A growing body of evidence suggests that reproductive history influences post-reproductive mortality. A potential explanation for this association is confounding by socioeconomic status in the family of origin, as socioeconomic status is related to both fertility behaviours and to long-term health. Kieron Barclay, Katherine Keenan, Emily Grundy, Martin Kolk and Mikko Myrskylä examine the relationship between age at first birth, completed parity, and post-reproductive mortality and address the potential confounding role of family of origin.