Os autores submeteram 500 recém-nascidos a teste simplificado (Rapi Tex IgM) que por simples reação de aglutinação evidencia quantidades anormalmente elevadas de IgM no sangue do cordão umbilical. Os resultados obtidos pela triagem foram avaliados através de dosagens de IgM no sangue do cordão umbiblical, exame morfológico de placentas (macro e microscopia); acompanhamento clínico e laboratorial de alguns casos e exame anatomopatológico dos casos em que ocorreu o óbito. Concluem pela validade do teste na triagem de Infecções pré-natais.The authors submitted 500 newborns to a simplified test (Rapi Tex Igm) which, by the simple agglutination reaction, presented abnormally increased quantities of IgM in the blood of the umbilical cord. The results obtained by this selection were evaluate through IgM dosages of the blood in the umbilical cord, morphological examination of placentas (macro and microcopy) medical and laboratory follow-up of some cases and anatomopathologic examination of cases in which death occured. They have reached the conclusion that the test invalid for the selection of pre-natal infections.