Thyroid function after controlled ovarian hyperstimulation in women with and without the hyperstimulation syndrome

Area of Science:

• Reproductive Endocrinology
• Thyroidology
• Infertility Treatment

Background:

• Controlled ovarian hyperstimulation (COH) is a key component of assisted reproductive technology (ART).
• Ovarian hyperstimulation syndrome (OHSS) is a potential complication of COH, affecting thyroid function is not well understood in euthyroid women.
• Understanding thyroid function during COH and OHSS is crucial for patient management.

Purpose of the Study:

• To investigate the impact of OHSS on thyroid function in women without pre-existing thyroid disorders.
• To compare thyroid function changes between women who develop OHSS and those with uncomplicated COH.
• To assess serum TSH and free T4 levels in relation to COH and OHSS.

Main Methods:

• Retrospective analysis of 77 women undergoing COH at a tertiary fertility center.
• Exclusion of women with thyroid disorders; inclusion of only pregnant women post-ART.
• Measurement of serum TSH, free T4 (fT4), thyroid peroxidase, and thyroglobulin antibodies before and after embryo transfer (ET).

Main Results:

• Both OHSS and no-OHSS groups showed comparable increases in serum TSH and fT4 levels 2 weeks post-ET compared to baseline.
• In the OHSS group, TSH increased from 1.9 ± 0.8 to 3.1 ± 1.9 mIU/L and fT4 from 12.3 ± 1.4 to 13.4 ± 2.1 ng/L.
• In the no-OHSS group, TSH increased from 2.1 ± 1.1 to 2.6 ± 1.9 mIU/L and fT4 from 13.0 ± 1.7 to 13.8 ± 1.6 ng/L.

Conclusions:

• Serum TSH levels increased significantly after COH in women without thyroid disorders, irrespective of OHSS development.
• The thyroid function response, specifically TSH and fT4 levels, was comparable between women with and without OHSS.
• OHSS does not appear to significantly alter thyroid function in euthyroid women undergoing COH.