Diedrich K, Fauser B C J M, Devroey P, Griesinger G
Department of Obstetrics and Gynecology, University Hospital Schleswig-Holstein, Campus Lübeck, 23538 Luebeck, Germany.
Hum Reprod Update. 2007 Jul-Aug;13(4):365-77. doi: 10.1093/humupd/dmm011. Epub 2007 Jun 4.
Despite many advances in assisted reproductive technologies (ART), implantation rates are still low. The process of implantation requires a reciprocal interaction between blastocyst and endometrium, culminating in a small window of opportunity during which implantation can occur. This interaction involves the embryo, with its inherent molecular programme of cell growth and differentiation, and the temporal differentiation of endometrial cells to attain uterine receptivity. Implantation itself is governed by an array of endocrine, paracrine and autocrine modulators, of embryonic and maternal origin. Implantation failure is thought to occur as a consequence of impairment of embryo developmental potential and/or impairment of uterine receptivity and the embryo-uterine dialogue. Therefore a better comprehension of implantation, and the relative importance of the factors involved, is warranted. New techniques for monitoring changes in the endometrium and/or the embryo at the level of gene regulation and protein expression may lead to the identification of better markers for implantation. Moreover, the use of predictive sets of markers may prove to be more reliable than a single marker. Continuing refinements to ART protocols, such as optimizing ovarian stimulation regimens, the timing of human chorionic gonadotrophin injection, or the timing of embryo transfer, should help to increase implantation rates further.
尽管辅助生殖技术（ART）取得了许多进展，但着床率仍然很低。着床过程需要囊胚与子宫内膜之间的相互作用，最终形成一个短暂的着床机会窗口。这种相互作用涉及胚胎及其固有的细胞生长和分化分子程序，以及子宫内膜细胞的时间分化以达到子宫接受性。着床本身受一系列胚胎和母体来源的内分泌、旁分泌和自分泌调节剂的调控。着床失败被认为是胚胎发育潜能受损和/或子宫接受性及胚胎-子宫对话受损的结果。因此，有必要更好地理解着床以及所涉及因素的相对重要性。在基因调控和蛋白质表达水平监测子宫内膜和/或胚胎变化的新技术可能会导致识别出更好的着床标志物。此外，使用预测性标志物组可能比单一标志物更可靠。对ART方案的持续改进，如优化卵巢刺激方案、人绒毛膜促性腺激素注射时间或胚胎移植时间，应有助于进一步提高着床率。
