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Placenta 1986We have studied regional anatomical variability in four term placentae, comparing both whole placental regions and intralobar zones and plates. In addition, we have...
We have studied regional anatomical variability in four term placentae, comparing both whole placental regions and intralobar zones and plates. In addition, we have emphasized the need for careful selection of the area to be sampled, rather than strictly randomized sampling of the whole placenta. A unique contribution is our quantitative data for a number of structures of the several intralobar zones and plates. The data confirm the hypothesis that the area best suited to physiological exchange is the central region parabasal plate. The relative homogeneity of the intralobar zones in this area make it a representative area for sampling for various placental studies.
Topics: Capillaries; Chorionic Villi; Female; Humans; Necrosis; Placenta; Pregnancy; Pregnancy Trimester, Third
PubMed: 3737577
DOI: 10.1016/s0143-4004(86)80161-8 -
European Journal of Obstetrics,... Nov 1995The anatomic structure of the placenta varies widely at the macroscopic and microscopic levels, and these differences are often reflected in differences in exchange... (Comparative Study)
Comparative Study Review
The anatomic structure of the placenta varies widely at the macroscopic and microscopic levels, and these differences are often reflected in differences in exchange mechanisms. For example, placental iron transfer proceeds by three distinct mechanisms each associated with a distinctive anatomic feature. A number of factors also affect the exchange capacity per unit of placental tissue, these include boundary properties and the arrangement and rates of fetal and maternal placental blood flows. Generally, the exchange rate of a substrate is limited principally by the membranes or by blood flow but these interact in a complex fashion. When exchange occurs by relatively slow passive diffusion, the barrier thickness and exchange area per gram of placenta are most important. The T-diagram reveals that a counter- or crosscurrent arrangement of blood streams is most efficient. However, relatively few placentas make use of these high efficiency designs. It is suggested that only in animals such as rodents and shrews where a large fetus is produced in a short time by a small placenta does placental exchange capacity need to be pushed to its theoretical limits. We define an index termed the 'turbo factor' (= term fetal weight/[placental weight x days of gestation]) to express the extent to which growth taxes the placenta. A value of > 0.2 seems to require a placenta of the high-efficiency type and may predict that, in a given species, the placenta makes use of the most efficient arrangement of blood flows.
Topics: Animals; Capillary Permeability; Diffusion; Female; Humans; Maternal-Fetal Exchange; Placenta; Pregnancy; Sheep; Species Specificity
PubMed: 8674572
DOI: 10.1016/0301-2115(95)02206-m -
American Journal of Clinical Pathology Jun 2020To describe histopathologic findings in the placentas of women with coronavirus disease 2019 (COVID-19) during pregnancy.
OBJECTIVES
To describe histopathologic findings in the placentas of women with coronavirus disease 2019 (COVID-19) during pregnancy.
METHODS
Pregnant women with COVID-19 delivering between March 18, 2020, and May 5, 2020, were identified. Placentas were examined and compared to historical controls and women with placental evaluation for a history of melanoma.
RESULTS
Sixteen placentas from patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were examined (15 with live birth in the third trimester, 1 delivered in the second trimester after intrauterine fetal demise). Compared to controls, third trimester placentas were significantly more likely to show at least one feature of maternal vascular malperfusion (MVM), particularly abnormal or injured maternal vessels, and intervillous thrombi. Rates of acute and chronic inflammation were not increased.The placenta from the patient with intrauterine fetal demise showed villous edema and a retroplacental hematoma.
CONCLUSIONS
Relative to controls, COVID-19 placentas show increased prevalence of decidual arteriopathy and other features of MVM, a pattern of placental injury reflecting abnormalities in oxygenation within the intervillous space associated with adverse perinatal outcomes. Only 1 COVID-19 patient was hypertensive despite the association of MVM with hypertensive disorders and preeclampsia. These changes may reflect a systemic inflammatory or hypercoagulable state influencing placental physiology.
Topics: Adult; Betacoronavirus; COVID-19; Case-Control Studies; Coronavirus Infections; Female; Humans; Pandemics; Placenta; Pneumonia, Viral; Pregnancy; Pregnancy Complications, Infectious; Pregnancy Trimester, Third; SARS-CoV-2
PubMed: 32441303
DOI: 10.1093/ajcp/aqaa089 -
Pediatric Research Nov 2005The placenta is essential to nutrition before birth. Recent work has shown that a range of clearly defined alterations can be found in the placentas of infants with... (Review)
Review
The placenta is essential to nutrition before birth. Recent work has shown that a range of clearly defined alterations can be found in the placentas of infants with intrauterine growth restriction (IUGR). In the mouse, a placental specific knockout of a single imprinted gene, encoding IGF-2, results in one pattern of alterations in placenta structure and function which leads to IUGR. We speculate that the alterations in the human placenta can also be grouped into patterns, or phenotypes, that are associated with specific patterns of fetal growth. Identifying the placental phenotypes of different fetal growth patterns will improve the ability of clinicians to recognize high-risk patients, of laboratory scientists to disentangle the complexities of IUGR, and of public health teams to target interventions aimed at ameliorating the long-term adverse effects of inadequate intrauterine growth.
Topics: Animals; Female; Fetal Development; Fetal Growth Retardation; Humans; Maternal-Fetal Exchange; Mice; Phenotype; Placenta; Pregnancy
PubMed: 16183820
DOI: 10.1203/01.PDR.0000181381.82856.23 -
Biotechnic & Histochemistry : Official... 2017Cadmium (Cd) is an industrial and environmental pollutant that produces toxic effects on gametogenesis, pre- and post-implantation embryos, and the placenta. Because the...
Cadmium (Cd) is an industrial and environmental pollutant that produces toxic effects on gametogenesis, pre- and post-implantation embryos, and the placenta. Because the effects of acute Cd intoxication on the placenta are not well understood, we investigated changes in its glycosylated components in Cd treated dams at days 4, 7, 10 and 15 of gestation using lectin histochemistry. CdCl was administered to pregnant rats; control animals received sterile normal saline. Placentas were processed for DBA, Con A, SBA, PNA, UEA-I, RCA-I and WGA lectin histochemistry to evaluate changes in the carbohydrate pattern of the placenta that might modify cell interactions and contribute to embryonic alterations. Lectin binding was analyzed in the yolk sac; trophoblast giant cells; trophoblast I, II and III; spongiotrophoblast cells and endovascular trophoblast cells in the chorioallantoic placenta. Our lectin binding patterns showed that Cd caused alteration of SBA and DBA labeling of trophoblast-derived cells, which suggested increased expressions of α and β GalNAc. Cd also caused decreased UEA-1 binding affinity, which indicated fewer α-L-Fuc residues in placentas of Cd treated dams. The nonreactivity in trophoblast I of the control placentas incubated with Con-A contrasted with the labeling in placentas of experimental dams, which indicated increased expression of terminal α-D-Man, and α-D-Glc residues. We found that Cd altered the reactivity of placenta to several lectins, which indicated modification of the glycotype presented by the fetal component of the placenta. We report that Cd exerts a deleterious effect on the glycosylation pattern of the placenta.
Topics: Animals; Cadmium; Female; Glycosylation; Lectins; Placenta; Pregnancy; Rats; Rats, Wistar; Trophoblasts
PubMed: 28166424
DOI: 10.1080/10520295.2016.1185668 -
American Journal of Obstetrics and... Jun 2011We sought to determine whether CD11b(+)Gr1(+) immature myeloid cells (IMCs), which have been shown to promote tumor angiogenesis, accumulate in the placenta and...
OBJECTIVE
We sought to determine whether CD11b(+)Gr1(+) immature myeloid cells (IMCs), which have been shown to promote tumor angiogenesis, accumulate in the placenta and similarly contribute to blood vessel formation.
STUDY DESIGN
Experiments were performed on 6- to 8-week-old C57Bl/6J female mice. Placentas from pregnant mice or B16F10 tumors that were subcutaneously implanted were analyzed by flow cytometry and confocal microscopy. To determine the proangiogenic potential of IMCs, Matrigel plug assays were performed.
RESULTS
IMCs infiltrate the placenta in the proximity of blood vessels, reaching peak concentration at midpregnancy. When isolated from either placentas or B16F10 melanoma tumors, IMCs actively promoted endothelial cell migration into Matrigel plugs in vivo. Furthermore, placental IMCs, similar to tumor-derived IMCs, expressed matrix metalloproteinase-9 and Bv8, 2 pivotal proangiogenic proteins.
CONCLUSION
IMCs that express matrix metalloproteinase-9 and Bv8 infiltrate placentas of pregnant mice and actively promote angiogenesis. These cells show striking similarity to IMCs that populate malignant tumors.
Topics: Animals; Female; Mice; Mice, Inbred C57BL; Myeloid Cells; Neovascularization, Physiologic; Placenta; Pregnancy
PubMed: 21420066
DOI: 10.1016/j.ajog.2011.01.060 -
Molecular and Cellular Endocrinology Jan 2016The placenta is important for the success of gestation and foetal development. In fact, this specialized pregnancy organ is essential for foetal nourishment, support,... (Review)
Review
The placenta is important for the success of gestation and foetal development. In fact, this specialized pregnancy organ is essential for foetal nourishment, support, and protection. In the placenta, there are different cell populations, including four subtypes of trophoblasts. Cytotrophoblasts fuse and differentiate into the multinucleated syncytiotrophoblast (syncytialization). Syncytialization is a hallmark of placentation and is highly regulated by numerous molecules with distinct roles. Placentas from pregnancies complicated by preeclampsia, intrauterine growth restriction or trisomy 21 have been associated with a defective syncytialization and an altered expression of its modulators. This work proposes to review the molecules that promote or inhibit both fusion and biochemical differentiation of cytotrophoblasts. Moreover, it will also analyse the syncytialization modulators abnormally expressed in pathological placentas, highlighting the molecules that may contribute to the aetiology of these diseases.
Topics: Animals; Female; Giant Cells; Humans; Placenta; Pregnancy
PubMed: 26586208
DOI: 10.1016/j.mce.2015.11.010 -
Best Practice & Research. Clinical... Jun 2011Defective deep placentation is characterised by defective remodelling of the utero-placental arteries. Under certain conditions, it is also characterised by the presence... (Review)
Review
Defective deep placentation is characterised by defective remodelling of the utero-placental arteries. Under certain conditions, it is also characterised by the presence of arterial lesions, such as acute atherosis and the persistence of endovascular trophoblast. The condition has been associated with a spectrum of complications during pregnancy, including pre-eclampsia, intrauterine growth restriction, pre-term birth, pre-term premature rupture of membranes, late sporadic miscarriage and abruptio placentae. Criteria are proposed for the classification of defective deep placentation into three types based on the degree of restriction of remodelling and the presence of obstructive lesions in the myometrial segment of the spiral arteries. Although the underlying mechanisms are not understood, evidence is emerging that the origin of defective deep placentation may not lie in primary defect of the trophoblast, but in abnormalities of the endometrium and inner myometrium before or during the early stages of placentation.
Topics: Female; Humans; Placenta; Placenta Diseases; Placentation; Pregnancy
PubMed: 21109492
DOI: 10.1016/j.bpobgyn.2010.10.012 -
Journal of Visualized Experiments : JoVE Apr 2023The placenta is an essential organ that regulates and maintains mammalian development in utero. The placenta is responsible for the transfer of nutrients and waste...
The placenta is an essential organ that regulates and maintains mammalian development in utero. The placenta is responsible for the transfer of nutrients and waste between the mother and fetus and the production and delivery of growth factors and hormones. Placental genetic manipulations in mice are critical for understanding the placenta's specific role in prenatal development. Placental-specific Cre-expressing transgenic mice have varying effectiveness, and other methods for placental gene manipulation can be useful alternatives. This paper describes a technique to directly alter placental gene expression using CRISPR gene manipulation, which can be used to modify the expression of targeted genes. Using a relatively advanced surgical approach, pregnant dams undergo a laparotomy on embryonic day 12.5 (E12.5), and a CRISPR plasmid is delivered by a glass micropipette into the individual placentas. The plasmid is immediately electroporated after each injection. After dam recovery, the placentas and embryos can continue development until assessment at a later time point. The evaluation of the placenta and offspring after the use of this technique can determine the role of time-specific placental function in development. This type of manipulation will allow for a better understanding of how placental genetics and function impact fetal growth and development in multiple disease contexts.
Topics: Pregnancy; Female; Mice; Animals; Placenta; Clustered Regularly Interspaced Short Palindromic Repeats; Fetal Development; Fetus; Mammals
PubMed: 37125793
DOI: 10.3791/64760 -
Nigerian Journal of Medicine : Journal... 2014Pre-term delivery is usually associated with low birth weight and is a known obstectrics problem in our setting. Few Histopathologists are interested in placental...
BACKGROUND
Pre-term delivery is usually associated with low birth weight and is a known obstectrics problem in our setting. Few Histopathologists are interested in placental pathology, and this is particularly so because consent is often difficult to get from the relatives making few specimens available for study in our environment.
OBJECTIVE
Our objective was to evaluate the placental histopathology in low birth weight infants (LBW, birth weight < 2500 g) and to determine if placental histopathological findings are associated with low birth weight and preterm deliveries.
METHODS
The placenta of thirty-eight consecutive cases of LBW deliveries at the Obafemi Awolowo University Teaching Hospital, Wesley Guild Hospital, (lesa were histologically examined.
RESULTS
A total of thirty-eight LBW placentas were examined. The Male: Female ratio was 1.8:1. The maternal age range 19 - 38 years (mean age = 28.7 yrs +/- 5.37SD). The parity ranged from 0 to 5. The birth weight ranged 0.75 - 2.4kg (mean 1.84kg +/- 0.39SD). The gestational age at delivery range was 25 - 38 weeks (mean 32.85 weeks +/- 3.7SD). Histological examination of the placentae showed that 17 cases (44.7%) had evidence of placenta malaria (PM), 17 cases (44.7%) had chorioamnionitis (CA), 9 cases (23.7%) had villitis, 2 cases (5.3%) had vasculitis and 4 cases (10.5%) had no abnormality. Four sets of twins (8 cases) were among the 38 cases seen. A case of abruptio placenta was delivered by caesarean section, with histological diagnosis of active- chronic malaria. Out of the cases with CA11 (64.7%) had mild CA, 4 (23.6%) moderate while 2 (11.8) had severe infection. Placenta malaria co-infection was also found in 7 (41%) of the CA. Nine (23:7%) had villitis, only 2 cases had umbilical cord vasculitis. Of the cases with PM, 10 (58.8) had active-chronic infection while 7 (41.2%) had evidence of past infection.
CONCLUSION
The main placenta findings histologically in LBW babies include chorioamnionitis and placenta malaria infection. These are known contributory factors to preterm labour. Improved maternity care, health education of pregnant women to reduce ascending infection and use of intermittent preventive treatment for malaria in pregnancy will go a long way in improving outcome of pregnancy.
Topics: Adult; Birth Weight; Chorioamnionitis; Female; Gestational Age; Humans; Infant, Low Birth Weight; Infant, Newborn; Infant, Premature; Malaria; Male; Maternal Age; Nigeria; Parity; Placenta; Pregnancy; Young Adult
PubMed: 24956688
DOI: No ID Found