At day 7-8 postconception, the blastocyst has completely crossed the epithelium and is embedded within the endometrium. The developing embryo is completely surrounded by the growing placenta, which at that stage consists of the two fundamental subtypes of the tro-phoblast. The multinucleated syncytiotrophoblast is in direct contact with maternal tissues, while the mononu-cleated cytotrophoblast as the stem cell layer of the trophoblast is directed towards the embryo.
All of the differentiation and developmental stages of the placenta described so far take place before fluid-filled spaces within the syncytiotrophoblast can be detected. This is why this stage is termed prelacunar stage.
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Once your pregnancy is over and done with, your baby is happily in your arms, and youre headed back home from the hospital, youll begin to realize that things have only just begun. Over the next few days, weeks, and months, youre going to increasingly notice that your entire life has changed in more ways than you could ever imagine.