Double Trouble: The Burden of Child-rearing and Working on Maternal Mortality.

We document increased old-age mortality rates among Swedish mothers of twins compared with mothers of singletons, using administrative data on mortality for 1990-2010. We argue that twins are an unplanned shock to fertility in the cohorts of older women considered. Deaths due to lung cancer, chronic obstructive pulmonary disease, and heart attacks-all of which are associated with stress during the life course-are significantly increased.