title: Physiopathology of human embryonic implantation: clinical incidences.
abstract: Embryo implantation consists of a series of events promoting the invasion of the endometrium and then the uterine arterial system by the extra-embryonic trophoblast. In order for this semi-heterologous implantation to succeed, the endometrium has to first undergo a number of structural and biochemical changes (decidualization). The decidua's various constituents subsequently play a role in the embryonic implantation. The third step is the transformation of the uterine vascular system and the growth of the placenta, which will provide the foetoplacental unit with nutrients. Several physiopathological aspects will be discussed: 1) the implantation window, regulated by maternal and embryonic hormonal secretions and thus influenced by any defects in the latter: dysharmonic luteal phase, 21-hydroxylase block, abnormal integrin expression, 2) the successive trophoblast invasions of uterine vessels which, when defective, lead to early embryo loss or late-onset vascular pathologies, as preeclampsia, 3) the pregnancy's immunological equilibrium, with a spontaneously tolerated semi-allogeneic implant, 4) the impact of pro-coagulant factors (thrombophilia) on the pregnancy's progression, 5) the environment of the uterus, ranging from hydrosalpinx to uterine contractions. In summary, the least anatomical or physiological perturbation can interfere with human embryonic implantation - a very particular phenomenon and a true biological paradox.
authors.affiliation: Obstetric, Gynecologic and ART department, University hospital Amiens, 124 rue Camille Desmoulins, 80054 Amiens cedex 1 - France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Merviel
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Lourdel
authors.forename: Rosalie
authors.initials: R
authors.lastname: Cabry
authors.forename: Véronique
authors.initials: V
authors.lastname: Boulard
authors.forename: Mélanie
authors.initials: M
authors.lastname: Brzakowski
authors.forename: Pauline
authors.initials: P
authors.lastname: Demailly
authors.forename: Françoise
authors.initials: F
authors.lastname: Brasseur
authors.forename: Henri
authors.initials: H
authors.lastname: Copin
authors.forename: Aviva
authors.initials: A
authors.lastname: Devaux
mesh_terms: D010064:Embryo Implantation; D004717:Endometrium / Q000378:metabolism; D006801:Humans; D015994:Incidence; D010920:Placenta; D014327:Trophoblasts