Following the arrival of the first child, women's absence rates soar and become less predictable. This fall in workplace presenteeism harms women's wages, especially in jobs with low substitutability. Although both presenteeism and job uniqueness are rewarded, we document that women's likelihood of holding jobs with low substitutability decreases relative to men's after childbearing. This gap persists, with important long-run wage implications. We highlight that the parenthood wage penalty for women could be reduced by organizing work so that more employees have tasks that can be performed satisfactorily by other employees in the workplace.