Introduction & Objective: Spontaneous pregnancy loss is the most common complication of pregnancy. However, after a thorough evaluation the potential cause remains unexplained in about half of the cases. Autoimmune disorders appear to play a prominent role among multiple factors implicated in pathogenesis of adverse pregnancy outcome, including thyroid antibodies .The purpose of this study is determination of antithyroid antibodies titer on the outcome of recent pregnancy that aborted or continued until delivery.

Materials & Methods: This study was descriptive cross sectional research .The information of 80 pregnant women being between 20 to 40 years old with gestational age of below 20 weeks were gathered for this study. 40 of these women aborted within 20 weeks and others, their pregnancies continued until delivery. All samples with known causes of abortion were waived. With written consents , blood of each pregnant woman was taken for the examination of antithyroid antibodies , FBS and TFT. If the two latters results were normal , the antithyroid antibodies were considered to be valid and the information was registered in prepared questionnaires. The values more than 75 u/ml for anti Tpo and 100 u/ml for anti TG were abnormal. Afterwards , using excel program the data were gathered , and the results were analyzed with t-test , c2 and spss software .

Results: 8 out of 80 women , had abnormal antibody results 6 women had abnormal anti TG while 3 women had abnormal anti Tpo , and in one case both of them were abnormal . 7 out of 8 women who had abnormal antibody were in the group aborted and one of them was in the group who delivered her baby. The results show that the differences of anti thyroid antibodies between the 2 groups were statistically meaningful.

Conclusion: The results show that the differences of antithyroid antibodies between the two groups were statistically significant. Furthermore , significant levels of these antibodies were only in the group with recent pregnancy abortion and were not dependent on their previous abortion