The association between chlamydial-specific IgG and IgA antibodies and pregnancy outcome in an in vitro fertilization program.

Chlamydial-specific IgG and IgA antibodies were determined by a single serovar (L2) immunoperoxidase assay (IPA) in the serum of all patients that have conceived in an in vitro fertilization and embryo transfer (IVF & ET) program (n = 106) and in a group of patients that went through the program at the same period of time and did not conceive (n = 94). The prevalence rate of elevated IPA IgG (titers greater than or equal to 1:128) and IPA IgA (titers greater than or equal to 1:16) specific to chlamydiae was significantly higher (P less than 0.001) in the IVF & ET pregnancy loss and nonconception groups ("failures") versus the IVF & ET term pregnancy group ("successes") (74 vs 47%, odds ratio = 4.1, and 34 vs 14%, odds ratio = 4.3, respectively). Stepwise discriminant analysis revealed that elevated specific chlamydial IgG had the greatest effect on the variance between successes and failures in this study group. Our study indicates the possible role of past or chronic active chlamydiae infection on the "take-home baby rate" in an IVF & ET program.