[Apparent transitory hyperthyrotropinemia of mothers and newborn infants related to the presence of maternal immunoglobulins].

Abstract

Some newborns infants (screened for congenital hypothyroïdism) and their mothers were found to present an apparent isolated hyperthyrotropinemia. A large molecular size material (150 000 dalton) was found to carry the apparent immunoreactivity and was characterized as immunoglobulins, capable of binding TSH as well as Rabbit IgG. These maternal immunoglobulins are passively transferred to the newborn infants and interfere in various radioimmunoassays.