Background: The most frequent adverse pregnancy result is miscarriage. Pregnancy-related major changes and their effects on the mother and fetus are linked to thyroid antibodies and thyroid diseases.Objectives: The aim of the presented study is to compare the miscarriages caused by thyroid diseases and autoimmune diseases in the first trimester of pregnancy., by the following objectives: 1-measurement FT3, FT4 and TSH 2-Antibody determination of TPO and anti-tg 3antiphospholipid antibodies Methodology: The study was conducted during the period from 1st of February 2022 to the 1st of April 2022, the number of participant become 120(100 patient and 30 control ) female .Their age were ranged from 19 -46 years, sample were attended from Hospital women and children in the province of AL-Anbar. pregnant women with miscarriage were divided into thyroid disorders(51) and autoimmune diseases(49) to compare between thyroid hormones and antithyroid hormones between the two groups and to know the percentage of thyroid disorders in relation to autoimmune diseases. The Statistical Analysis System-SAS (2012) program was used to detect the effect of different factors in study parameters.Results: The prevalence of thyroid disorder and autoimmun disease during pregnancy was 100 out of which 49 had thyrorid disorde and 51 had autoimmun disease. there is a significant difference ( P≤ 0.001) of abortion in miscarriage pregnant women with thyroid disorder compere to in autoimmune disease. The mean and standard deviation of anti-tpo are higher in Rm with Autoimmune thyroid disease compared to other groups. anti-tg and APL are higher in pregnancy with Autoimmune thyroid disease compared to Thyroid disorder. no significant difference between TSH and FT3 in patient with autoimmune and thyroid disorder despite the mean ± sd in TD is lower than AID and high significant (p≤0.05)in level of FT4.CONCLUSION: Women with a positive autoimmune disease may be more likely to have a pregnancy loss than if they have a thyroid disorder.