Although it is well established that parenthood affects employment decisions within households, less is known about how this effect varies across couple types in different countries. Using difference-in-differences analysis with propensity score matching and multilevel modeling with cross-level interactions, this study explores heterogeneity in the effect of parenthood on couples' division of paid labor by prebirth relative earning power in different European contexts. The results show that the decline in the female share of couples' paid working hours after parenthood is stronger in male main-earner couples than in equal-earner or female main-earner couples. Our cross-national findings demonstrate that institutional and cultural factors influence couples' postparenthood employment arrangements, with the magnitude of these moderating effects dependent on the couple's prebirth relative earning pattern. Longer paid maternity and family leave for mothers exacerbates the parenthood effect on couples' division of paid labor, whereas greater childcare provision weakens this effect. However, these policy impacts are observed only among male main-earner couples, which can be attributed to differences in opportunity costs and bargaining power across couple types. Egalitarian gender norms weaken the effect of parenthood on the paid labor division between partners regardless of the breadwinner couple type before childbirth.