The goal of this clinical trial is to investigate the influence of thyroxine supplementation on pregnancy outcomes in women with varying levels of Thyroid-Stimulating Hormone (TSH), who have experienced recurrent pregnancy loss in the first trimester. The main questions it aims to answer are:

• Does thyroxine treatment improve pregnancy outcomes in women with TSH levels between 2.5 mU/L and 4 mU/L?
• Is the effect of thyroxine treatment different in women with TSH levels higher than 4 mU/L?

Participants will be grouped based on their TSH levels, into two groups - those with TSH levels between 2.5 mU/L and 4 mU/L, and those with TSH levels higher than 4 mU/L. They will then be given thyroxine treatment.

Researchers will compare these two groups to see if the pregnancy outcomes differ based on the different TSH levels and thyroxine treatment.

This is a prospective clinical trial that aims to investigate the impact of thyroxine supplementation on the outcomes of pregnancies in women who have experienced recurrent pregnancy loss in the first trimester. The study will specifically focus on the role of Thyroid-Stimulating Hormone (TSH) levels in these outcomes.

Participants in the study will include women who have suffered recurrent pregnancy loss in the first trimester and exhibit varying levels of TSH. For the purpose of this research, these participants will be categorized into two groups based on their TSH levels: the first group will consist of women with TSH levels between 2.5 mU/L and 4 mU/L, and the second group will include those with TSH levels higher than 4 mU/L.

All participants will receive thyroxine treatment, with dosages and treatment plans as determined by their respective healthcare providers. The main purpose of this trial is to examine two key questions:

Does thyroxine treatment lead to improved pregnancy outcomes in women with TSH levels between 2.5 mU/L and 4 mU/L? How does the effect of thyroxine treatment on pregnancy outcomes differ in women with TSH levels higher than 4 mU/L? The primary outcomes of interest in this study will be pregnancy success rates, defined as a viable pregnancy beyond the first trimester. Secondary outcomes might include measurements such as gestational age at delivery, birth weight, and any complications that may arise during pregnancy.

This trial aims to provide valuable insights into the potential benefits of thyroxine treatment for women with varying levels of TSH who have experienced recurrent pregnancy loss. The results could contribute to the development of more effective treatment protocols and ultimately improve pregnancy outcomes for these women.

Inclusion Criteria:

• Women aged 18 to 40 years old.
• Diagnosis of recurrent pregnancy loss, defined as two or more pregnancy losses in the first trimester.
• Confirmed thyroid function test results with TSH levels either between 2.5 and 4 or higher than 4.
• Willing and able to give informed consent for participation in the study.

Exclusion Criteria:

• Women who are currently taking thyroid medication before the study starts.
• Presence of other causes of recurrent pregnancy loss such as antiphospholipid syndrome, uterine abnormalities, genetic/chromosomal disorders, etc.
• Presence of other severe chronic diseases like heart disease, kidney disease, uncontrolled diabetes, etc.
• Known allergy or intolerance to thyroxine.