Thyroid stimulating hormone levels rise after assisted reproductive technology.

Area of Science:

• Reproductive Endocrinology
• Thyroid Physiology

Background:

• Controlled ovarian hyperstimulation (COH) in assisted reproductive technology (ART) involves supraphysiological estradiol (E2) levels.
• The impact of these elevated E2 levels on thyroid-stimulating hormone (TSH) during ART cycles requires further elucidation.

Purpose of the Study:

• To investigate the relationship between high E2 levels during COH and subsequent changes in TSH.
• To determine if E2 fluctuations during ART cycles significantly alter TSH levels.

Main Methods:

• A cohort study of 154 women undergoing ART cycles (excluding those with known thyroid disease) at McGill University Health Center.
• Paired t-tests and multiple regression analyses were used to assess TSH changes in relation to E2 levels, anti-thyroid antibodies, and ovarian reserve.
• Missing data were managed using multiple imputation.

Main Results:

• A significant rise in TSH levels was observed as E2 levels increased from low to supraphysiological ranges during ART treatment.
• This TSH increase reached clinical significance by the time of the pregnancy test.
• Factors influencing TSH change included infertility type (male/tubal factor), ART protocol, and presence of thyroid antibodies.

Conclusions:

• TSH levels increase during ART cycles, with clinical significance noted by the pregnancy test.
• Further research is recommended to explore TSH dynamics in specific at-risk subgroups, such as individuals with thyroid antibodies or pre-existing thyroid conditions.