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Thyroid function during controlled ovarian hyperstimulation as part of in vitro fertilization
Clarisa R Gracia1, Christopher B Morse, Grace Chan
1Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA. cgracia@obgyn.upenn.edu
Fertility and Sterility
|January 21, 2012
Summary
Controlled ovarian hyperstimulation (COH) significantly elevates thyroid-stimulating hormone (TSH) and thyroid hormones. These changes, particularly in women with hypothyroidism, may impact fertility treatment outcomes.
Area of Science:
- Reproductive Endocrinology
- Thyroid Physiology
Background:
- Thyroid function is crucial for reproductive health.
- Controlled ovarian hyperstimulation (COH) involves potent hormonal stimulation.
- Potential interactions between COH and thyroid function require investigation.
Purpose of the Study:
- To precisely define the changes in thyroid function during COH.
- To identify the timing and magnitude of these thyroid alterations.
- To assess the influence of baseline thyroid status and pregnancy on these changes.
Main Methods:
- Prospective cohort study involving 57 women undergoing IVF.
- Serum thyroid hormones (TSH, free T4, TBG) and estradiol measured at six time points.
- Analysis focused on changes from baseline through 2 weeks post-pregnancy test.
Main Results:
- TSH levels increased significantly during COH, peaking post-hCG administration.
- Free T4 and thyroxine-binding globulin (TBG) also showed elevations.
- 44% of women with normal baseline TSH experienced an increase above 2.5 mIU/L during COH.
Conclusions:
- COH induces significant thyroid-stimulating hormone (TSH) elevations, potentially exceeding pregnancy-appropriate targets.
- Preexisting hypothyroidism exacerbates these thyroid function changes.
- Clinical vigilance in monitoring thyroid function during COH is warranted, especially for supplementation decisions.
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