In Vitro Fertilization (IVF) has been employed for more than four decades. A crucial concern is the etiology of infertility due to the fact that it may range widely, from reproductive system anatomy and endometrium receptivity to multisystem disorders and several immunologic factors. Among the immune pathologies that could compromise fertility are the autoantibodies affecting thyroid function. Infertile women are in a great prevalence of thyroid autoimmune disorders. However, there are still unsatisfactory data regarding the direct impact of thyroid autoantibodies (TAA) on IVF outcome. The aim of this study is to provide a comprehensive review of the impact of thyroid autoantibodies on the possibilities of a successful IVF cycle outcome.
PubMed/Medline, Embase and Cochrane Central databases were thoroughly searched. Only fourteen studies were assessed as eligible for the present comprehensive review, and their design and outcome measures -namely clinical pregnancy, live birth rate, and miscarriage rate- are presented herein.
The great majority of the published studies demonstrated that TAA presence in euthyroid women does not appear to be associated with statistically significant different outcomes following IVF treatment. A trend towards a higher miscarriage rate in TAA positive women was reported in several studies. However, this observation was not confirmed by other studies. In addition, studies presented with a high heterogeneity hence robust conclusions could not be safely sourced.
In conclusion, well-designed prospective cohort studies are imperative in order to define the direct impact of TAA on IVF cycle success. The contribution of future studies is of significance especially in light of the fact that autoantibodies and their role in infertility treatment is still be undervalued, and underrepresented, as evident by the lack of data published on this complex field.