title: Introduction: Examining the many potential reasons why euploid blastocysts do not always result in viable pregnancies (and deliveries): part 2.
abstract: To result in a viable delivery: 1) a capable embryo must be accurately deposited and retained in an optimal location of the uterine cavity; 2) the endometrium must be receptive and synchronized to the developmental stage of the embryo; 3) the uterus must be physiologically and anatomically adequate; and 4) there should not be the presence of circulating factors capable of disrupting normal implantation and placentation, nor the absence of specific factors required for endometrial receptivity. The intricate interaction between the embryo and the uterus is discussed in this series of reviews.
authors.affiliation: Reproductive Partners San Diego, Division of Reproductive Endocrinology and Infertility, Department of Reproductive Medicine, University of California, San Diego, California. Electronic address: drmeldrum@gmail.com.
authors.forename: David R
authors.initials: DR
authors.lastname: Meldrum
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Medicine, Université Paris Descartes, Paris Sorbonne Cité-Assistance Publique Hôpitaux de Paris, CHU Cochin, Paris, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: de Ziegler
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D036861:Delivery, Obstetric / Q000639:trends*; D010064:Embryo Implantation / Q000502:physiology; D005260:Female; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome
keywords: Implantation; embryo transfer; embryo-endometrial synchrony; endometrial receptivity; uterine factors