Dietary patterns in pregnancy and respiratory and atopic outcomes in childhood

Background: Studies of the relation between maternal diet in pregnancy and respiratory and atopic outcomes in the offspring have focused on the effects of individual nutrients and foods rather than dietary patterns. A study was undertaken to determine whether dietary patterns in pregnancy are related to childhood asthma and related outcomes. Methods: In a population-based birth cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC), dietary patterns in pregnancy previously identified using principal components analysis ("health conscious", "traditional", "processed", "vegetarian" and "confectionery") were related to early wheezing phenotypes and eczema; wheezing, hay fever, eczema, doctor-diagnosed asthma, atopy and total IgE at 7 years; lung function and bronchial responsiveness at 8-9 years. In regression models, confounders were controlled for using propensity scores. Results: Univariately, the "health conscious" pattern was positively associated with eczema, total IgE, forced expiratory volume in 1 s and forced expiratory flow and negatively associated with early wheezing and asthma (unadjusted odds ratios per standard deviation increase in pattern score for early persistent wheeze and asthma: 0.78 (95% CI 0.70 to 0.87), p=7.3 x 10(-6), N=8886 and 0.90 (95% CI 0.84 to 0.97), p=0.007, N=7625, respectively). The "processed" pattern was positively associated with early wheezing and negatively associated with atopy and forced vital capacity. On controlling for confounders, the effects were substantially attenuated and became non-significant (adjusted odds ratios for the associations of the "health conscious" pattern with early persistent wheeze and asthma: 1.00 (0.86 to 1.16), p=0.99 and 0.95 (0.86 to 1.04), p=0.27, respectively). Conclusions: In this cohort, dietary patterns in pregnancy did not predict asthma and related outcomes in the offspring after controlling for confounders.