critical parts in this process. An interesting article.