Many countries offer new parents long periods of paid leave. Proponents argue that parental leave programs can reduce gender gaps in the labor market, support marital stability and promote children's well-being. In this paper, I show that lengthy leaves can instead work against several of these intended goals. Using a regression discontinuity design, I find that a 3-year expansion of paid leave in France increases household specialization by inducing mothers to exit the labor force and fathers to raise their work hours. The leave further discourages marriages among cohabiting couples and harms children's verbal development.