Autoimmunity during pregnancy and urticaria in offspring by age 3 years: A prospective cohort study

Urticaria is a global public health concern that incurs considerable costs and diminishes the patient's quality of life. Despite the potential association of autoimmunity with urticaria and the contribution of genetic predisposition, the impact of maternal autoimmune predisposition on urticaria in offspring remains unclear. Using antinuclear antibody (ANA) as an indicator of autoimmunity, we investigated the association of maternal ANA positivity with offspring urticaria by age 3 years. This prospective cohort study was conducted as an adjunct to the Japan Environment and Children's Study. ANA levels were determined using indirect immunofluorescence analysis with HEp-2 cells, and ANA positivity during pregnancy was defined as an antibody titer of 1:40 or higher at both the first and the second/third trimesters measurements. Clinical data related to childbirth were obtained from physician's records, while other data were collected through self-administered questionnaires completed by the mothers and fathers. The participants with stillbirth, multiple births, miscarriage or autoimmune diseases were excluded, and a total of 776 mother-child pairs included in the analysis. Among the mothers, 98 (12.6%) tested positive for ANA at both pregnancy time points. Among the children, 29 (3.7%) developed urticaria by age 3 years. Logistic regression analysis, adjusted for covariates, showed that maternal ANA positivity at both pregnancy time points was significantly associated with offspring urticaria by age 3 years (adjusted odds ratio, 2.74; 95% confidence interval: 1.16-6.46). This finding suggest that the mother's immune status may play a role in the development of childhood urticaria.