We study how childbirth increases the likelihood of young, working mothers to claim disability insurance and how paternity leave could ease this effect. Our event study analysis uses Belgian data to show that the incidence rate of disability across gender only diverges after first-time childbirth. This "other child penalty" can be reduced with the provision of paternity leave. Our regression discontinuity difference-in-differences design shows that mothers with partners eligible for a two-week-long paternity leave spent on average 21% fewer days on disability over twelve years. Moreover, we show links between this incidence of paternity leave and consequent birth-spacing decisions.