Human ReproductionEndometrial Scratching in Patients with Unexplained Infertility Who Have a Good Prognosis for Natural Conception: A Randomized Controlled Trial (SCRaTCH-OFO)

Published September 29, 2026, this open-label trial randomized 593 patients across 31 Dutch centers to one endometrial scratch or no intervention. Participants were aged 18–38 with unexplained infertility and Hunault scores of at least 30%. The primary outcome was pregnancy within 12 months leading to live birth. Both groups initially pursued expectant management, but subsequent fertility treatment contributed to outcomes. The primary comparison did not demonstrate benefit; incomplete recruitment limits precision rather than establishing equivalence.

Clinical Considerations

• Reported ITT results: 188/294 versus 168/294 live births; RR 1.12 (95% CI 0.98–1.28), P=0.09; reported risk difference +6.8% (−1.1% to +14.7%).
• Recruitment stopped below the planned 792 participants; per-protocol and smoking-adjusted analyses also remained nonsignificant.
• Approximately 45% in each arm started fertility treatment during follow-up; cumulative live births are not exclusively natural-conception outcomes.
• Scratch timing was not randomized. The exploratory follicular-phase comparison, P=0.05, is hypothesis-generating; luteal-phase participants also lost a conception opportunity.
• No severe complications were reported, but bleeding and abdominal pain occurred; five procedures were unsuccessful or too painful.
• The unblinded, no-sham design permits performance bias; findings do not establish efficacy in poorer-prognosis patients or IVF populations.

Practice Applications

• Discuss that this trial does not support routine scratching in the studied population, while acknowledging that its confidence interval permits clinically meaningful benefit.
• Avoid presenting the numerical difference as proven improvement or the timing subgroup as a basis for choosing follicular-phase scratching.
• Recognize procedural burden and distinguish cumulative live birth from natural conception when counseling about fertility add-ons.