Background: In Uruguay, the recent phase of fertility decline started in the late 1990s, a decade after deep changes in the family dynamics took root in the country. The order and timing of the two phenomena gave weight to the notion that the changes in the family dynamics caused fertility to drop below population replacement level.

Objective: Our goal is to assess whether or not separation, divorce, and repartnering have been related to the recent decrease in fertility in Uruguay.

Methods: We use data from a retrospective survey and a three-pronged strategy: (1) we compare the contribution to fertility and its evolution across cohorts of three broad steps of the conjugal history; (2) we estimate the effect of each of these steps on the hazard of having the next child; (3) we predict and compare the fertility, actual and counterfactual, of women who ended and women who did not end their first union. We investigate especially how union dissolution affects fertility and how patterns vary by educational levels.

Results: Ending the first union reduces the fertility of Uruguayan women, and this reduction was larger among the low-educated women from the oldest cohort than it is in the youngest one. It could be very small among the highly educated of the youngest cohort.

Contribution: We show that among Uruguayan women, the negative effect of union dissolution on fertility seems to decrease as dissolution becomes more common and occurs earlier, and that changes in family dynamics likely did not cause fertility to drop below population replacement level.