The occurrence of circulating Wuchereria bancrofti microfilariae was investigated in 304 pregnant women from the "Unidade Mista Pof. Barros Lima" and "Hospital das Clínicas/UFPE". The filtration technique was employed to detect microfilaraemia during pregnancy, and 13 women were found to be positive (4.2%). The investigation of microfilariae in the cord blood of their children was negative (6/13), and also in venous blood samples collected up to 72 hours after birth and with 6 months of life. Milk samples from these mothers also had no microfilariae. The authors suggest that the occurrence of placentary lesions may be a possible factor involved in the transplacental transfer of microfilariae, and that in utero exposure to microfilariae and/or filarial antigens may influence the response to a filarial infection acquired later, thus being important a clinical and laboratorial follow-up of children exposed previously to filarial antigens during early periods of human development.