Intravenous immunoglobulin (IVIG) and recurrent spontaneous pregnancy loss

Some cases of unexplained recurrent spontaneous pregnancy loss have been proposed to arise from an undefined immunological barrier to normal placentation. One proposed treatment, active immunization with allogeneic leukocytes, benefits only 8% to 10% of treated couples, who cannot be selected by means of diagnostic testing (1). Another treatment, passive immunization with intravenous immunoglobulin (IVIG), was promising in uncontrolled trials (2). IVIG, which is human IgG prepared from pooled plasma, has a diverse antibody profile because thousands of donors contribute to the pool (3).