Fertility postponement and increases in life expectancy have contributed to changes in parenthood expectancy (PEX), i.e., the time people can expect to live as an ever-parent. While previous work showed gender and country differences in PEX, nothing is known about age-specific contributions to changes in PEX. We fill this gap by using data from the Human Fertility Database (HFD) and the Human Mortality Database (HMD), and applying decomposition analysis based on a stepwise replacement algorithm. We find that age-specific positive contributions to changes in PEX between 1970 and 2019 mostly derive from the life-expectancy component. Focusing on reproductive ages (15–49), we observe that losses in PEX due to the fertility component conceal some of those gains. This does not hold at very late reproductive ages, though. Understanding these age-patterns can inform us on the specific sub-populations contributing to changes in the indicator over time, which then can have applications in individual-level analyses.