A Randomized Trial of Endometrial Scratching before In Vitro Fertilization

BACKGROUND Endometrial scratching (with the use of a pipelle biopsy) is a technique proposed to facilitate embryo implantation and increase the probability of pregnancy in women undergoing in vitro fertilization (IVF). METHODS We conducted a pragmatic, multicenter, open-label, randomized, controlled trial. Eligible women were undergoing IVF (fresh-embryo or frozen-embryo transfer), with no recent exposure to disruptive intrauterine instrumentation (e.g., hysteroscopy). Participants were randomly assigned in a 1: 1 ratio to either endometrial scratching (by pipelle biopsy between day 3 of the cycle preceding the embryo-transfer cycle and day 3 of the embryo-transfer cycle) or no intervention. The primary outcome was live birth. RESULTS A total of 1364 women underwent randomization. The frequency of live birth was 180 of 690 women (26.1%) in the endometrial-scratch group and 176 of 674 women (26.1%) in the control group (adjusted odds ratio, 1.00; 95% confidence interval, 0.78 to 1.27). There were no significant between-group differences in the rates of ongoing pregnancy, clinical pregnancy, multiple pregnancy, ectopic pregnancy, or miscarriage. The median score for pain from endometrial scratching (on a scale of 0 to 10, with higher scores indicating worse pain) was 3.5 (interquartile range, 1.9 to 6.0). CONCLUSIONS Endometrial scratching did not result in a higher rate of live birth than no intervention among women undergoing IVF.