Intrauterine exposure to maternal enterovirus infection as a risk factor for development of autoimmune thyroiditis during childhood and adolescence.

Maternal intrauterine enterovirus infection during pregnancy increases the risk for the offspring to develop type 1 diabetes mellitus. Type 1 diabetes mellitus and autoimmune thyroiditits (AIT) are closely linked. A common pathogenetic factor is possible. The objective of this study was to investigate a possible association between maternal enterovirus infection during pregnancy and the development of AIT in the offspring. Sera taken at delivery from 31 mothers whose children subsequently developed AIT was analyzed for immunoglobulin (Ig)A, IgG, and IgM antibodies against enterovirus, and compared to a control group comprising 233 randomly selected maternal sera. Of the mothers whose children developed AIT, 5 of 31 (16%) were enterovirus IgM-positive, compared to 17 of 233 (7%) in the control group (p = 0.16). The age at diagnosis of AIT was significantly lower in the group of children with IgM-positive mothers compared to children with IgM-negative mothers (p < 0.05). In addition, 3 children (60%) in the IgM-positive group were overtly hypothyroid at diagnosis of AIT, compared to no child (0%) in the IgM-negative group (p < 0.01). No significant differences were found in IgA and IgG antibody titers between the mothers whose children developed AIT and the control group. Although this study did not have enough power to reveal intrauterine exposure to maternal enterovirus infection during pregnancy as a risk factor for development of AIT during childhood and adolescence, it suggested an association with earlier onset of clinical disease in children to enterovirus IgM-seropositive mothers.