ObjectiveThe objective of this study was to investigate the associations between maternal exposure to anxiety during pregnancy and the susceptibility of offspring to eczema and allergic rhinitis and the possibility of sensitivity periods and cumulative effects. MethodsThe study's sample consisted of 3160 mother-child pairs from the Ma'anshan Birth Cohort Study. Maternal anxiety was repeatedly measured in the 1st, 2nd, and 3rd trimesters of pregnancy using the Chinese version of the Pregnancy-Related Anxiety Scale. Information regarding children's eczema and allergic rhinitis diagnoses was collected through parental reports at 12, 24, 36 and 48 months of age. Binary logistic regression models were used for statistical analysis and corrected for multiple comparisons using the false discovery rate (FDR) method. ResultsChildren whose mothers experienced anxiety throughout pregnancy had the highest odds of developing total eczema (aOR 1.45, 95% CI 1.02–2.07) and total allergic rhinitis (aOR 1.67, 95% CI 1.17–2.37) between the ages of 6 and 48 months. The higher the trajectory of the maternal anxiety scores throughout pregnancy, the higher the odds of total eczema (aOR 1.65, 95% CI 1.14–2.40) and allergic rhinitis (aOR 1.84, 95% CI 1.28–2.66) in their offspring. The association between maternal anxiety and children's eczema was mainly concentrated in the first 24 months, whereas the association with allergic rhinitis was mainly concentrated in the 36–48 months. ConclusionMaternal anxiety during any trimester of pregnancy, especially with a consistently high trajectory of anxiety scores, was associated with higher odds of children's eczema and allergic rhinitis.