Analysis of clinical outcomes of frozen-thawed embryos transfer after IVF/ICSI at high altitude (3,650 metres) in Tibet

Abstract Research Question To analyze the pregnancy outcomes of in vitro fertilization frozen-thawed embryo transfer (IVF-FET) performed in a clinical setting located at an altitude of 3,650 metres in Tibet, China. Design This was a retrospective analysis of 238 infertility patients (344 treatment cycles) who underwent FET treatment at the Center for Reproductive Medicine, Xizang Fukang Hospital, Tibet. The overall clinical pregnancy rate, implantation rate, live birth rate, abortion rate and ectopic pregnancy rate were statistically analyzed. Women were categorized into two groups based on age: ≤35 years group (n=265) and >35 years group (n=79). The general characteristics and pregnancy outcomes were compared between the two groups. Results The clinical pregnancy rate, implantation rate, live birth rate, abortion rate, and ectopic pregnancy rate of the 344 FET cycles were 43.02%, 30.90%, 35.17%, 18.24%, and 1.35%, respectively. The clinical pregnancy rate (46.04% vs. 32.91%), implantation rate (33.92% vs. 21.01%), and live birth rate (38.11% vs. 25.32%) in the ≤35 years group were significantly greater than those in the >35 years group (P 0.05). Conclusion Good pregnancy outcomes can be achieved with IVF-FET in high-altitude areas (3,650 metres above sea level). Maternal age is still an important determinant of clinical pregnancy rate, implantation rate, and live birth rate of infertile patients in high-altitude areas.