OBJECTIVE: To compare the effects of different protocols of controlled ovarian hyperstimulation on thyroid function with those of the natural menstrual cycle. STUDY DESIGN: Prospective controlled study. SETTING: University Medical Center. PATIENTS: A total of 97 women without a history of endocrine disease undergoing intrauterine insemination either in a natural cycle, or with mild ovarian hyperstimulation, or in vitro fertilization (IVF). MAIN OUTCOME MEASURES: estradiol (E2), thyroxine binding globulin (TBG), free thyroxine (FT4), total thyroxine (TT4) and thyroid stimulating hormone (TSH) during the midluteal phase. RESULTS: In the IVF group midluteal E2, TBG, and TT4 were significantly higher; midluteal FT4 was significantly lower (mean difference: -1.46 pmol/L; P < 0.001) and midluteal TSH was significantly higher (mean difference: 0.52 mU/L; P = 0.015). CONCLUSIONS: Ovarian hyperstimulation in IVF is associated with lower midluteal FT4. and higher midluteal TSH levels compared to the natural cycle.

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doi.org/10.4137/RBi.s13450, hdl.handle.net/1765/69233
Reproductive Biology Insights
Department of Gynaecology & Obstetrics

Fleischer, K, Muller, A.F, Hohmann, F.P, de Jong, F.H, Eijkemans, M.J.C, Fauser, B.C.J.M, & Laven, J.S.E. (2014). Impact of controlled ovarian hyperstimulation on thyroid function. Reproductive Biology Insights, 7(1), 9–16. doi:10.4137/RBi.s13450