A fundamental switch in the fertility—development relationship has occurred so that among highly developed countries, further socioeconomic development may reverse the declining fertility trend. Here we shed light on the mechanisms underlying this reversal by analyzing the links between development and age and cohort patterns of fertility, as well as the role of gender equality. Using data from 1975 to 2008 for over 100 countries, we show that the reversal exists both in a period and a cohort perspective and is mainly driven by increasing older reproductive-age fertility. We also show that the positive impact of development on fertility in high-development countries is conditional on gender equality: countries ranking high in development as measured by health, income, and education but low in gender equality continue to experience declining fertility. Our findings suggest that gender equality is crucial for countries wishing to reap the fertility dividend of high development.