A specific effect of intravenous immune globulin (IVIG) on the outcome of pregnancy in patients with a history of habitual abortion has been postulated as an alternative to immunotherapy with allogeneic leucocytes. The results of different pilot studies have been promising, demonstrating a successful outcome of pregnancy in approximately 80% of treated patients. However, the evaluation and interpretation of the study results has to take into account that the probability of a successful pregnancy in women with a history of three spontaneous abortions is about 60% without treatment. Specific pharmacological effects therefore have to be verified in controlled studies in order to rule out psychological (placebo) effects. A specific therapeutic effect could not be verified in a German randomized, double-blind, multicentre trial in comparison to human albumin 5% which was used as a placebo. The result of another controlled study currently underway in the USA is expected.