Background: The historical transition towards low fertility in many Western countries was interrupted during the period around the 1950s and ‘60s, called the Baby Boom. This upturn in fertility was completely unanticipated. One of the reasons for expecting continued fertility decline rather than fertility recovery was the expansion of female participation in higher education.

Objective: This research investigates how the recovery of fertility and declining ages at first birth observed during the Baby Boom era can be reconciled with the expansion of female participation in education. How did the pre-existing negative educational gradient in fertility evolve in the cohorts that produced the Baby Boom?

Methods: Using Belgian 1981 Census data, I estimate retrospective measures of cohort fertility. Potential sources of bias in the retrospective data are discussed. Trends in timing and quantum components are charted by women’s levels of educational attainment for cohorts born between 1901 and 1940. A counterfactual simulation is used to delineate the role played by the changing educational gradient in completed fertility.

Results: The recovery of fertility was pervasive in Belgium, but there was a clear convergence between educational groups in terms of the quantum of fertility. Both low and high parity births increased: childlessness declined particularly among the highly educated while the share of women with three or more births went up in all educational groups, but most sharply among the highly educated. The educational gradient in completed fertility was strongly reduced. Without this shift, the recovery of completed fertility would have been about 25% less than its actual magnitude. The educational gradient for age at first birth remained stable: ages at first childbirth declined across all levels of educational attainment.

Conclusions: Convergence in the quantum of fertility across educational groups suggests a major weakening of the role incompatibility between obtaining a degree in higher education on the one hand and subsequently getting married and having children on the other hand. Declining ages at first marriage and childbirth indicate that this period was generally conducive to family formation. The reduction in the educational gradient was a crucial ingredient of the emergence of today’s fertility patterns.