Recurrent implantation failure (RIF) is a poorly defined clinical scenario marked by failure to achieve pregnancy after multiple embryo transfers. The causes and definitions of implantation failure are heterogeneous, posing limitations on study design as well as the interpretation and application of findings. Recent studies suggest a novel, personalized approach to defining RIF. Here, we review the implantation physiology and definitions of the implantation rate, failure, and RIF.

中文翻译：

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定义复发性植入失败：大量的混乱或仅仅是一种错觉？

复发性植入失败 (RIF) 是一种定义不明确的临床情况，其特征是在多次胚胎移植后未能实现妊娠。植入失败的原因和定义各不相同，对研究设计以及研究结果的解释和应用造成了限制。最近的研究提出了一种新颖的、个性化的方法来定义 RIF。在这里，我们回顾了植入生理学以及植入率、失败和 RIF 的定义。