Background Single motherhood is associated with poorer health, but whether this association varies between countries is not known. We examine associations between single motherhood and poor later-life health in the USA, England and 13 European countries.

Methods Data came from 25 125 women aged 50+ who participated in the US Health and Retirement Study, the English Longitudinal Study of Ageing and Survey of Health, Ageing and Retirement in Europe. We tested whether single motherhood at ages 16–49 was associated with increased risk of limitations with activities of daily living (ADL), instrumental ADL and fair/poor self-rated health in later life.

Results 33% of American mothers had experienced single motherhood before age 50, versus 22% in England, 38% in Scandinavia, 22% in Western Europe and 10% in Southern Europe. Single mothers had higher risk of poorer health and disability in later life than married mothers, but associations varied between countries. For example, risk ratios for ADL limitations were 1.51 (95% CI 1.29 to 1.98) in England, 1.50 (1.10 to 2.05) in Scandinavia and 1.27 (1.17 to 1.40) in the USA, versus 1.09 (0.80 to 1.47) in Western Europe, 1.13 (0.80 to 1.60) in Southern Europe and 0.93 (0.66 to 1.31) in Eastern Europe. Women who were single mothers before age 20, for 8+ years, or resulting from divorce or non-marital childbearing, were at particular risk.

Conclusions Single motherhood during early-adulthood or mid-adulthood is associated with poorer health in later life. Risks were greatest in England, the USA and Scandinavia. Selection and causation mechanisms might both explain between-country variation.