Maternal asthma and lung function during pregnancy, childhood asthma and growth, the MAESTRO-Child study

<bold>Aim:</bold> Maternal asthma is associated with childhood asthma and low birthweight. We studied if maternal asthma/allergic asthma and maternal lung function is associated with childhood asthma and growth. <bold>Method:</bold> Data from a Swedish pregnancy cohort [Maternal Asthma Events Stress and Offspring (MAESTRO)] was linked to data from the children [MAESTRO-Child] and to national health registers [529 mother/child pairs]. Pre- and post-bronchodilator FEV1, FVC and FEV1/FVC z-score was measured in pregnancy. Maternal asthma, childhood asthma at 6 years and growth z-scores at 6, 12, 18 and 36 months were defined from self- or parent-reported questionnaires and/or register data. Maternal allergic asthma was defined as asthma and allergic sensitisation (positive PhadiatopTM). Associations between maternal asthma/allergic asthma/lung function and childhood asthma/growth was studied using multivariable regression models. <bold>Results:</bold> Maternal asthma and allergic asthma were associated with an increased risk of childhood asthma [adj risk ratio(RR) 1.99 (95% CI 1.28, 3.10) and 2.24 (1.37, 3.66) respectively]. Higher maternal post-bronchodilator FEV1 was associated with a reduced risk of childhood asthma [adj RR 0.58 (0.36, 0.92)]. There were no statistically significant associations for FVC or FEV1/FVC and childhood asthma or the relationship between maternal asthma/allergic asthma/lung function and childhood growth. <bold>Conclusion:</bold> Maternal asthma/allergic asthma is a risk factor for childhood asthma and higher FEV1 in pregnancy may be associated with reduced risk for childhood asthma. Maternal asthma/allergic asthma/lung function does not appear to have a significant association with childhood growth.