Risk factors of primary thyroid dysfunction in early infants born to mothers with autoimmune thyroid disease.

AIM: To assess whether the state of maternal thyroid function and the pattern of thyroid alterations during gestation would affect the infants' thyroid function and to evaluate the risk factors affecting early infants' thyroid function by means of multiple logistic regression. METHODS: In a cross-sectional study, 78 neonates born to mothers with Graves disease or Hashimoto thyroiditis were examined and followed clinically and biochemically. Neonates born to healthy mothers during the same period were set as controls. Tests of thyroid function, antithyroid peroxidase antibody (TPOAb), antithyroglobulin antibody (TGAb), anti-TSH receptor antibody (TRAb) and antithyroid-stimulating antibody (TSAb) were performed both in early infants and their mothers. All possible maternal and/or infantile risk factors for thyroid dysfunction during early infancy were analysed by means of multiple-factor logistical regression. RESULTS: The overall prevalence of underlying subtle thyroid abnormalities in these 78 infants was 52.6%, which was significantly higher than that witnessed among infants from healthy mothers (5.4 per thousand, p<0.01). By using multiple logistic regression analysis, the state of maternal thyroid function in gestation, the type of autoimmune thyroid disease during pregnancy and the level of TRAb in the newborn were significantly correlated with the early infants' thyroid dysfunction. CONCLUSION: Maternal autoimmune thyroid disease during pregnancy will affect infant thyroid function. Therefore, appropriate management of maternal autoimmune thyroid disease throughout pregnancy is essential in the prevention of undesirable neonatal outcomes.