PROBLEM: Certain Th-2 cytokines and granulocyte-macrophage colony-stimulating factor (GM-CSF) are propitious for the success of pregnancy and recurrent spontaneous abortion (RSA) is often characterized by a failure of Th-2 type responses. These considerations as well as the use of intravenous immunoglobulin (IVIg) in RSA induced us to evaluate the levels of GM-CSF in normal pregnancies, in pregnant women affected with unexplained RSA and the effects of IVIg treatment. METHOD OF STUDY: Peripheral blood free GM-CSF was measured by means of a sandwich enzyme immunoassay in 39 healthy women (13 non-pregnant, 26 pregnant) and in 53 RSA patients (11 non-pregnant, 42 pregnant). In 14 pregnant RSA patients GM-CSF was studied also after the very first IVIg infusion (0.5 g/kg body weight). RESULTS: In healthy women we found a significant increase of GM-CSF during pregnancy, in pregnant RSA patients such an increase was not detected. After IVIg, GM-CSF concentrations were almost doubled. CONCLUSIONS: GM-CSF is found increased in normal pregnancy and is very low during pregnancy in RSA. IVIg infusions are capable of increasing GM-CSF in pregnant recurrent aborters.