Abstract
BACKGROUND: Live birth rate (LBR) has been associated with ethnicity and race in Europe and the United States. However, the impact of ethnicity on LBR among multiethnic Chinese infertile women has remained unexplored. This study aims to investigate whether LBR of in vitro fertilization and embryo transfer (IVF-ET) is different between ethnic Yi and Han Chinese women. METHODS: A total of 22,450 Han and 863 Yi women aged 20~45 years undergoing the first cycle of IVF-ET at three tertiary hospitals were retrospectively enrolled in this study. The protocols of ovarian stimulation were gonadotropin-releasing hormone (GnRH) agonist and GnRH antagonist, and the primary outcome was LBR. To minimize the influence of confounding factors, 1:1 propensity score matching (PSM) analysis was carried out before the outcomes of IVF-ET were analyzed. This clinical trial was registered with the Chinese Clinical Trial Registry (Registration number: ChiCTR2300070269). RESULTS: After PSM, the rates of implantation, clinical and ongoing pregnancy, and LBR of Yi women (n = 853) were significantly lower than those of Han women (n = 853) (P < 0.05). Subgroup analyses further indicated that the impact of ethnicity on LBR was most significant in women aged 20~35 years (adjusted odds ratio (OR) = 0.77, 95% confidence interval (CI) = [0.62-0.97]) and in women with normal body mass index (adjusted OR = 0.76, 95% CI [0.58-0.98]). Multiple regression analysis revealed that age was associated with LBR in both ethnicities, while body weight may also affect LBR in Han women (P < 0.05). CONCLUSIONS: The outcomes of IVF-ET were worse in Yi women compared to Han women. Ethnicity and age are associated with LBR. Maintaining a normal weight may be beneficial for LBR, especially for ethnic Han Chinese women.