Objective Previous evidence suggests that women with a history of adverse pregnancy outcomes (APOs) may be at greater risk of developing rheumatoid arthritis. Additionally, one study reported that female patients with rheumatoid arthritis with a history of preonset APOs showed a worse 2-year radiographic outcome than did patients with no APOs. The authors' aim was to investigate the relationship between preonset APOs (spontaneous abortion or stillbirth) and disease outcome in women with inflammatory polyarthritis (IP). Methods The Norfolk Arthritis Register (NOAR) is a primary-care-based cohort of patients with recent-onset IP; 1586 gravid women who joined NOAR during 1990–2004 were included in this analysis. The authors examined the relationship between patient-reported preonset APOs and disease outcome, measured using the Health Assessment Questionnaire (HAQ) and disease activity score in 28 joints (DAS28CRP) (for a subgroup of patients), using linear random effects analysis, adjusted for age and other factors. Results In a predominantly parous cohort (99%), 397 (25%) women reported =1 APO before symptom onset. The rates of APOs in NOAR were comparable to the general population. On average, women with a history of =2 APOs had significantly higher HAQ and DAS28 scores over time than women with no APOs (mean difference in HAQ 0.13 (95% CI 0.002 to 0.26); DAS28, 0.56 (95% CI 0.01 to 1.11)). This relationship was more pronounced in women with =3 APOs (mean difference in HAQ 0.23 (95% CI 0.02 to 0.43); DAS28, 0.98 (95% CI 0.23 to 1.74)). Conclusion Women with two or more APOs before IP onset had a worse disease outcome than women with no APOs.