Rationale: Maternal diet during pregnancy has the potential to affect airway development and to promote T-helper-2-cell responses during fetal life. This might increase the risk of developing childhood asthma or allergy.
Objectives: We investigated the influence of maternal food consumption during pregnancy on childhood asthma outcomes from 1 to 8 years of age.
Methods: A birth cohort study consisting of a baseline of 4,146 pregnant women (1,327 atopic and 2,819 nonatopic). These women were asked about their frequency of consumption of fruit, vegetables, fish, egg, milk, milk products, nuts, and nut products during the last month. Their children were followed until 8 years of age. Longitudinal analyses were conducted to assess associations between maternal diet during pregnancy and childhood asthma outcomes over 8 years.
Measurements and main results: Complete data were obtained for 2,832 children. There were no associations between maternal vegetable, fish, egg, milk or milk products, and nut consumption and longitudinal childhood outcomes. Daily consumption of nut products increased the risk of childhood wheeze (odds ratio [OR] daily versus rare consumption, 1.42; 95% confidence interval [95% CI], 1.06-1.89), dyspnea (OR, 1.58; 95% CI, 1.16-2.15), steroid use (OR, 1.62; 95% CI, 1.06-2.46), and asthma symptoms (OR, 1.47; 95% CI, 1.08-1.99).
Conclusions: Results of this study indicate an increased risk of daily versus rare consumption of nut products during pregnancy on childhood asthma outcomes. These findings need to be replicated by other studies before dietary advice can be given to pregnant women.