This study contributes to the literature on how parenthood affects the within-couple gender earnings gap. It examines how this 'child penalty' on women's earnings varies with the education level of both partners and the woman’s relative education within the couple. Using Austrian register data on 268,156 heterosexual couples who entered parenthood between 1990 and 2007, and an event study design that uses the couple as the unit of analysis, we examine the heterogeneity in the magnitude of the