Background: It has recently been suggested that an atopic phenotype may already be programmed in utero. We examine here the association between prenatal factors and the subsequent development of allergic rhinitis and eczema among offspring.
Methods: The analyses were based on 8088 children in a population-based prospective birth cohort started in northern Finland in 1985-6.
Results: The prevalences of allergic rhinitis and allergic eczema by the age of 7 years among 8088 children were 3.3% and 6.7%, respectively. The results indicate that low parity, febrile infections in pregnancy, and the use of contraceptives before pregnancy increased the risk of allergic disorders among children. Bleeding in the first trimester and a greater weight gain during pregnancy appeared to be risk factors for rhinitis only. Children whose mothers experienced infections in the first trimester had ORs of 2.65 (95% CI 1.50-4.69) for rhinitis and 1.63 (95% CI 1.00-2.69) for eczema after adjustment for potential confounders.
Conclusions: Obstetric complications and infection in pregnancy may increase the risk of allergic disorders among the offspring.