Background: Association of early pregnancy body mass index (BMI) and maternal gestational weight gain (GWG), and asthma and allergic disease in children is unclear. Methods: We analyzed data from 3,176 mother-child pairs in a prospective birth cohort study. Maternal anthropometric measurements in the first and last antenatal clinic visits were obtained through post-delivery questionnaires to calculate early pregnancy BMI and maternal GWG. Asthma and allergic diseases in children by the age of 5 years was assessed using a validated questionnaire. Furthermore, serum samples were analyzed for IgE antibodies to eight allergens. We applied Cox proportional hazards and logistic regression analyses to estimate the association of early pregnancy BMI and maternal GWG (as continuous variables and categorized into quarters), and asthma, atopic eczema, atopic sensitization, and allergic rhinitis in children. Results: Early pregnancy BMI and maternal GWG were not associated with asthma and allergic disease in children when analyzed as continuous variables. Compared to the first quarter (GWG <0.32 kg/week), mothers in the third quarter (GWG 0.42-0.52 kg/week) had children with higher odds of developing atopic eczema (adjusted OR 1.49, 95% CI [1.13-1.96]) by age 5 years. Conclusion: The association of early pregnancy BMI and maternal GWG and asthma and allergic disease in children is inconsistent. High maternal GWG may be associated with increased odds of atopic eczema.

Background: Enterovirus (EV) infections, being among the most prevalent viruses worldwide, have been associated with reduced risk of allergic diseases. We sought to determine the association of EVs with allergic sensitization and disease in early childhood. Methods: The study was carried out in a nested case-control setting within a prospective birth cohort in Finland. We included 138 case children who had specific IgE (s-IgE) sensitization at the age of 5 years and 138 control children without s-IgE sensitization. Allergic disease was recorded at study visits and asked with ISAAC questionary. We screened for the presence of serotype specific antibodies against 41 EVs at 1 to 5 years of age and assessed their association with allergic sensitization and disease. Results: The overall number of EV infections did not differ between s-IgE-sensitized children and non-sensitized control children. However, there was a tendency of case children with an allergic disease having less EV infections than their controls. This observation was statistically significant for species A EVs in case children with atopic dermatitis vs. control children: OR 0.6 (95 % CI 0.36-0.99), P = 0.048. Conclusion: This study supports the evidence that EV exposure and development of allergic disease are inversely associated. Interestingly, the inverse association was not observed for bare atopic IgE sensitization, but for IgE sensitization coupled with clinical atopic disease. This suggests that environmental factors influencing IgE sensitization may differ from those influencing progression to clinical allergic disease.