Received April 02, 2017
Accepted August 07, 2017

Women submitted to ART treatment correspond to a selected subgroup. Several studies have described the relation between TAI and the outcomes of pregnancies as a result of ART, with contradictory results. The purpose of this systematic review is to determine the association between TAI and the risk of abortion in pregnancies resulting from ART. MEDLINE via PubMed, LILACS and Embase were searched for studies, published in peer-reviewed journals from 1999 to 2017. Studies were summarized using the fixed effects model and the Peto´s method to obtain RR in order to obtain the association between TAI and spontaneous abortion. Only four articles were considered for the systematic review and meta-analysis. From the 210 clinical pregnancies with antithyroid antibodies, 31 had a miscarriage; whereas out of the 1.371 pregnancies without antithyroid antibodies, 158 experienced an abortion. Once the meta-analysis was performed, there was no association between TAI and a higher risk of reproductive loss, RR= 0,94 confidence interval 95%: 0,71-1,24; p=0.879. In conclusion, the presence of antithyroid antibodies is not associated with an increase in the reproductive loss frequency of patients submitted to ART treatment. It is our opinion that the presence of antithyroid antibodies should be considered as a secondary biomarker of autoimmune disease, rather than a real cause of miscarriage in patients submitted to ART. Due to the small amount of evidence regarding this matter, the determination of TAI before initiating ART should be related to the context of the research.