Antiphospholipid antibodies associated with implantation failure after IVF/ET

Purpose: Our purpose was to determine the specific antiphospholipid antibodies (APAs) that should be evaluated to identify individuals at risk for implantation failure associated with reproductive autoimmune failure syndrome (RAFS). Methods: The prevalence of APAs among 312 women with implantation failure was compared with that of 100 fertile control women. To be included in the implantation failure group, each woman had to have had at least 12 embryos transferred without subsequent positive pregnancy rest. Enzyme-linked immunoabsorbant assay was used to measure IgG, IgM, and IgA anticardiolipin, antiphosphatidyl ethanolamine, antiphosphatidyl inositol, antiphospatidic acid, antiphosphatidyl glycerol, antiphosphatidyl choline, and antiphosphatidyl serine. Results: When the values for each of the seven APAs in three isotypes were compared between women with implantation failure and the control population, all of the APAs tested had a significantly higher frequency among women with implantation failure. Positive APAs were detected in 69 (22%) of the 312 women with implantation failure compared with 5 (5%) of the 100 control women (P < 0.0001). Anticardiolipin antibodies were found in 13 (4%) of the 312 women with implantation failure and none of the controls. Fifty-six (18%) of the 312 with implantation failure were negative for anticardiolipin antibodies but had positive values of other APAs. Conclusions: A complete APA panel using seven isotypes is necessary for diagnosing implantation failure associated with RAFS. If only anticardiolipin antibody is measured 4% (13/312) of the positive APAs are detected, and 81% (56/69) of women with implantation failure associated with RAFS will have the diagnosis missed.