Antithyroid antibodies may predict serum beta HCG levels and biochemical pregnancy losses in euthyroid women with IVF single embryo transfer

To investigate the relationship between thyroid autoimmunity and early pregnancy serum β-HCG levels in intracytoplasmic sperm injection patients.The study subjects were 85 female euthyroid patients undergoing intracytoplasmic sperm injection embryo transfer cycles with GnRH antagonist treatment. Patients who received transfer of more than one embryo, those with serum TSH levels of greater than 2.5 IU/ml and subjects using levothyroxine were excluded. Normal responder patients under the age of 40 years were randomly selected from the patient files retrospectively. Subjects were divided into two groups: those with autoimmune thyroid disease (thyroid autoimmunity group; n = 39) and those without the disease (control group; n = 46).The age, body mass index, trial number, total rFSH treatment dose, the number of cumulus oophorus complexes, number of metaphase II oocytes, and number of 2-pronuclei embryos were similar in the thyroid autoimmunity and control groups. Serum β-HCG levels measured on the 14th day after oocyte pickup were significantly lower in the thyroid autoimmunity group than in the control group (93.8 ± 35.8 versus 128.5 ± 55.8 mlU/ml, respectively; p < .001). The miscarriage rate was higher in the thyroid autoimmunity group than in the control group (34.4% versus 21.7%, respectively; p = .034).We found that early-stage pregnancy serum β-HCG hormone levels among euthyroid patients undergoing intracytoplasmic sperm injection were lower in subjects with thyroid autoimmunity than in those without thyroid autoimmunity. This result, reported for the first time in the literature on euthyroid pregnant women with thyroid autoimmunity, may be predictor of early pregnancy losses in pregnant women with thyroid autoimmunity.Key messageIn intracytoplasmic sperm injection (ICSI)/IVF patients, due to lack of evidence-based data about the relationship between thyroid autoimmunity and pregnancy loss the current research was conducted. Early-stage pregnancy serum β-HCG hormone levels in euthyroid ICSI patients with thyroid autoimmunity are lower than those without autoimmunity which may be associated with early pregnancy losses.