Using French administrative data, we investigate the consequences of childbirth on gender inequality in the labor market between 2005 and 2015. We develop a novel approach that allows us to consider how the impact of children varies with labor market opportunities of men and women. While men are almost not affected by the arrival of a child, mothers experience large labor earnings losses that are primarily driven by labor supply decisions at both the intensive and extensive margins. Low-wages women opt out or decrease their working hours more frequently than their higher wages counterparts do. This is likely due to the opportunity cost of career interruptions, in line with incentives created by the French family insurance system. Consistent with this heterogeneous specialization towards family and the labor market, both low-wages and high achieving mothers face hourly wages penalties with respect to fathers, albeit with a different timing. As a result, the arrival of a child contributes to both glass ceilings and sticky floors patterns that are common among developed countries.