Nikas G
Department of Obstetrics & Gynecology, Karolinska Institute, Huddinge Hospital K57, S-18164 Stockholm, Sweden.
Semin Reprod Med. 2000;18(3):229-35. doi: 10.1055/s-2000-12561.
Ovulation and fertilization trigger embryonic development and endometrial differentiation by corpus luteum progesterone production. These two synchronous processes couple about 1 week later, when the blastocyst begins to implant in the now receptive endometrium (implantation window). Receptivity is a state of endometrial differentiation marked by a change in epithelial morphology: the hairy-like cell microvilli fuse to a single flower-like membrane projection called the "pinopode." Scanning electron microscopy of sequential endometrial biopsies shows that pinopodes form briefly (1-2 days), and their numbers correlate with implantation. On average, the formation of pinopodes is earlier in stimulated (days 19-20) and later in artificial (days 21-22) compared with natural cycles (days 20-21). There is, however, a wide (up to 5 days) variation between women in the cycle days on which pinopodes form. These results suggest the existence of a narrow and discrete implantation window in humans. Detection of pinopodes is a potential clinical marker to assess endometrial receptivity.
排卵和受精通过黄体产生孕酮来触发胚胎发育和子宫内膜分化。这两个同步过程在大约1周后耦合，此时囊胚开始植入已具备接受性的子宫内膜（着床窗）。接受性是子宫内膜分化的一种状态，其特征是上皮形态发生变化：毛发状的细胞微绒毛融合形成单个花状膜突起，称为“胞饮突”。对连续子宫内膜活检进行扫描电子显微镜检查显示，胞饮突短暂形成（1 - 2天），其数量与着床相关。平均而言，与自然周期（第20 - 21天）相比，在促排卵周期中胞饮突形成较早（第19 - 20天），在人工周期中较晚（第21 - 22天）。然而，不同女性之间胞饮突形成的周期天数存在很大差异（可达5天）。这些结果表明人类存在一个狭窄且离散的着床窗。检测胞饮突是评估子宫内膜接受性的一个潜在临床标志物。
