Shaheen SO, et al. - This study explored the link between maternal haemoglobin concentrations in pregnancy and childhood respiratory and allergic outcomes. Findings suggested no association of maternal haemoglobin with risk of childhood asthma or other allergic disorders but lower maternal haemoglobin during gestation was identified as a possible risk factor for allergic sensitisation, elevated IgE and lower FVC in childhood, which may reflect effects of lower prenatal iron status.