Endocrine Abstracts

JOINT3641

Introduction: Data on whether thyroid autoimmunity negatively affects assisted reproduction outcomes in euthyroid women are conflicting: Some meta-analyses suggest antithyroid autoantibodies (ATA) negatively impact ART outcomes, while others find no effect. A closer look shows that TSH levels and the degree of ATA elevation are key factors to consider. Another crucial element is the better ART outcomes in ATA(+) women with ICSI compared to IVF. The rise of ICSI and evolving definitions of SCH may explain the trend of reduced impact of ATA in recent studies, as well as the contradictions with older studies. These opposing data have prompted us to formulate the following research question: In euthyroid women of infertile couples undergoing ART, does the presence of ATA lead to fewer pregnancies, more miscarriages, and ultimately fewer live births?.

Material and Methods: Following PRISMA guidelines, we searched PubMed, Embase, and Cochrane databases from January 2006 to April 2024 for observational studies comparing the impact of ATA on clinical outcomes in euthyroid ATA(+) vs. ATA(-) women undergoing ART, using strict inclusion and exclusion criteria. Possible confounding parameters were extracted from each study, and quality was assessed with the NOS scale. Due to variability among studies, a qualitative synthesis was employed. Desired outcomes were clearly defined, and the calculation method (based on participants, pregnancies, or total ART cycles) was carefully evaluated.

Main Results: 35 studies were eligible for inclusion. Of 14 studies on the biochemical pregnancy rate, 3 found significant differences. For clinical pregnancy rate, 4 of 29 studies showed lower CPR in ATA(+) women. 1 of 6 studies on ongoing pregnancy rate found a decrease in ATA(+) women. In delivery rate, 1 of 4 studies reported a lower rate. 7 of 28 studies on miscarriage rate indicated higher MR in ATA(+) women. The live birth rate was lower in 2 of 15 studies. None of the 3 studies on cumulative live birth rate showed adverse effects. To improve comparability, studies with similar features were grouped. Emphasis was placed on studies examining cumulative live birth rate, first IVF attempt, and large sample size.

Conclusion: Most studies found no negative impact of ATA on IVF outcomes. Although some data suggest otherwise, particularly for MR, studies with larger sample sizes or those focusing on the first IVF attempt show no adverse effect of ATA. Similarly, ATA positivity does not appear to affect CLBR.