Post implantation pregnancy losses are psychologically and economically str
essful to the childbearing population. The etiology in the vast majority of
cases is unknown but is partly thought to result from a breakdown of the m
aternal tolerance to the fetoplacental unit. Immunologically based therapy
remains controversial but no alternative therapy is available at the moment
. This article reviews the conceived immunological basis of recurrent pregn
ancy losses, discussing the controversies arising, and recommending the use
of intravenous immunoglobulin, IVIg, in well controlled experiments for fu
rther clinical trials.