In recent years, with the popularity of thyroid autoantibody testing, it has been found that some women of childbearing age with thyroid disorders or without significant thyroid abnormalities have significantly increased antibodies, especially TPOAb. The following is a brief explanation of the American Guidelines for the Treatment of Thyroid Disorders (ATA Guidelines) to determine whether these antibodies affect pregnancy. We hope this will help. Question 1: What are the possible impairments in thyroid function in pregnant women with positive simple thyroid autoantibodies? In a prospective study conducted by Glinoer et al, 87 women with normal thyroid function and positive TPOAb were evaluated before and during early pregnancy and nearly 20% were found to have TSH >4 mIU/L at the time of pregnancy. Only 19% of women had normal TSH levels at the time of delivery. These studies confirm that in the presence of increased thyroid hormone requirements during pregnancy, an already autoimmune damaged thyroid can develop subclinical hypothyroidism or clinical hypothyroidism. Overall, in antibody-positive patients, residual thyroid function can still meet the needs of pregnancy during the first trimester, but in late pregnancy, a sick thyroid can develop subclinical hypothyroidism or clinical hypothyroidism due to loss of compensation. Question 2; How to treat and monitor a positive thyroid autoantibody (normal thyroid function)? Pregnant women with normal thyroid function but positive thyroid antibodies should be monitored and checked every 4-6 weeks. If TSH is found to be elevated above the normal range, treatment should be given promptly. Since the demand for thyroid hormone gradually increases during pregnancy, continuous monitoring is required in the middle of pregnancy. It should be tested at least once between 26 and 32 weeks of gestation. Recommendation 1: The diagnostic criteria for a positive thyroid autoantibody is a titer of TPOAb above the upper limit of the reference value provided by the kit. A positive thyroid autoantibody alone without an increase in serum TSH and a decrease in FT4 is also referred to as a positive thyroid autoantibody with normal thyroid function. (Recommendation level A) Recommendation 2: Women with normal thyroid autoantibodies need to be monitored regularly for serum TSH during pregnancy. serum TSH should be tested every 4 to 6 weeks during the first half of pregnancy and at least once during 26 to 32 weeks of pregnancy. If TSH is found to be above the pregnancy-specific reference range, L-T4 therapy should be given. (Recommendation level B) Question 3: Is there a link between positive thyroid autoantibodies and miscarriage? Spontaneous miscarriage is the outcome of spontaneous termination of pregnancy at less than 28 weeks of gestation and a fetus weighing less than 1000 g. The Stagnaro-Green study group first noted an association between miscarriage and thyroid autoantibodies. The Glinoer study group reported a 4-fold increase in the risk of miscarriage in TPO-Ab positive patients (13.3% vs. 3.3%, p<0.001) < font="">. In a prospective study, the Sezer study group found no increase in miscarriage in thyroid autoantibody-positive There was no increase in the rate of miscarriage in women (28.6% vs. 20%, p=NS). However, they found that pregnant women with higher titers of TgAb were more likely to miscarry compared to women with full-term pregnancies. A meta-analysis of 8 case-control studies and 10 follow-up studies obtained an association between thyroid autoantibodies and spontaneous abortion (OR 2.30, 95% CI 1.8-2.95). A systematic review and meta-analysis of 31 studies on the association between thyroid autoantibodies and miscarriage was conducted at Queen Mary University of London, UK, of which 19 were cohort studies and 12 were case-control studies involving 12,126 subjects. 28 studies confirmed that thyroid antibodies were significantly associated with miscarriage. The antibody-positive group had a 3-fold higher incidence of miscarriage with an OR of 3.90; the incidence of miscarriage was reduced by 52% in the L-T4 supplementation group. Question 4: Is there a link between thyroid autoantibodies and habitual abortion? Habitual miscarriage is defined as three or more consecutive spontaneous abortions. a case-control study by the Irivani study group found a significantly higher rate of positive thyroid autoantibodies in patients with habitual miscarriage (OR 2.24, 95% CI 1.5 to 3.3). kutteh found that compared to 200 healthy controls, 700 women with positive thyroid autoantibodies had a The Pratt study group reported an increased risk of miscarriage in the next pregnancy in thyroid autoantibody-positive women with habitual miscarriage; however, the Esplin study group found no difference in the rate of thyroid autoantibody positivity between women with habitual miscarriage and healthy controls. Question 5: What is the impact of thyroid autoantibody positivity on assisted reproduction? Some studies reported a significantly increased risk of miscarriage in thyroid autoantibody-positive women undergoing assisted reproduction; other studies did not yield a correlation. A meta-analysis of four studies showed that the risk of miscarriage was increased with positive thyroid autoantibodies (RR l.99, CI 1.42-2.79). Question 6: What is the association between positive thyroid autoantibodies and preterm birth? In the prospective study by Glinoer, a significantly higher rate of preterm birth was found in women with positive thyroid autoantibodies (16% vs. 8%, P<0.005); Ghafoor et al. evaluated 1500 women with normal thyroid function and found a significantly higher incidence of preterm birth in TPO-positive women compared to TPOAb-negative women (26.8 % vs. 8%, P<0.01); Iijima did not find an increased risk of preterm delivery in thyroid autoantibody positive women (3% Vs. 3.1%); Haddow reported a significant increase in premature rupture of membranes in thyroid antibody positive women during the first trimester without an increased incidence of preterm delivery. The latter data showed an association between very preterm birth (preterm birth occurring before 32 weeks of gestation) and positive thyroid autoantibodies [OR 1.73 (1.00 to 2.97)). Five studies analyzing the association between thyroid autoantibodies and preterm birth in 12,566 subjects at Queen Mary University of London, UK, suggested that the incidence of preterm birth was 2-fold higher in the antibody-positive group (OR 2.07) and that L-T4 treatment reduced the risk of preterm birth by 69%. There is only one prospective intervention trial from Negro et al. that showed an increased risk of preterm delivery in women with normal TPOAb compared to women with negative TPOAb (22.4% vs. 8.2%, P<0.01). The incidence of preterm delivery was significantly lower after L-T4 intervention than in the non-intervention group (7% vs. 22.4%, P<0.05). Recommendation 3: Positive thyroid autoantibodies increase the risk of pregnancy complications such as miscarriage and preterm delivery, but there are few RCTs of interventional treatment and it is not recommended or opposed to give interventional treatment.