In vitro fertilization add-ons for the endometrium: it doesn't add-up.

The probability of live birth from an in vitro fertilization (IVF) cycle is modest. Many additional treatments (add-ons) are available which promise to improve the success of IVF. This review summarizes the current evidence for common IVF add-ons which are suggested to improve endometrial receptivity. Systematic reviews of randomized controlled trials and individual trials were included. Five add-ons were included: immune therapies, endometrial scratching, endometrial receptivity array, uterine artery vasodilation, and human chorionic gonadotropin instillation. The results suggest there is no robust evidence that these add-ons are effective or safe. Many IVF add-ons are costly, consuming precious resources which may be better spent on evidence-based treatments or further IVF. Large randomized controlled trials and appropriate safety assessment should be mandatory before the introduction of IVF add-ons into routine practice.