Endocrine Causes of Implantation Failure

Achieving successful implantation requires a complex endocrine stimulus of the endometrium. A deep understanding of this highly coordinated process is required for clinicians and investigators attempting to optimize an individual patient’s likelihood of success. Our current level of knowledge is the result of many elegant studies to elucidate these mechanisms. However, our tools for assessing the proper functioning of the endometrium in relation to hormonal response are limited. Modern infertility therapies that rely on gonadotropin stimulation undoubtedly change the chronology and histology of endometrium response. However, many patients achieve success despite these alterations. Patients with recurrent implantation failure, however, may be more sensitive to forces which change the normal physiologic state. Thus, careful attention to these issues in these patients is paramount. This chapter attempts to lay the groundwork for a comprehensive understanding of normal endometrial response, assess current diagnostic options and their limitations, and describe how pathological processes can disrupt normal implantation.