Great obstetrical syndromes
Moshe Hod, Vincenzo Berghella, Mary E. D'Alton, Gian Carlo Di Renzo, Eduard Gratacós, Vassilios Fanos in New Technologies and Perinatal Medicine, 2019
In human pregnancy, embryo implantation is initiated by apposition of the blastocyst with its embryonic pole, bearing the inner cell mass, to the endometrial epithelium. While the inner cell mass gives rise to the embryo, the outer cell mass—referred to as trophoblast cells—forms the wall of the blastocyst, thus mediating initial adherence to the uterine wall and later forming the placenta. Apposition and adherence of the blastocyst are followed by intercellular fusion of trophoblasts that are in contact with the endometrial epithelium, to form the multinucleated syncytiotrophoblast (9). At that very early stage of embryo implantation, the syncytiotrophoblast is equipped with an enzymatic endowment that enables crossing of the endometrial epithelium and penetration of the underlying stroma. The endometrium from now on may be referred to as decidua, which provides the breeding ground for the growing embryo and the developing placenta. Once the blastocyst has completely penetrated the decidua, the mass of syncytiotrophoblast rapidly increases by ongoing proliferation and fusion of underlying cytotrophoblasts. The syncytiotrophoblast forms a complete layer over the surface of the blastocyst, whereas the site at the implantation pole achieves considerable thickness and develops extensions that deeply invade the decidua.
Ultrasound in the First Trimester
Asim Kurjak in CRC Handbook of Ultrasound in Obstetrics and Gynecology, 2019
As the chorionic sac grows and protrudes further into the uterine cavity, the decidua can be divided into three parts: the decidua basalis, the decidua capsularis, and the decidua parietalis. The decidua basalis is a part underlying the embryo and forming the maternal component of the placenta, the decidua capsularis covers the chorionic sac, while the remaining endometrium covering the uterine cavity is the decidua parietalis. The chorion frondosum and the underlying decidua basalis form the definitive placental site. The space between the decidua capsularis and parietalis usually contains mucus and sometimes a small amount of blood (implantation bleeding) (Figure 11). For this reason the triangular space can be ultrasonically visualized as a small, triangular echo-free or echo-poor area adjacent to the gestational sac (Figures 12 and 13), or as an echo-free rim surrounding the gestational sac (Figure 14). The latter appearance, greatly depending on the orientation and angulation of the transducer, is also erroneously called “double sac sign” and can be used as a differential sign distinguishing the normal gestational sac from the pseudogestational sac of ectopic pregnancy.16
Regulation of Reproduction by Dopamine
Nira Ben-Jonathan in Dopamine, 2020
The human decidua represents the maternal part of the placenta. It is composed of the decidua basalis, which interacts with the trophoblast; the decidua capsularis, which grows over the embryo on the luminal side; and the decidua parietalis, which fuses with the decidua capsularis by the fourth month of gestation. The placenta connects the developing fetus to the uterus to allow nutrient uptake, thermoregulation, waste elimination, and gas exchange via the maternal blood supply. It also protects the fetus from infection and immune rejection, and produces hormones that support the pregnancy. The human placenta is classified as hemochorial because the chorionic epithelium is in direct contact with the maternal blood. The placenta is one of the organs with the highest evolutionary diversity among animal species, and no animal models exactly represents human placentation [85].
Diverse endometrial mRNA signatures during the window of implantation in patients with repeated implantation failure
Published in Human Fertility, 2018
Cheng Shi, Hong Jing Han, Li Juan Fan, Jing Guan, Xing Bang Zheng, Xi Chen, Rong Liang, Xiao Wei Zhang, Kun Kun Sun, Qing Hua Cui, Huan Shen
The top 10 up- and down-regulated mRNAs could be allocated to six groups based on their participation in the biological process of establishing endometrial receptivity and their reported relationship to implantation or pregnancy. The first group was related to decidualization, including ABP1 and IGFBP1. Formation of a functional decidua via decidualization is indispensable for a successful pregnancy, and defects in this process may be associated with infertility and miscarriage (Otti et al., 2014). Amiloride binding protein 1 (ABP1) is a membrane-associated amine oxidase which mainly metabolizes histamine and putrescine. Studies on mice revealed this gene to be regulated by oestrogen and to play a crucial role in embryo implantation by participating in decidualization (Liang et al., 2010). It was also reported to be up-regulated during the WOI of fertile women (Bhagwat et al., 2013). This indicates that decidualization may not have occurred if the expression of ABP1 is reduced, since this may finally contribute to implantation failure, since it was down-regulated in the RIF group. Insulin-like growth factor binding protein 1 (IGFBP-1) is secreted by well differentiated decidua cells, making it one of the key markers for decidualization (Kim, Buzzio, Li, & Lu, 2005). It was found to be highly expressed in the WOI endometrium from fertile women and down-regulated in unexplained infertile women (Altmae et al., 2010). We found that IGFBP-1 was down-regulated, consistent with the hypothesis that poor decidualization may have a negative effect on embryo implantation and finally result in implantation failure.
Incorporating placental tissue in cord blood banking for stem cell transplantation
Published in Expert Review of Hematology, 2018
Luciana Teofili, Antonietta R. Silini, Maria Bianchi, Caterina Giovanna Valentini, Ornella Parolini
The human term placenta is a round-shaped, feto-maternal organ that has variable diameters (15–20 cm) and thicknesses (2–3 cm). The fetal part of the placenta is composed of the placental disk, the amniotic and chorionic membranes (often referred to as the fetal membranes), and the umbilical cord. The maternal side is comprised of the decidua, which is derived from the maternal endometrium [1]. The placental disk consists of a chorionic plate and a basal plate, which together form a base and a cover, respectively, to enclose the intervillous space, and is surrounded by the fetal membranes, which closely adhere to each other and form the amniotic sac. The amniotic membrane (AM) is a thin, avascular sheet comprised of epithelial and stromal layers [2]. The ectodermal-derived amniotic epithelium is composed of a single layer of flat, cuboidal, or columnar epithelial cells uniformly arranged on a basement membrane [1]. The amniotic epithelium also covers the umbilical cord, which is composed of one umbilical vein and two umbilical arteries embedded in a gelatinous proteoglycan-rich matrix called Wharton’s jelly (WJ). The amniotic stroma derives from mesoderm and consists of a collagen-rich acellular compact layer with widely dispersed fibroblast-like cells and rare macrophages. The chorion is the outermost membrane of the sac enclosing the fetus, and is comprised of the chorionic stromal and trophoblastic layers, which include extravil-cytotrophoblast cells [3].
Phenotypic Switch of Endovascular Trophoblasts in Decidual Vasculopathy with Implication for Preeclampsia and Other Pregnancy Complications
Published in Fetal and Pediatric Pathology, 2021
CD56 expression on the vasculopathy present in the membrane roll was examined, in addition to immunostaining for CD68 and pancytokeratin (AE1/AE3) (Fig. 3). The endovascular cells within the decidua capsularis (membrane roll) are negative for CD56 and AE1/AE3 but strongly positive for CD68, indicating the macrophage cell origin. This is consistent with the traditional view that the endovascular cells within the decidual vasculopathy are inflammatory cells (leukocytes/macrophages), in contrast to the endovascular trophoblasts with CD56 expression described above at the decidua basalis. It appears that the mechanisms of vasculopathy development in decidua basalis are different from that in decidua capsularis, although the morphologic features of vasculopathy in both locations are identical.
Related Knowledge Centers
- Mucous Membrane
- Myometrium
- Placenta
- Progesterone
- Embryo
- Trophoblast
- Endometrium
- Uterus
- Pregnancy
- Placenta Accreta Spectrum