Effects of maternal hyperthyroidism and antithyroid drug therapy on congenital malformation of newborn infants

To evaluate the relationship between the incidence of congenital malformations of newborns and maternal hyperthyroidism with antithyroid drug (ATD) therapy during pregnancy. The clinical data of 100 cases of pregnant women with hyperthyroidism and their 101 offsprings born in Peking Union Medical College Hospital during 1983-2003 were analyzed retrospectively. According to the maternal thyroid function, and antithyroid drugs taken during the first trimester of pregnancy, subjects were divided into different groups. The incidence of congenital malformations of newborns and risk factors, especially the effects of maternal hyperthyroidism with antithyroid drug therapy were analysed. The prevalence of congenital malformation in infants born to mothers who had hyperthyroidism during pregnancy (6.9%, 7/101) was significantly higher than that of all the infants born in the same hospital during the same period (0.9%, 212/22 765, P < 0.01). The difference of the incidence of malformed infants born to mothers with hype