RESUMO
OBJECTIVE: To evaluate the influence of perinatal environmental factors on early sensitization, atopic dermatitis and wheezing during the first year. METHODS: Information on pregnancy-related factors, parental atopic history, environmental factors and the clinical course of the infant until age one was gathered by questionnaires, as part of a prospective birth cohort study (Prospective study on the Influence of Perinatal factors on the Occurrence of asthma and allergies [PIPO-study]). Quantification of total and specific IgE was performed in 810 children and their parents. RESULTS: Early sensitization was found in 107/810 (13%) of the infants. Multiple regression analysis showed that specific IgE in fathers was a risk factor for early sensitization in their daughters (adjusted odds ratios (OR(adj)) 2.21 (95% confidence interval (CI) 1.10-4.49); P=0.03), whereas in boys, day care attendance was shown to be protective for early sensitization (OR(adj) 0.38 (95% CI 0.20-0.71); P=0.001). Atopic dermatitis occurred in 195/792 infants (25%). Specific IgE in the mother (OR(adj) 1.52 (95% CI 1.06-2.19); P=0.02) and in the infant (OR(adj) 4.20 (95% CI 2.63-6.68); P<0.001) were both risk factors for the occurence of atopic dermatitis, whereas postnatal exposure to cats was negatively associated with atopic dermatitis (OR(adj) 0.68 (0.47-0.97); P=0.03). Postnatal exposure to cigarette smoke (OR(adj) 3.31 (95% CI 1.79-6.09); P<0.001) and day care attendance (OR(adj) 1.96 (95% CI 1.18-3.23); P=0.009) were significantly associated with early wheezing, which occurred in 25% (197/795) of the infants. CONCLUSION: The effect of paternal sensitization and day care attendance on sensitization is gender dependent. Maternal sensitization predisposes for atopic dermatitis, whereas postnatal exposure to cats had a protective effect.