P-659 Does Preconception thyroid-stimulating hormone (TSH) levels affect the clinical outcomes of Infertile Women Undergoing Fresh Embryo Transfer Cycle?

Abstract Study question Does Preconception TSH levels affect the clinical outcomes of Infertile Women Undergoing Fresh Embryo Transfer Cycle? Summary answer Among euthyroid patients, preconceptional TSH values in the high-normal range (between 2.5 and 4.0 mIU/L) are associated with adverse clinical outcomes. What is known already Serum thyroid-stimulating hormone (TSH) levels are routinely screened in women with infertility given the negative impact of thyroid disease on ovarian function and pregnancy is associated with poor outcomes.In fact, an underlying thyroid abnormality was found in 46% for women experiencing IVF failure and TSH levels were inversely proportional to the fertilization rate at IVF. While it is clear that pregnancies complicated by subclinical hypothyroidism in the fertile population have poor outcomes, the relevance of preconception subclinical hypothyroidism in infertile patients undergoing ART has not been thoroughly examined. Study design, size, duration Outcomes of all fresh IVF patients with an embryo transfer from from January 2019 to August 2021 within 1 yr of TSH screening at a our center were studied. IVF cycles using donor oocyte, TESE sperm, PGT, or those lacking follow-up were excluded. For patients with more than one Preconception TSH measurement prior IVF, the most recent measurement before the IVF cycle was used. Participants/materials, setting, methods Cycles were categorized into two groups based on preconceptional TSH values: Euthyroid (0.4–2.5 μIU/mL), subclinical hypothyroidism (>2.5-4.0 μIU/mL). All women underwent standard IVF protocols following usual individualized practice in our IVF clinic. Chi-square test was used to evaluate the differences between the patient cohorts. Main results and the role of chance A total of 2,669 fresh-ET cycles were reviewed retrospectively by dividing them into a euthyroid group (0.4-2.5 uIU/mL, n = 2397) and subclinical hypothyroidism group (2.5-4.0 uIU/mL, n=272). The overall biochemical pregnancy rate and clinical pregnancy rate was significantly lower in women with subclinical hypothyroidism (50.0% vs 43.4%, 40.0% vs 30.9%, p < 0.05). However, biochemical preganacy loss rate and the miscarriage rate was higher in women with subclinical hypothyroidism. (19.6% vs. 28.8%, 17.3% vs. 25.0%, p = 0.079) Limitations, reasons for caution This is a retrospective study and results must be confirmed on a well-designed randomized controlled study. Correlations must be considered with caution since the role of TSH is under study, especially when considering LBR outcome. Wider implications of the findings Among euthyroid patients, preconceptional TSH values in the high-normal range (between 2.5 and 4.0 mIU/L) are associated with adverse clinical outcomes. Our findings suggest that subclinical hypothyroidism may affect clinical outcomes. Trial registration number not applicable