Yoshida K, Wang J, Malspeis S, et al. - Childhood parental smoking was shown to exert a potential direct impact on adult-onset incident seropositive rheumatoid arthritis (RA) even after controlling for adulthood personal smoking (hazard ratio HR: 1.75).

• Analysis of the Nurses’ Health Study II prospective cohort, including 90,923 women of whom 532 incident RA cases (66% seropositive) were detected during a median of 27.7 years of follow-up.

• An association was found between maternal smoking during pregnancy and RA, post-adjustment for confounders [HR 1.25] but not after accounting for subsequent smoking exposures.

• Childhood parental smoking was identified to be related to seropositive RA, post-adjustment for confounders (HR 1.41).

• Adulthood passive smoking was not significantly related to RA (HR 1.30 for ≥20 years of living with a smoker vs none).