Talk:Placenta Development

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Cite this page: Hill, M.A. (2024, March 28) Embryology Placenta Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Placenta_Development

Original Pages

Related Pages: Villi Development | Maternal Decidua | Placental Abnormalities | Stage 13/14 | Stage22 | Placental Histology | [Placental Vascular Beds | Blood | Blood Vessels | Birth | Stem Cells - Cord Blood

Placenta Links: Placenta - Villi Development | Placenta - Maternal Decidua | Placenta - Abnormalities | Placenta - Stage 13/14 | Placenta - Histology | Placenta - Stage22 | Placenta - Vascular Beds

Placental Abnormalities

  • placenta accreta one abnormally adherent to the myometrium, with partial or complete absence of the decidua basalis.
  • battledore placenta one with the umbilical cord inserted at the edge.
  • placenta circumvallata (circumvallate placenta) one encircled with a dense, raised, white nodular ring, the attached membranes being doubled back over the edge of the placenta.
  • placenta fenestrata one that has spots where placental tissue is lacking.
  • placenta increta placenta accreta with penetration of the myometrium.
  • placenta membranacea one that is abnormally thin and spread over an unusually large area of the myometrium.
  • placenta percreta placenta accreta with invasion of the myometrium to the peritoneal covering, sometimes causing rupture of the uterus.
  • placenta previa low implantation of the placenta so that it partially or completely covers the cervical os. Percentages are used to designate the amount of obstruction; e.g., 100 per cent is total placenta previa, and 50 per cent indicates that about half the opening is obstructed. The condition occurs with greater frequency in women who have had multiple pregnancies or are over 35. The exact cause is not known.

2012

The discovery of placenta growth factor and its biological activity

Exp Mol Med. 2012 Jan 31;44(1):1-9.

De Falco S. Source Angiogenesis Laboratory and Stem Cell Fate Laboratory Institute of Genetics and Biophysics 'Adriano Buzzati-Traverso' - CNR - Via Pietro Castellino 111, 80131 Napoli, Italy.

Abstract

Angiogenesis is a complex biological phenomenon crucial for a correct embryonic development and for post-natal growth. In adult life, it is a tightly regulated process confined to the uterus and ovary during the different phases of the menstrual cycle and to the heart and skeletal muscles after prolonged and sustained physical exercise. Conversly, angiogenesis is one of the major pathological changes associated with several complex diseases like cancer, atherosclerosis, arthritis, diabetic retinopathy and age-related macular degeneration. Among the several molecular players involved in angiogenesis, some members of VEGF family, VEGF-A, VEGF-B and placenta growth factor (PlGF), and the related receptors VEGF receptor 1 (VEGFR-1, also known as Flt-1) and VEGF receptor 2 (VEGFR-2, also known as Flk-1 in mice and KDR in human) have a decisive role. In this review, we describe the discovery and molecular characteristics of PlGF, and discuss the biological role of this growth factor in physiological and pathological conditions.

PMID 22228176

Recruitment of 5' Hoxa genes in the allantois is essential for proper extra-embryonic function in placental mammals

Development. 2012 Jan 4. [Epub ahead of print] Scotti M, Kmita M.

Abstract

The Hox gene family is well known for its functions in establishing morphological diversity along the anterior-posterior axis of developing embryos. In mammals, one of these genes, Hoxa13, is crucial for embryonic survival, as its function is required for the proper expansion of the fetal vasculature in the placenta. Thus, it appears that the developmental strategy specific to placental mammals is linked, at least in part, to the recruitment of Hoxa13 function in developing extra-embryonic tissues. Yet, the mechanism underlying this extra-embryonic recruitment is unknown. Here, we provide evidence that this functional novelty is not exclusive to Hoxa13 but is shared with its neighboring Hoxa11 and Hoxa10 genes. We show that the extra-embryonic function of these three Hoxa genes stems from their specific expression in the allantois, an extra-embryonic hallmark of amniote vertebrates. Interestingly, Hoxa10-13 expression in the allantois is conserved in chick embryos, which are non-placental amniotes, suggesting that the extra-embryonic recruitment of Hoxa10, Hoxa11 and Hoxa13 most likely arose in amniotes, i.e. prior to the emergence of placental mammals. Finally, using a series of targeted recombination and transgenic assays, we provide evidence that the regulatory mechanism underlying Hoxa expression in the allantois is extremely complex and relies on several cis-regulatory sequences.

PMID 22219351


2011

miR-16 and miR-21 Expression in the Placenta Is Associated with Fetal Growth

Maccani MA, Padbury JF, Marsit CJ.

PLoS One. 2011;6(6):e21210. Epub 2011 Jun 15.

Source Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, United States of America.

Abstract

BACKGROUND: Novel research has suggested that altered miRNA expression in the placenta is associated with adverse pregnancy outcomes and with potentially harmful xenobiotic exposures. We hypothesized that aberrant expression of miRNA in the placenta is associated with fetal growth, a measurable phenotype resulting from a number of intrauterine factors, and one which is significantly predictive of later life outcomes. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed 107 primary, term, human placentas for expression of 6 miRNA reported to be expressed in the placenta and to regulate cell growth and development pathways: miR-16, miR-21, miR-93, miR-135b, miR-146a, and miR-182. The expression of miR-16 and miR-21 was markedly reduced in infants with the lowest birthweights (p<0.05). Logistic regression models suggested that low expression of miR-16 in the placenta predicts an over 4-fold increased odds of small for gestational age (SGA) status (p = 0.009, 95% CI = 1.42, 12.05). Moreover, having both low miR-16 and low miR-21 expression in the placenta predicts a greater increase in odds for SGA than having just low miR-16 or miR-21 expression (p<0.02), suggesting an additive effect of both of these miRNA. CONCLUSIONS/SIGNIFICANCE: Our study is one of the first to investigate placental miRNA expression profiles associated with birthweight and SGA status. Future research on miRNA whose expression is associated with in utero exposures and markers of fetal growth is essential for better understanding the epigenetic mechanisms underlying the developmental origins of health and disease.

PMID: 21698265 http://www.ncbi.nlm.nih.gov/pubmed/21698265

http://www.mirbase.org/

2010

Placental surface shape, function, and effects of maternal and fetal vascular pathology

Placenta. 2010 Oct 6. [Epub ahead of print]

Salafia CM, Yampolsky M, Misra DP, Shlakhter O, Haas D, Eucker B, Thorp J.

Placental Analytics, LLC, 93 Colonial Avenue, Larchmont, NY 10538, USA; Department of Obstetrics and Gynecology and Pediatrics, New York Methodist Hospital, Brooklyn, NY, USA. Abstract

GOAL: In clinical practice, variability of placental surface shape is common. We measure the average placental shape in a birth cohort and the effect deviations from the average have on placental functional efficiency. We test whether altered placental shape improves the specificity of histopathology diagnoses of maternal uteroplacental and fetoplacental vascular pathology for clinical outcomes.

MATERIALS AND METHODS: 1225 Placentas from a prospective cohort had chorionic plate digital photographs with perimeters marked at 1-2 cm intervals. After exclusions of pre-term (n = 202) and velamentous cord insertion (n = 44), 979 (95.7%) placentas were analyzed. Median shape and mean perimeter were estimated. The relationship of fetal and placental weight was used as an index of placental efficiency termed "β". The principal placental histopathology diagnoses of maternal uteroplacental and fetoplacental vascular pathologies were coded by review of individual lesion scores. Acute fetal inflammation was scored as a "negative control" pathology not expected to affect shape. ANOVA with Bonferroni tests for subgroup comparisons were used.

RESULTS: The mean placental chorionic shape at term was round with a radius estimated at 9.1 cm. Increased variability of the placental shape was associated with lower placental functional efficiency. After stratifying on placental shape, the presence of either maternal uteroplacental or fetoplacental vascular pathology was significantly associated with lower placental efficiency only when shape was abnormal.

CONCLUSIONS: Quantifying abnormality of placental shape is a meaningful clinical tool. Abnormal shapes are associated with reduced placental efficiency. We hypothesize that such shapes reflect deformations of placental vascular architecture, and that an abnormal placental shape serves as a marker of maternal uteroplacental and/or fetoplacental vascular pathology of sufficiently long standing to impact placental (and by extension, potentially fetal) development. Copyright © 2010 Elsevier Ltd. All rights reserved.

PMID: 2093328

2009

Special Issue - The Intra-uterine Environment and Placentation

July 2009 Volume 215, Issue 1 Pages 1–90

Implantation

2007

The architecture of first trimester chorionic villous vascularization: a confocal laser scanning microscopical study

Hum Reprod. 2007 Aug;22(8):2254-60. Epub 2007 Jun 1.

Lisman BA, van den Hoff MJ, Boer K, Bleker OP, van Groningen K, Exalto N.

Department of Obstetrics and Gynaecology, Academic Medical Centre, University of Amsterdam, PO Box 22700, 1100 DE Amsterdam, The Netherlands. b.a.lisman@amc.uva.nl Abstract BACKGROUND: The aim of this study was to investigate normal chorionic villous vascularization using CD31 immunofluorescence and confocal laser scanning microscopy (CLSM) to elucidate the spatial arrangement in terms of connections between vessels and cords and their branching patterns compared to deficient chorionic villous vascularization in complicated pregnancies.

METHODS: A descriptive morphologic study using CLSM after CD31 immunofluorescence staining of placental biopsies from normal pregnancies (n = 20), complete hydatidiform molar pregnancies (CHMs; n = 3) and empty sacs (n = 3), with a well documented gestational age (GA).

RESULTS: In this three-dimensional study, first trimester chorionic villi were occupied by a complex network of mainly cords with redundant connections as early as 5(+5) weeks GA. With increasing GA cords transform into vessels. From about 9 weeks GA onwards, vascular development is characterized by the presence of two large vessels located centrally and surrounded by and connected to a capillary network. In first trimester CHM and empty sacs, we observed a primitive network of mainly cords.

CONCLUSIONS: This first visualization of the spatio-temporal patterns of blood vessel formation in placental villi is characterized by the development of the vasculosyncytial membrane from a complex network of cords and can be regarded as the placental development before it becomes functional at the end of organogenesis.

PMID 17545656


http://humrep.oxfordjournals.org/content/22/8/2254.long

Timing below - gestational age (LMP)

  • 3- 4 weeks (5 and 6 weeks GA) - a complex network of cords and vessels with redundant connections in chorionic villi is seen. This network comprises mainly cords, already connected together. All vessels and cords are connected to each other without any interruptions. The chorionic villus is completely dominated by a network of vascular elements. Vessels and cords are located centrally as well as peripherally and as a consequence contact the overlying trophoblastic layer (Fig. 1A and B). The luminal diameter of the vessels ranges between 10 and 15 µm (Table 1).


  • 5-6 weeks (7 and 8 weeks GA) - chorionic villi are dominated by a capillary network consisting of vessels and cords. The capillary network contains more vessels than cords. At the tip of the chorionic villus, regular small branched off (mesenchymal) chorionic villi are observed containing a conglomeration of CD31 positive cells (Fig. 2). The luminal diameter of the vessels, ranging between 10 and 26 µm, has increased compared with the earlier stage.
  • 7-8 weeks (9 and 10 weeks GA) - chorionic villi are characterized by the presence of two large vessels located centrally and surrounded by and connected to a capillary network at the periphery of the villus. The capillary network contains mainly vessels with a lumen that are in tight contact with the overlying trophoblastic layer (Fig. 3A and B). From this GA onwards, we observed villous projections containing blindly ending capillary sprouts arising from the underlying capillary network. The luminal diameter of the two centrally located vessels varies between 60 and 75 µm, whereas the vessels of the capillary network range between 26 and 34 µm (Table 1).
  • 9-10 weeks (11 and 12 weeks GA) - immature intermediate villi are characterized by the presence of two large vessels surrounded by a capillary network. Within the network, cords are infrequently present. Blindly ending capillary sprouts branching off the capillary network are present (Fig. 4). The centrally located large vessels range between 70 and 90 µm in diameter and are wider than the vessels between 9 and 10 weeks GA. However, the diameter of the vessels of the capillary network is similar to the previous stage

1998

Examination of the placenta

Am Fam Physician. 1998 Mar 1;57(5):1045-54.

Yetter JF 3rd. Source Department of Family Practice, Madigan Army Medical Center, Fort Lewis, Wash, USA.

Abstract

A one-minute examination of the placenta performed in the delivery room provides information that may be important to the care of both mother and infant. The findings of this assessment should be documented in the delivery records. During the examination, the size, shape, consistency and completeness of the placenta should be determined, and the presence of accessory lobes, placental infarcts, hemorrhage, tumors and nodules should be noted. The umbilical cord should be assessed for length, insertion, number of vessels, thromboses, knots and the presence of Wharton's jelly. The color, luster and odor of the fetal membranes should be evaluated, and the membranes should be examined for the presence of large (velamentous) vessels. Tissue may be retained because of abnormal lobation of the placenta or because of placenta accreta, placenta increta or placenta percreta. Numerous common and uncommon findings of the placenta, umbilical cord and membranes are associated with abnormal fetal development and perinatal morbidity. The placenta should be submitted for pathologic evaluation if an abnormality is detected or certain indications are present. PMID 9518951

1989

Fetal vasculogenesis and angiogenesis in human placental villi

Acta Anat (Basel). 1989;136(3):190-203.

Demir R, Kaufmann P, Castellucci M, Erbengi T, Kotowski A.

Department of Histology and Embryology, Faculty of Medicine, Akdeniz University, Antalya, Turkey. Abstract Placental villi of 5 exactly defined early human specimens ranging from day 21 post conception (p.c.) until day 42 p.c. and from an additional 43 specimens from about 5 to 40 weeks menstrual age have been analyzed ultrastructurally with regard to fetal vasculogenesis and angiogenesis. The following results were obtained: The first cells differentiating at day 21 p.c., probably originating from mesenchymal precursors, are macrophage-like cells. At almost the same time, mesenchymal cells transform into haemangioblastic cell cords which are the forerunners of the capillary endothelium and haematopoietic stem cells. A third cell population related to the fetal circulatory system and derived from the mesenchymal cells are presumptive pericytes. Capillary formation takes place by the aggregation of haemangioblastic cells which are attached to each other by intercellular junctions. The lumen is formed by the dehiscence of the intercellular clefts. A capillary basal lamina cannot be detected earlier than in the last trimester. In this last period of gestation, fetal villous angiogenesis takes place by the proliferation of the existing endothelium and pericytes rather than via haemangioblastic cells.


Vascularization of the placenta takes place around day 21 post conception (p.c.) endothelial progenitor cells appear as cords right beneath the trophoblastic layer. which are called angiogenic cell cords (ACC).

  • These cells proliferate, differentiate and migrate to form main vascular patterns and form primitive vascular tubes (VT), which demonstrate a primitive lumen formation.

PMID 2481376

Placenta Issue

Vol. 54 Nos. 2/3 (2010)

http://www.ijdb.ehu.es/web/contents.php?vol=54&issue=2-3

Anthropometry of fetal vasculature in the chorionic plate

Gordon Z, Elad D, Almog R, Hazan Y, Jaffa AJ, Eytan O. J Anat. 2007 Dec;211(6):698-706. Epub 2007 Oct 30. PMID: 17973911

http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7580.2007.00819.x/full

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2697319/figure/fig1/

A photomicrograph of the human endometrium on the fourth day of menstruation showing an eroded spiral artery (arrowed) projecting freely into the uterine lumen. b) A photomicrograph of spiral arteries in a rhesus monkey during the phase of ovulation injected with India ink in gelatin. The arrow marks the endometrial–myometrial boundary, and a marked constriction (asterisked) can be seen in the spiral artery in the junctional zone just below. c) Reconstruction from serial sections of a converted spiral artery passing through the myometrium (M) and endometrium (E) before opening into the intervillous space through the basal plate of a term placenta. The widest dimension of the opening is given as 2.4 mm. Reproduced from Refs. [83], [15] and [16] respectively with permission of the Carnegie Institute of Washington.

Immunology of placentation in eutherian mammals

http://www.nature.com/nri/journal/v6/n8/full/nri1897.html

The human placenta is a hematopoietic organ during the embryonic and fetal periods of development

http://www.ncbi.nlm.nih.gov/pubmed/19073167

"We studied the potential role of the human placenta as a hematopoietic organ during embryonic and fetal development. Placental samples contained two cell populations-CD34(++)CD45(low) and CD34(+)CD45(low)-that were found in chorionic villi and in the chorioamniotic membrane. CD34(++)CD45(low) cells express many cell surface antigens found on multipotent primitive hematopoietic progenitors and hematopoietic stem cells. CD34(++)CD45(low) cells contained colony-forming units culture (CFU-C) with myeloid and erythroid potential in clonogenic in vitro assays, and they generated CD56(+) natural killer cells and CD19(+)CD20(+)sIgM(+) B cells in polyclonal liquid cultures. CD34(+)CD45(low) cells mostly comprised erythroid- and myeloid-committed progenitors, while CD34(-) cells lacked CFU-C. The placenta-derived precursors were fetal in origin, as demonstrated by FISH using repeat-sequence chromosome-specific probes for X and Y. The number of CD34(++)CD45(low) cells increased with gestational age, but their density (cells per gram of tissue) peaked at 5-8 wk, decreasing more than sevenfold at the onset of the fetal phase (9 wk of gestation). In addition to multipotent progenitors, the placenta contained myeloid- and erythroid-committed progenitors indicative of active in situ hematopoiesis. These data suggest that the human placenta is an important hematopoietic organ, raising the possibility of banking placental hematopoietic stem cells along with cord blood for transplantation."

De novo synthesis of estrogen in pregnant uterus is critical for stromal decidualization and angiogenesis. Das A, Mantena SR, Kannan A, Evans DB, Bagchi MK, Bagchi IC. Proc Natl Acad Sci U S A. 2009 Jul 28;106(30):12542-7. Epub 2009 Jul 20. Erratum in: Proc Natl Acad Sci U S A. 2009 Sep 15;106(37):16003. PMID: 19620711 | PNAS

  • Implantation is initiated when the embryo attaches to the uterine luminal epithelium during early pregnancy.
  • Following this event, uterine stromal cells undergo steroid hormone-dependent transformation into morphologically and functionally distinct decidual cells in a unique process known as decidualization.
  • An angiogenic network is also formed in the uterine stromal bed, critically supporting the early development of the embryo.
  • ovarian progesterone as a key regulator of decidualization is well established
  • these studies in mice - identified the decidual uterus as a novel site of estrogen biosynthesis and uncovered estrogen-regulated maternal signaling pathways that critically control uterine differentiation and angiogenesis during early pregnancy.


Classification of human placental stem villi: review of structural and functional aspects

Microsc Res Tech. 1997 Jul 1-15;38(1-2):29-41.

Demir R, Kosanke G, Kohnen G, Kertschanska S, Kaufmann P.

Department of Histology and Embryology, Medical Faculty, Akdeniz University, Antalya, Turkey. Abstract The stem villi of the human placenta represent the central branches of the villous trees. They are characterized by a condensed fibrous stroma in which the fetal arteries and veins as well as the arterioles and venules are embedded. Functionally they are accepted as the mechanically supporting structures of the villous trees, and they are supposed to control fetal blood flow to the maternofetal exchange area, which is located in the peripheral villi. To obtain further insights into the functions of the stem villi, the recent literature has been reviewed, and some immunohistochemical, ultrastructural, and reconstruction studies have been added. These new studies were aimed at identifying immunohistochemically different subtypes of stem villi, their branching patterns, the distribution of macrophages, the stromal proliferation patterns, and the differentiation of extravascular stromal cells. Our findings demonstrate that the stem villi and their precursors, the immature intermediate villi, can selectively be identified by anti-gamma-smooth muscle (sm) actin staining. Furthermore, the existence of three different subtypes of stem villi is shown; these differ regarding the presence and distribution of gamma-sm actin-positive cells. These cells were immunohistochemically and ultrastructurally identified as smooth muscle cells and myofibroblasts. Increasingly complex coexpression patterns of cytoskeletal proteins reflect a clearly defined differentiation gradient of extravascular stromal cells, which covers the whole range of an undifferentiated germinative layer beneath the trophoblast to highly differentiated myofibroblasts surrounding the medias of the stem vessels. Possible functions of the extravascular contractile system include the regulation of villous turgor and the control of intervillous blood flow impedance.

PMID 9260835

Placenta Measurements

Variable Placenta (n = 15)
Intervillous space, mL 213 (16%)
Stem villi, mL 71.4 (68%)
Peripheral villi, mL 326 (27%)
Trophoblast, mL 95.5 (29%)
Stroma, mL 184 (32%)
Fetal capillaries, mL 46.9 (50%)
Non-parenchyma, mL 41.5 (39%)
Peripheral villi, km 89.2 (23%)
Fetal capillaries, km 310 (37%)
TS area villi, µm2 3700 (21%)
TS area capillary, µm2 150 (27%)
Capillaries, mL mL−1 0.147 (47%)
Length ratio, km km−1 3.6 (38%)

Data http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7580.2008.00994.x/full