<p>Age at first birth has increased over time, which is likely to create many benefits in the labour market. Applying a number of alternative estimation approaches to administrative data from Austria, we estimate small to moderate effects of delaying motherhood on earnings, employment, and attachment to pre-birth firms in the medium run. However, even the largest of these effects are small relative to the average age effects, implying that delay leads to only small changes in child penalties. Much of the career return to later first birth comes from delaying the child penalty rather than changing how careers respond to children.</p>