Endometrial biopsy performed before the first in vitro fertilization does not impact the early pregnancy rate

Endometrial biopsy (EB) has been showed to increase the rate of clinical pregnancy in patients who underwent in vitro fertilization (IVF) failures. The purpose of this work was to assess the impact of an EB performed before the first in IVF on the early pregnancy rate. Be One study is a prospective, single-centre, randomized, open-label study. In this parallel study, patients were evenly split into two groups. In one group, patients underwent an EB between days 17 and 22 of the menstrual cycle that precedes the ovarian stimulation. In the other group (control), no EB was performed. The hCG-positive rate (early pregnancy rate) was evaluated on day 14 after the ovarian puncture. In total, 157 patients were randomized in the EB group and 154 patients were in the control group. The early pregnancy rate was 33.1% (52/157) in the EB group and 29.9% (46/154) in the control group (p = 0.54). Other parameters, including perforation, endometritis, or pain level were reassuring. An EB performed during the luteal phase of the menstrual cycle preceding the stimulation of the first IVF did not increase early pregnancy rate.