Optimal uterine anatomy and physiology necessary for normal implantation and placentation

The authors review aberrations of uterine anatomy and physiology affecting pregnancy outcomes with IVF. In the case of endometriosis and hydrosalpinx, pathologies outside of the uterus alter the uterine endometrium. In the case of endometriosis, Dominique de Ziegler outlines the numerous changes in gene expression and the central role of inflammation in causing progesterone resistance. With endometriosis, the absence of ovarian function inherent in deferred transfer, with or without a more lengthy suppression of ovarian function, appears to be sufficient to restore normal function of eutopic endometrium. Because laparoscopy is no longer routine in the evaluation of infertility, unrecognized endometriosis then becomes irrelevant in the context of assisted reproductive technology. With hydrosalpinx and submucus myomas, the implantation factor HOXA-10 is suppressed in the endometrium and, with myomas, even in areas of the uterus not directly affected. Daniela Galliano reviews various uterine pathologies, the most enigmatic being adenomyosis, where the endometrium also manifests many of the changes seen in endometriosis and deferred transfer with extended suppression appears to provide the best outcomes. Ettore Cicinelli's group has extensively studied the diagnosis and treatment of endometritis, and although more definitive diagnosis and care of this covert disorder may await techniques such as sequencing of the endometrial microbiome, it undoubtedly is an important factor in implantation failure, deserving our attention and treatment.