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Molecular Medicine Reports Jul 2012The placenta is the organ that is responsible for providing the developing fetus with all the nutrients necessary for its growth and is also responsible for removing... (Review)
Review
The placenta is the organ that is responsible for providing the developing fetus with all the nutrients necessary for its growth and is also responsible for removing fetal waste. Placentation is a crucial process that includes angiogenesis. Angiogenesis involves not only the fetal circulation, but also placental and endometrial vascular changes. In this study, we review the literature regarding any impairment in the angiogenic process in placentas from pregnancies complicated by fetal growth restriction (FGR). Angiogenesis is regulated by a list of factors, also known as growth factors, such as the vascular endothelial growth factor (VEGF), the placental growth factor (PlGF) and the basic fibroblastic growth factor (bFGF), as well as the partial pressure of oxygen in the fetoplacental vessels. Other factors, such as transcriptional factors, also play a pivotal role, controlling the above-mentioned growth factors. Alterations in these pathways have been described in cases of growth-restricted fetuses. In this review, we provide an insight into these processes and identify the most crucial factors involved.
Topics: Angiogenesis Inducing Agents; Female; Fetal Growth Retardation; Humans; Neovascularization, Physiologic; Placenta; Pregnancy
PubMed: 22552373
DOI: 10.3892/mmr.2012.898 -
Placenta Nov 2000The aim of this study was to test whether or not adaptations in partial, total and specific oxygen diffusive conductances occur in the placentae of women who smoke...
The aim of this study was to test whether or not adaptations in partial, total and specific oxygen diffusive conductances occur in the placentae of women who smoke cigarettes during pregnancy and help to compensate for intrauterine fetal hypoxic stress. Tissue sections were randomly sampled from human term placentae divided into two groups (non-smokers and smokers) according to maternal smoking status. In smokers, status was expressed as either declared smoking rate or level of plasma cotinine (the major metabolite of nicotine). Sections were analysed stereologically to estimate key structural quantities (vascular volumes, exchange surface areas, tissue diffusion distances). These were combined with previously-published physicochemical quantities (oxygen-haemoglobin reaction rates and tissue oxygen diffusion coefficients) in order to estimate the partial conductances of six tissue compartments of the oxygen pathway: maternal erythrocytes and plasma, villous trophoblast, villous stroma (including fetal capillary wall), fetal plasma and erythrocytes. From partial conductances and birthweights, total and specific conductances were calculated for each placenta. Results were assessed statistically by analyses of variance and t -tests. Despite apparent improvements in the partial conductances of the maternal erythrocytes and plasma, total and specific conductances did not alter significantly in smoking groups. However, the relative biases affecting these estimates may be different in smokers and non-smokers. We conclude that total conductance does not increase in placentae associated with maternal smoking. However, given that the fetus suffers chronic hypoxic stress as a consequence of smoking (evidenced here by elevated haematocrits), even a constant diffusive conductance implies a reduced transplacental partial pressure gradient. This could be a contributory factor to the reduced birthweight.
Topics: Adult; Birth Weight; Chemical Phenomena; Chemistry, Physical; Cotinine; Diffusion; Female; Humans; Infant, Newborn; Organ Size; Oxygen; Placenta; Pregnancy; Smoking
PubMed: 11095932
DOI: 10.1053/plac.2000.0571 -
Lakartidningen Jan 1980
Topics: Female; Humans; Infant, Low Birth Weight; Infant, Newborn; Organ Size; Placenta; Placenta Diseases; Pregnancy
PubMed: 7366292
DOI: No ID Found -
Archives of Pathology & Laboratory... Jul 2006It has long been recognized that routine histologic examination of the placenta has limitations, especially with regard to the diagnosis of infectious diseases and the... (Review)
Review
It has long been recognized that routine histologic examination of the placenta has limitations, especially with regard to the diagnosis of infectious diseases and the concomitant cytokine response that may cause severe in utero fetal damage. Immunohistochemical testing of the placenta in such situations can be very useful in terms of identifying the infectious agent as well as in demonstrating a marked increase in cytokines such as tumor necrosis factor alpha and interleukin 8, produced primarily by cells native to the villi and fetal membranes. One hundred placentas (20 normal childbirths, 20 with severe neonatal morbidity of known cause, 25 idiopathic stillbirths where autopsy material was available, 35 with severe idiopathic neonatal morbidity) were examined for a wide variety of infectious diseases and cytokine production. An infectious agent was evident in 19 (76%) of 25 placentas from stillbirths and 28 (80%) of 35 placentas associated with idiopathic severe neonatal morbidity. No infectious agent was noted in the placentas from normal childbirths or cases of known neonatal morbidity. The most common infectious agent was coxsackie virus (51% of infections) followed by bacterial infections (24% of infections). The same infectious agent found in the placenta was found in the corresponding autopsy material from the stillbirths, with the spleen containing the greatest number of infected cells. There was a strong correlation between the number of cells demonstrating cytokine expression (tumor necrosis factor alpha and interleukin 8) and the presence of an infectious disease in the placenta and stillborn. No histologic feature was associated with an in utero infection. Immunohistochemical testing of placentas gives much insight into their structure and function, including, besides infectious disease detection, the marked diversity of function of trophoblasts, the rarity of committed B cell response, and the strong potential of contractility of villi.
Topics: Adult; Biomarkers; Cytokines; Female; Humans; Immunohistochemistry; In Situ Hybridization; Infant, Newborn; Infant, Newborn, Diseases; Placenta; Placenta Diseases; Pregnancy
PubMed: 16831054
DOI: 10.5858/2006-130-979-TUOIAI -
Placenta 1983The placentae of 11 chimpanzees and five orang-utans were collected from Japanese zoos immediately after delivery and were examined according to the methods routinely...
The placentae of 11 chimpanzees and five orang-utans were collected from Japanese zoos immediately after delivery and were examined according to the methods routinely used for the human placenta. Placenta extrachorialis (circumvallate and circummarginate placenta) occurred in 80 per cent of the specimens collected from each species. In both groups, the placental vessels were distributed predominantly in the magistral pattern, and the umbilical cord was eccentrically inserted. Subchorionic fibrin, sometimes marked, was seen in all 16 placentae, and there was a high incidence of small intervillous thrombi and deposits of intervillous fibrin. These observations, together with the histological and ultrastructural findings, confirm the previously reported similarity between the placentae of the great apes and the human placentae.
Topics: Animals; Female; Hominidae; Pan troglodytes; Placenta; Pongo pygmaeus; Pregnancy; Pregnancy, Animal
PubMed: 6622432
DOI: 10.1016/s0143-4004(83)80007-1 -
Journal of Reproduction and Fertility Oct 1975Placental attachment and the ultrastructure of the decidua and placental labyrinth have been studied in rabbits during the final third of gestation. The placenta became...
Placental attachment and the ultrastructure of the decidua and placental labyrinth have been studied in rabbits during the final third of gestation. The placenta became progressively easier to separate from the uterine wall as gestation proceeded. This ease of separation was associated with degenerative changes in the decidual tissue, but disruption of the placental labyrinth was not observed until the last 24 hr of pregnancy. Two types of decidual cells were observed; smaller uninucleate glycogen-containing cells and larger multinucleate cells with lipid inclusions. The ageing placentae exhibited increasing decidual degeneration associated with deposition of extracellular fibrous materials. Glycogen became less widely distributed over the period of study and changed from the beta- to the alpha-configuration. In contrast to the observed disruption of the decidual tissue, the placental labyrinth maintained its integrity until the final stages of pregnancy. A dramatic increase in subcellular activity was observed in the syncytiotrophoblast after 28 days of gestation.
Topics: Animals; Decidua; Female; Glycogen; Placenta; Pregnancy; Pregnancy, Animal; Rabbits; Trophoblasts
PubMed: 1238566
DOI: 10.1530/jrf.0.0450009 -
Journal of Ayub Medical College,... 2005Gestational diabetes is much more common than pre-existing diabetes i.e. it complicates 2% to 5% of pregnancies. When metabolic control is good, perinatal mortality...
BACKGROUND
Gestational diabetes is much more common than pre-existing diabetes i.e. it complicates 2% to 5% of pregnancies. When metabolic control is good, perinatal mortality should be no higher than in general population. However, macrosomia continuous to be a problem in higher than average proportions of such cases. Macrosomia also involves placenta within the chronic hypertensive disease, the most common diagnosis is essential vascular hypertension.
METHODS
Total 60 full term placenta, 20 from normal and 20 each from gestational diabetics and chronic hypertensive mothers were studied grossly. Shape, attachment of umbilical cord, weight, diameter and central thickness of all placentas were noted.
RESULTS
The study demonstrates that there is change of shape i.e. two lobes in one placenta from diabetic group. All other placentae were singly lobed and discoidal shape with central attachment of umbilical cord to the foetal surface of placenta. Weight central thickness and diameter were significantly greater in diabetic group as compared to normal and hypertensive group. Hypertensive group shows non significant decrease in weight of placentae while there was no change in central thickness and diameter of placenta in hypertensive than the normal group.
CONCLUSIONS
On the basis of results of present study, it is concluded that diabetic's placentae showed increase in weight, central thickness and diameter. One out of 20 placentae in diabetic group also showed change of shape and attachment of umbilical cord to one love. Hypertensive's placentae showed no significant change in weight, shape central thickness and attachment of umbilical cord when compared with normal group.
Topics: Adult; Diabetes, Gestational; Female; Humans; Hypertension; Placenta; Pregnancy; Pregnancy Complications, Cardiovascular
PubMed: 15929527
DOI: No ID Found -
Placenta Sep 2020We aim to examine the location of the vascular equator according to the umbilical cord insertions in monochorionic twin placentas.
INTRODUCTION
We aim to examine the location of the vascular equator according to the umbilical cord insertions in monochorionic twin placentas.
METHODS
We combined two prospective series of monochorionic diamniotic twin placentas of patients included in the first trimester between 2004 and 2008, and between 2016 and 2019. We injected the placentas after birth and divided them into three groups, with respectively concordant (eccentric-eccentric, marginal-marginal, and velamentous-velamentous), intermediate (eccentric-marginal and marginal-velamentous) and discordant (eccentric-velamentous) cord insertions. For each unidirectional anastomosis, we determined the cord-anastomosis ratio and then calculated the mean ratio per placenta in each group. We also calculated the deviation from the midline in all groups.
RESULTS
195 placentas were included. In concordant placentas, the mean cord-anastomosis ratio was 0.957 (95% CI [0.908-1.009]). In placentas with intermediate discordance, the mean ratio was 0.886 (95% CI [0.828-0.948]) and in discordant placentas it was 0.797 (95% CI [0,708-0.897]) (p < 0.001). In concordant placentas, the equator was in the middle of the cord insertions with an average deviation of 0.2 cm (95% CI [-0.1 - 0.3]). In the intermediate placentas, the equator deviated on average 0.5 cm (95% CI [0.2-0.8]) and was displaced from the middle towards the most central cord insertion. In discordant placentas, there was an average displacement of 1.0 cm (95% CI [0.50-1.6]).
DISCUSSION
In concordant placentas, the vascular equator lies in the middle between both cord insertions. In intermediate and discordant placentas, the equator is closer to the more central cord insertion.
Topics: Adult; Female; Fetofetal Transfusion; Humans; Laser Therapy; Placenta; Pregnancy; Twins, Monozygotic; Ultrasonography, Prenatal; Umbilical Cord
PubMed: 32988575
DOI: 10.1016/j.placenta.2020.05.008 -
Hypertension in Pregnancy 2010To compare histopathological differences in placentas from early- and late-onset preeclampsia, as well as late-onset preeclampsia and normal term deliveries.
OBJECTIVE
To compare histopathological differences in placentas from early- and late-onset preeclampsia, as well as late-onset preeclampsia and normal term deliveries.
METHODS
This prospective study was performed at Tygerberg Hospital, a secondary and tertiary referral center in South Africa. Placentas from 100 women, 25 each with early and late-onset preeclampsia, and an equal number of controls matched for gestational age, underwent routine preparation and were evaluated independently by two pathologists in a strictly predetermined, standardized manner.
RESULTS
Compared to late preeclampsia, placentas in the early preeclampsia group were smaller (p < 0.01), had more infarction (odds ratio [OR] = 4.03, 95% confidence interval [CI] = 1.2-13.5) and inappropriate maturation (OR = 16.62, 95% CI = 4.1-68.0). Placentas from the late-onset preeclampsia group showed increased decidual arteriopathy (OR = 5.09, 95% CI = 1.45-17.92) and abruptio placentae (OR = 5.41, 95% CI = 1.01-28.79) compared to controls.
CONCLUSIONS
The early- and late-onset preeclampsia placentas showed clear histopathological differences, whereas late-onset preeclampsia and normal term placentas differed less. These findings support the contention that early- and late-onset preeclampsia are different subclasses of disease.
Topics: Adult; Case-Control Studies; Female; Gestational Age; Humans; Odds Ratio; Placenta; Pre-Eclampsia; Pregnancy
PubMed: 20701467
DOI: 10.3109/10641950903572282 -
Molecular Imaging and Biology Jun 2011The purpose of this study was to develop a tool for functional phenotyping of the maternal circulation in the mouse placenta.
PURPOSE
The purpose of this study was to develop a tool for functional phenotyping of the maternal circulation in the mouse placenta.
PROCEDURES
In utero macromolecular dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed on embryonic day 10.5 (E10.5), E13.5, and E18.5. Fluorescence analysis was also used for validation of the results.
RESULTS
The initial rate of contrast enhancement revealed an increased maternal blood volume fraction as the pregnancy progressed. Serial imaging of E10.5 and E13.5 placentas revealed a loss of contrast enhancement due to phagocytic uptake. A key application of macromolecular DCE-MRI would be to follow mouse pregnancies during fetal and placental manipulation including embryo transfer, tetraploid complementation, and fetal resorptions. We were able to resolve strain differences in ICR outbred mice carrying both ICR and C57Bl/6J embryos and to differentiate in utero resorptions from functional placentas.
CONCLUSIONS
Our results highlight the importance of the functional in utero analysis of placental vascularization in physiological phenotyping of transgenic mice and suggest MRI, particularly macromolecular DCE-MRI, as a non-invasive tool for the analysis of the placenta.
Topics: Albumins; Animals; Blood Circulation; Contrast Media; Embryo, Mammalian; Female; Magnetic Resonance Imaging; Mice; Organ Size; Phenotype; Placenta; Polyploidy; Pregnancy; Species Specificity; Time Factors
PubMed: 20686857
DOI: 10.1007/s11307-010-0390-1