Current international dietary guidelines advise people to reduce their consumption of sugar. Whilst clues are emerging that a high consumption of sugar in childhood may increase the risk of asthma, the relation between maternal sugar intake during pregnancy and respiratory and atopic outcomes in the offspring has been little studied.In the population-based birth cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC), we analysed associations between maternal intake of total sugar, free sugars and added sugar in pregnancy (estimated by food frequency questionnaire in the last trimester) and current doctor-diagnosed asthma (n=7677), current wheezing (n=7762), atopy (n=6117), serum total IgE (n=4843), forced expiratory volume in 1 second (FEV1; n=5308) and forced vital capacity (FVC; n=5387) at 7-9 years of age.After controlling for potential confounders, maternal intake of total sugar was positively associated with wheeze (odds ratio for top vs bottom quintile of sugar intake [95% CI]: 1.36 [0.98-1.90]), atopy (OR: 1.38 [1.04-1.83]) and total IgE (geometric mean ratio for top vs bottom quintile of sugar intake [95% CI]: 1.23 [1.00-1.53]). Positive associations were also found between maternal intake of free sugars and asthma, wheeze and atopy (ORs: 1.31 [0.98-1.75], 1.42 [1.05-1.92] and 1.38 [1.06-1.78], respectively). In post hoc analyses maternal intake of total and free sugars was strongly positively associated with atopic, but not non-atopic, asthma. Maternal intake of added sugars was negatively associated with FEV₁ and FVC (p for trend: 0.04 and 0.004, respectively).Maternal intake of sugar during pregnancy is associated with respiratory and atopic outcomes in childhood.