Effect of TSH on oocyte maturation of PCOS patients with normal thyroid function in IVF

BACKGROUND: The serum TSH level of PCOS patients was higher than that of the general female population. For patients with thyroid dysfunction, the abnormal TSH level is negatively related to the outcomes of assisted reproductive technology, but for PCOS patients with normal thyroid function, the effect of TSH level on outcomes of in vitro fertilization has not been reported. In this study, PCOS patients with normal thyroid function were included in this study to evaluate the effect of TSH on the outcomes of IVF-ET. METHODS: A retrospective cohort study was conducted to analyze the clinical data of 3190 patients who underwent IVF-ET in the Department of Human Reproductive Center of Renmin Hospital Hubei University of Medicine from January 2017 to July 2021, including 594 PCOS patients and 2595 non PCOS patients. The IVF-ET outcomes between the two groups were compared; Multi-factor linear regression analysis was used to analyze the correlation between the related variables and the oocyte maturation of PCOS patients; The ROC curve of the effect of TSH on oocyte maturation in PCOS patients was drawn. The PCOS patients were divided into TSH < 2.98 group (n = 454) and TSH ≥ 2.98 group (n = 141) according to ROC threshold TSH 2.98, and the outcomes were compared. RESULTS: TSH level in PCOS group was significantly higher than that in non-PCOS group (2.42 ± 0.86 vs 2.00 ± 0.89 UU / ml, P < 0.01), and the oocyte maturation rate and 2PN fertilization rate in PCOS group were lower than those in non-PCOS group (90.9% vs 92.4%, P = 0.02) (84.57% vs 86.77%, P = 0.02). There was no significant difference in cleavage rate and high-quality embryo rate between the two groups (P > 0.05); There was no difference in clinical pregnancy rate, abortion rate, ectopic pregnancy rate and live birth rate between the two groups (P > 0.05). Multi-factor linear regression analysis showed that TSH was negatively correlated with oocyte maturation in PCOS patients [β = -0.124, P = 0.013,95%CI (-0.027 ~ -0.003)]; The oocyte maturation rate in TSH < 2.98 group was significantly higher than that in TSH ≥ 2.98 group (91.7% vs 88.2%, P = 0.001). CONCLUSION: The TSH level of PCOS patients with normal thyroid function is higher than that of normal people, and it is negatively correlated with the oocyte maturation in in-vitro fertilization. The ROC curve showed that when TSH > 2.98uIU/ml, the possibility of immature oocytes was higher (specificity 28.9%, sensitivity 83.0%).