SRP328742 PRJNA747059 Differential expression of microRNAs in human endometrium after implantation of an intrauterine contraceptive device containing copper Intrauterine device containing copper placement will release a large amount of Cu2+ in uterine fluid, leading to local endometrial damage and inflammation, which is considered to be one of the causes of abnormal uterine bleeding. A large number of studies have shown that the metabolism and function of metal ions are related to the regulation of microRNA. The aims of this study were to investigate changes in endometrial microRNA levels after intrauterine device containing copper implantation and to preliminarily explore the signalling pathways involved in abnormal uterine bleeding. The subjects were fertile women, aged 25-35, without major obstetrics and gynecology diseases. Human endometrial tissues were collected before implantation or removal of intrauterine device containing copper. High-throughput microRNA sequencing was performed on human endometrial tissues. MicroRNA sequencing results showed that 72 miRNAs were differentially expressed in the endometrial tissue after the insertion of the intrauterine device containing copper.