The US fertility rate continued its decline to historic lows, driven by two converging forces: plunging teen pregnancies and a sharp increase in women delaying motherhood into their 30s and 40s. The data, released this week, confirms a structural shift rather than a cyclical dip.

Teen pregnancy rates have been falling for decades — that part is a success story, driven by better access to contraception and changing social norms. The delayed motherhood trend is more complicated. It reflects education, labor market dynamics, housing costs, and a general calculus that the conditions for child-rearing are arriving later in life, if at all.