Sex‐Specific Differences in Perinatal Risk Factors for Atopic Dermatitis: A Large Retrospective Population‐Based Cohort Study

AIM: This study was designed to determine whether gestational age at birth, the method of delivery, or birth weight were associated with the risk of developing atopic dermatitis (AD), and whether the association of risk factors differed between the sexes. METHODS: A large population-based Northern Finland Birth Cohort 1986 Study that has been followed since birth. The dataset consisted of 8993 subjects who were divided into two groups based on presence or absence of AD. RESULTS: The prevalence of AD was 23.7%. The probability of later AD was unaffected by either method of delivery or gestational age at birth. However, low birth weight compared to normal birth weight was a protective factor against AD, albeit only in men (adjusted risk ratio RR 0.54 [95% CI 0.30-0.97]). No such effect was observed in women. CONCLUSIONS: These findings suggest the existence of sex-specific risk factors for AD.