###Human: I am having IVF failure even though there are good stimulation and embryo production. Why? ###Assistant: Hello. I completely empathize with you and understand your concerns here. The primary step where, in your case, things could have gone wrong is the stage of implantation over a non-receptive endometrium of the uterus when a top grade blastocyst is being transferred and each time there is a negative result. The implantation at endometrium is the issue in your case, most likely.  Few things are important for a good endometrium. The endometrial thickness should be more than 9 mm at ET. Good endometrial blood flow in zone 2, 3 and 4 to check for receptivity through transvaginal Doppler study in the mid-cycle before embryo transfer. Before even contemplating IVF, an endometrial biopsy for histopathology report should be obtained to rule out any pre-existent endometritis or and acid-fast bacillus (tuberculous cause). The malefactor is taken care of by ICSI and IVF and hence a high-grade blastocyst is being achieved for transfer. I would like you to share with me the last IVF cycle medicinal protocol, scans, follicular monitoring reports and if possible reports of endometrial biopsy for a histopathology, pap smear report, high vaginal swab culture (if any) for further study and check to ascertain what went wrong in your case.