Abstract Study question Do endometrial leucocytes and angiogenesis in the peri-implantation period from women with a history of recurrent reproductive failure predict hypertensive disorders in the subsequent pregnancy? Summary answer uNK cells, T cells, B cells and macrophages in the peri-implantation endometrium did not correlate with hypertensive disease of pregnancy in the subsequent pregnancy. What is known already Women with a history of recurrent reproductive failure are thought to have a higher risk of hypertensive disorders of pregnancy (HDP) subsequently. Immunological interactions and vascular factors in the placental bed are considered to be two important pathways for the initiation and development of HDP. However, the prognostic value of endometrial leucocytes and angiogenesis around the time of implantation in a cycle prior to conception and HDP in the subsequent pregnancy is still unclear. Study design, size, duration This is a prospective cohort study. A total of 694 women were included in this study from Jan 2019 to Jun 2023. Participants/materials, setting, methods Immunohistochemistry for vWF and multiplex immunofluorescence for endometrial leukocytes, including CD56+ uNK cells, CD3+ T cells, CD20+ B cells and CD68+ macrophages, were performed in the precisely timed LH + 7 endometrium. The subsequent pregnancy outcomes of the subjects were followed up as well. Main results and the role of chance Endometrial leukocytes including CD56+ uNK cells, CD3+ T cells, CD20+ B cells and CD68+ macrophages were found in the peri-implantation endometrium. There was no significant difference in the CD56+ uNK cells, CD3+ T cells, CD20+ B cells and CD68+ macrophages numbers percentage between women with and without gestational hypertension in the subsequent pregnancy. The median micro vessel density in women who developed gestational hypertension in the subsequent pregnancy (9.4 ± 3.1 /mm2 ) was significantly (P=0.038) lower than the MVD in those who did not (13.5 ± 4.9/mm2 ). Limitations, reasons for caution 1. It is not clear whether the uNK cell number during the peri-implantation period is reflective of those in the first trimester when spiral artery remodelling occurs. 2. This study was carried out in women with reproductive failure and the results may not apply to the general populations. Wider implications of the findings Vascularization features in the endometrium may provide prognostic value of subsequent hypertensive disease of pregnancy. Trial registration number not applicable