Purpose: To evaluate the efficacy of passive immunotherapy in preventing miscarriage. Methods: Studies both pro and con concerning intravenous immunoglobulin therapy (IVIG) in preventing miscarriage were evaluated. A new therapy of IV intralipid infusion is also reviewed. Results: Intravenous immunoglobulin therapy may be effective but it is necessary to use it prior to conception and monthly thereafter. Some brands are more potent than others. The data concerning intralipid IV infusion involves only small case series but the results from one study were encouraging though we could not personally substantiate these findings. Conclusions: Intravenous immunoglobulin therapy is very expensive. In the author’s opinion there are no immunological studies that can determine if a woman needs immune suppression. The best way to decide is the history – the more miscarriages without any other identifiable cause the more likely passive immunotherapy may be helpful. If intralipid proves as efficacious as IVIG it will be a lot less expensive.