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PubMed2003

Transabdominal sonography before uterine exploration as a predictor of retained placental fragments.

OBJECTIVE: To evaluate the diagnostic accuracy of sonography in postpartum patients thought to have retained placental fragments. METHODS: The study group consisted of 39 postpartum women in whom inspection of the placenta brought up suspicion of retained placental fragments. All these women underwent manual exploration of the uterine cavity. Before the procedure, all patients had two-dimensional sonographic imaging, after which they were divided into 2 groups. The first group comprised women who were judged to have had an empty uterus or nothing but intrauterine fluid collection. The second group consisted of those in whom sonography showed echoes of what might appear as residual trophoblastic tissue, that is, echogenic, hypoechoic, or mixed echo intracavitary patterns. The sonographic patterns were then correlated with the presence or absence of retained placental fragments as found on uterine manual exploration and pathologic examination. RESULTS: In 18 patients, no suspected contents were observed on sonography. In 17 of these patients, the uterus was empty on manual uterine exploration. One of these patients had residual trophoblastic tissue, which was of minimal quantity and clinically unimportant. In 21 patients, sonography suggested retained placental tissue. In 15 of these patients, pathologic examination confirmed residual trophoblastic tissue, and in the remaining 6, the uterus contained blood clots, decidua, or both. CONCLUSIONS: Sonography is an effective tool for evaluating postpartum patients thought to have retained placental fragments. Normal sonographic findings might obviate the need for manual exploration of the uterine cavity. A questionable sonographic result is not an effective tool for distinguishing between placental fragments and blood clots.

Abdomen↗

PubMed1979

The fine structure of placental junctional zone cells during prolonged pregnancy in rats.

The electron microscope was used to examine the junctional zone of the chorioallantoic placentas of living rat young which had been experimentally retained in utero for as long as 4 days beyond delivery of their littermates. Junctional zone cells in such prolonged placentas were compared with corresponding cellular elements in term placentas. By the 1st day of the postterm period, placental glycogen cells in the junctional zone were depleted. Many trophoblast giant cells and trophospongial elements appeared fully viable throughout the entire 4-day period, however, Giant cells from placentas of prolonged pregnancy were indistinguishable from those in placentas at term. Both in term and in postterm placentas the trophospongial elements displayed a variation in the organization of the granular cisterns of endoplasmic reticulum within them. No variants appearing to prefigure involution were identified either in term or in prolonged placentas. However, more cells with vesiculate cisterns were seen in junctional zones from placentas which were retained beyond term. Intercellular relationships also were preserved both in term and in prolonged placentas, it is concluded that parturition is not dependent on their involution.

Animals↗

PubMed2002

Color Doppler and gray-scale ultrasound evaluation of the postpartum uterus.

OBJECTIVES: To evaluate the color Doppler and gray-scale sonographic appearance of the uterus after pregnancy, with special attention to the occurrence of areas of enhanced vascularity and placental remnants. PATIENTS AND METHODS: Cross-sectional observational study involving 385 consecutive women presenting at their first visit after pregnancy. The uterus was evaluated using ultrasound with color Doppler. In the presence of placental remnants, blood was sampled for measurement of beta human chorionic gonadotropin (beta hCG), hemoglobin (Hb) and infectious parameters. If indicated, a dilatation and curettage was performed. RESULTS: In 8.3% of women, areas of enhanced vascularity were detected with color Doppler examination. Most cases (68.9%) were focal areas of one or more vessels. In 2.6% of patients abnormal vascularity extended over a large area of the whole myometrium. In 6.75% of cases, placental remnants were detected. In 46% of these, blood sampling revealed beta hCG levels below 30 mIU/mL; serological infection parameters and Hb concentration were within the normal range. CONCLUSIONS: Areas of enhanced vascularity of the uterus, ranging from a focal vascular pedicle to a larger area of the myometrium, are relatively common after pregnancy. They are predominantly seen in the presence of placental remnants, in the early postpartum period and after instrumental or manual delivery of the placenta. There are no clear risk factors for retained placental tissue, besides the history of blood transfusion in the early postpartum, and perhaps multigravidity. Serology is of little help in the diagnosis of retained gestational products. The knowledge of the ultrasound and color Doppler features of the uterus after pregnancy may prove of practical value for the management of abnormal uterine bleeding in the postpartum period.

Adolescent↗

PubMed2005

The molecular changes during placental detachment.

OBJECTIVES: RCAS1 is a membrane protein that plays a role in the maintenance of maternal immune tolerance during pregnancy. The work presented here demonstrates the results of RCAS1 expression in placenta in cases of placental abruption and patients with retained placental tissue during the third stage of labor. STUDY DESIGN: The placenta tissue samples were obtained during vaginal and cesarean delivery (derived from 117 pregnancies). Pregnant women were divided into four groups according to the onset of labor and the time of placental detachment in term labors. The samples were analyzed by the Western blot method. Statistical analysis was performed using the Shapiro-Wilk procedure. The Mann-Whitney test and Student's t-test were applied to compare the differences between parametric data. RESULTS: The average relative amount of RCAS1 observed in those patients with retained placental tissue was statistically significantly higher than in the patients with placental abruption. CONCLUSION: The differences observed in placental RCAS1 levels confirm the participation of this protein in the inhibition of maternal immune response during gestation. The present results also indicate that RCAS1 participates in the changes in the maternal immune system that take place during parturition and reinforce its potential involvement in the mechanism of placental abruption.

Abruptio Placentae↗

PubMed1987

New aspects of infantile oxalosis.

Infantile oxalosis is the most severe form of primary hyperoxaluria type I (PH I). Only 28 patients have been reported in detail; it was found that diagnosis was usually delayed, and most patients presented before the age of 4 months in renal failure and died within the 1st year of life. This report comprises two infants in whom diagnosis of PH I was made in the first few weeks of life before renal function was impaired. Case 1, whose brother had died of infantile oxalosis, already had greatly increased urinary oxalate and glycolate excretion at 7 days of age. In Case 2, PH I was diagnosed early because of the finding of increased renal echogenicity at 3 weeks of age; this patient had numerous episodes of stone formation despite continuous treatment with pyridoxine, but maintained renal function with normal serum creatinine levels at the age of 28 months. Prenatal diagnosis was attempted in case 1; however, amniotic fluid oxalate and glycolate concentrations were normal, suggesting that these acids pass the placenta and are not retained. The recent discovery of a transamination defect (deficiency of the peroxisomal enzyme alanine: glyoxylate aminotransferase) explains why some patients respond to pyridoxine treatment. Differences in onset and severity of PH I and in response to pyridoxine suggest that this disorder is biochemically and genetically heterogeneous.

Adolescent↗

PubMed1998

Intolerance to volume expansion: a theorized mechanism for the development of preeclampsia.

We present a theorized mechanism for the development of preeclampsia, suggesting that one important underlying pathophysiologic mechanism is intolerance to volume expansion. The stage is set for this intolerance by chronic volume constriction, which leads to a requirement for increased basal peripheral vasoconstrictor tone to maintain blood pressure and allow for continued perfusion of the upright hominid head. In pregnancy, volume expansion signaled by the placenta cannot be accommodated by the constricted vascular system. The inability of the normally adaptive endothelial vasodilatory mechanisms to overcome the chronic vasoconstrictor tone leads to endothelial damage, exacerbation of vasoconstriction, and clinical hypertension. Disease resolution, characterized by diuresis, occurs with the elimination of the placenta-derived drive to retain volume. The reason preeclampsia does not recur uniformly with subsequent pregnancy is permanent restructuring of the maternal cardiovascular system with pregnancy that allows for greater plasma volume expansion in future gestations.

Female↗

PubMed2002

The road ended up at stem cells.

For me the search for hematopoietic stem cells (HSC) actually started with the discovery by Till, McCulloch, and colleagues (1-3) that bone marrow contained single cells that could give rise to myeloerythroid colonies in the spleen, and sometimes these colonies contained cells that made more spleen colonies as well as radioprotected and reconstituted lethally irradiated mice (3). But in retrospect, it should have started with the remarkable observation of Ray Owen in 1945 that bovine fraternal twins sharing a single placenta and blood circulation retained production of blood cells genetically defined to be from both throughout their life (4). It could be argued that this was the experiment that began both modern experimental hematology as well as modern cellular immunology. The Till, McCulloch, Wu, Becker, and Simonovitch experiments were elegant demonstrations that single, genetically marked cells existed (random DNA breaks and translocations induced by sublethal irradiation of the donor bone marrow) that could both self-renew and differentiate (2, 5). But these experiments did not put the pure cells in the hands of scientists, and so most of their functions for the next 25 years were implied rather than directly analyzed. Just as genetics is the complement to biochemistry (when one considers genes and gene products), cell marking is the complement to cell purification in the fields of developmental and cellular biology. The first attempts at such cellular purification came from the 'school' of Till & McCulloch (6, 7), and independently the school of Van Bekkum in the Netherlands (8). But what was lacking in those experiments and at that time were both a comprehensive approach that would take into account the clonal activity of stem cells in both self-renewal and differentiation to all blood cell outcomes, and the tools with which one could separate what turned out to be an extremely rare population in the bone marrow. And, it wasn't known until much later that most day 8-10 spleen colonies were the progeny of progenitors, not stem cells (9). Two inventions facilitated the technology of purification of HSC: the advent of monoclonal antibody technology by Kohler & Milstein (10), and the development of the multiparameter fluorescence activated cell sorter by the Herzenberg group (11). My laboratory had established assays for the clonal precursors of T cells and B cells, and we had been using the Till-McCulloch spleen colony clonal assays since the mid-1960s. In the late 1970s and early 1980s we began in earnest the search for mouse early hematopoietic progenitors, including HSCs (12-16). The purification of HSCs proved to be much like the purification of an enzyme, or a cell surface receptor, or a gene. Successive enrichments finally led to the isolation of a population, which could no longer be subdivided and which contained precursors that read out in all clonal assays as well as in radioprotection of lethally irradiated hosts (17). Our first experiments transplanting single HSC in 1991 and 1992, led to the definitive demonstration that these were indeed HSCs (18-20). But these experiments and the ideas that led to them were developed in the context of immunology and experimental hematology as they were emerging in the 1950s and 60 s. This volume of Immunological Reviews is a rich testimony to the kinds of ideas and experiments that, at least in retrospect, turned out to be critical. Many roads were taken, but only one ended up at stem cells.

Allergy and Immunology↗

PubMed1996

[Effect of the beta receptor blockader carazolol on the dropping and retention of the placenta in the camel (C. dromedarius)].

The current study was conducted to estimate the time needed for placental dropping and the effect of beta-blocker carazolol (Suacron, Praemix, Mannheim) on placental retention. Carazolol was injected to enhance the placental dropping and also as a prophylactic measure to minimize the incidence of retained foetal membrane in the she-camel. Normal dropping of placenta engaged 49.27 +/- 6.76 minutes. In the treated animals the time needed for normal placental dropping was 33.00 +/- 10.05 minutes when injected with a prophylactic dose of carazolol. It was 38.89 +/- 8.07 minutes when the drug was injected in case of placental retention.

Adrenergic beta-Agonists↗

PubMed2000

Intraplacental choriocarcinoma with fetomaternal transfusion.

Intraplacental choriocarcinoma is very rare, and is usually found only after maternal and fetal metastatic disease is identified. The purpose of this case report is to review the incidence and findings of intraplacental choriocarcinoma. A term placenta was investigated because the newborn was born with severe anemia (Hb 3.0 g/dL). A 2 cm nodule was noted on the surface of the amniotic membrane and grossly resembled an infarction. The tumor was examined microscopically with immunohistochemical staining for the alpha- and beta-human chorionic gonadotropin (alpha-hCG, beta-hCG) subunits, human placental lactogen (hPL) and Ki-67. Microscopically, the tumor consisted of necrotic areas with proliferation of atypical trophoblastic cells and destruction of the villi and capillaries. The cells were positive for the alpha-hCG, beta-hCG subunits, hPL and Ki-67, consistent with intraplacental choriocarcinoma. The mother and newborn were investigated for the presence of metastatic disease. Computed tomography scans and magnetic resonance imaging of the mother and infant were negative for metastatic disease. Choriocarcinoma, limited only to the placenta with no evidence of metastatic disease is very rare. Primary intraplacental choriocarcinoma may frequently be overlooked or missed, and choriocarcinoma may possibly arise in the placenta more often than in retained or persistent trophoblast following pregnancy.

Adult↗

PubMed1987

Immunohistochemical localization of fibronectin in the human placentas at their different stages of maturation.

The distribution of fibronectin in the human placenta was studied by the aid of the immunoperoxidase technique using specific antibodies against it. In the early chorionic tissue, fibronectin was distributed along the trophoblastic basement membrane, on the wall of fetal blood vessels, in the connective tissue core, and in the cytotrophoblastic cell columns. In the term placenta, this glycoprotein was detected mainly on the fetal blood vessels and less intensely in the stroma, but not along the trophoblastic basement membrane. Endothelial cells of the blood vessels, fibroblastic cells in the stroma, and unidentified cells in the cytotrophoblastic cell columns were immunostained positively for fibronectin. These data suggest that fibronectin of the placenta is produced locally and retained in the tissue, if not all.

Antigens↗

PubMed1977

Ultrasonographic description of succenturiate placenta.

Postpartum hemorrhage may occur in cases of a retained succenturiate lobe. More catastrophic is rupture of the fetal vessels connecting the lobe to the placenta. A case is presented demonstrating the sonographic description of a large succenturiate lobe.

Adult↗

PubMed1992

[Morphology of the compensatory-adaptive responses in the placenta of multiparous women in uncomplicated pregnancy].

125 placentas of women with many (5-17) deliveries and 100 control placentas (with 1-2 deliveries) were studied morphologically. It is shown that placentas of women with 1-2 deliveries retain their structure, compensatory reactions are most active in the central part of the placenta. After 5-9 deliveries hemodynamic disturbances are observed, disorganization processes are less pronounced, the level of compensatory-adaptive processes increases. Hemodynamic disturbances and structural disorganization are observed after 10-17 deliveries with pronounced compensatory processes in the peripheral parts of the placenta. Dissociated disturbance of the villi maturation are revealed after numerous deliveries.

Adaptation, Physiological↗

PubMed2002

Red degeneration of a leiomyoma masquerading as retained products of conception.

BACKGROUND: The incidence of leiomyomas in pregnancy is approximately 1%. Their presence has been linked to spontaneous abortion, premature labor, soft tissue dystocia, uterine inertia, fetopelvic disproportion, malposition of the fetus, retention of the placenta, and postpartum hemorrhage. CASE: This case report documents a seldom-described event of a submucous leiomyoma masquerading as retained products of conception. The patient presented 4 weeks postpartum with complaints of urinary retention and heavy bleeding with cramping. Examination revealed a large mass resembling placental tissue filling the vaginal vault. The necrotic mass was removed with blunt and sharp dissection. The final pathology report revealed a degenerating leiomyoma. CONCLUSION: Complicating factors associated with this fibroid included a history of spontaneous abortion and preterm labor, as well as fetal malpresentation and carneous degeneration of the leiomyoma. Gestational myomas, although rare, can have an unusual appearance that may be misinterpreted.

Adult↗

PubMed1982

Whole-body autoradiography of 204Tl in embryos, fetuses and placentas of mice.

Whole-body autoradiography was used to study thallium uptake and retention in mice during gestation. Fifteen minutes after an intraperitoneal injection of 50 microCi 204Tl2SO4 into a 15-day pregnant mouse, thallium could be seen within the fetuses. Maximum fetal accumulation occurred 2-4 h after injection, and minimum at the last observation 4 days after injection. The fetal concentration of 204Tl was constantly lower than the placental. Uptake of 204Tl in embryos, fetuses and placentas of mice with gestation ages varying from 5 days to 16 days indicated that thallium crosses the placental barriers throughout gestation. Thallium was retained by the visceral yolk sac placenta during early gestation, by the visceral yolk sac, chorioallantoic placenta and amnion during late gestation. Over a period of time placental transfer and embryonic/fetal retention of small amounts of thallium may be hazardous to the offspring due to the high cumulative toxicity of this metal.

Animals↗

PubMed1991

Different combinations of regulatory elements may explain why placenta-specific expression of the glycoprotein hormone alpha-subunit gene occurs only in primates and horses.

Expression of the glycoprotein hormone alpha-subunit gene occurs in the pituitary of all mammals but in placenta of only primates and horses. In humans, two different elements, termed upstream regulatory element (URE) and cAMP response element (CRE), are required for placenta-specific expression of the alpha-subunit gene. The URE binds a protein unique to placenta whereas the CRE binds a ubiquitous protein. Comparative analysis of the promoter-regulatory region of the alpha-subunit gene from a number of mammals indicates that a functional URE has been retained and suggests the potential for placenta-specific expression. Indirect evidence also indicates that the URE-binding protein has been conserved, even in placenta from mammals that fail to express the alpha-subunit gene. Lack of expression of the alpha-subunit gene in placenta of rodents and cattle can be traced to a single nucleotide change that renders the CRE-like sequence of these genes incapable of binding the protein that confers responsiveness to cAMP. In contrast, although expression of the alpha-subunit gene occurs in horse placenta, the promoter-regulatory region lacks a functional CRE but appears to retain a functional URE. This suggests that either a different accessory element and cognate protein interacts with the horse URE to provide placenta-specific expression or that a completely different set of regulatory elements is required for placenta-specific expression in horses.

Animals↗

PubMed2006

Experimental methods to study human transplacental exposure to genotoxic agents.

Human placenta differs more than any other organ between species. This is the primary reason to develop models utilizing human tissue to study placental functions. There are no major ethical restrictions using human placenta for scientific studies. Also, the size of human placenta enables a great number of different parameters to be studied in one placenta. The most important cell types considering transplacental transfer, are the trophoblasts differentiating into syncytiotrophoblasts facing maternal circulation, and endothelial cells of fetal vessels. Primary trophoblasts are difficult to culture and do not grow in monolayer thus inhibiting studies on the polarized functions of transport. Several cell lines originating from trophoblasts have been developed, of which BeWo cells seem most useful for transport studies, because they grow in a tight monolayer. Placental tissue can also be retained as explant cultures, although the trophoblast viability is very restricted despite of culture conditions. Cotyledons of human placenta can be retained viable in an isolated organ perfusion. Perfused placental tissue stays viable longer than placental tissue in tissue culture. Although human placental perfusion is the most tedious experimental method to study placental functions, there are several good reasons to develop it further: transplacental transfer and molecular mechanisms of genotoxic compounds can be studied. Placental perfusion is the only experimental method that retains fully the structure of placenta for polarized transport. Furthermore, perfusion of placentas from mothers, who smoke, use illegal drugs or have a disease, allows studies on the impact of such factors on fetal exposure to genotoxic agents.

Cell Line↗

PubMed2000

Disseminated intravascular coagulopathy in pregnancy: thorough comprehension of etiology and management reduces obstetricians' stress.

In pregnancy and puerperium disseminated intravascular coagulopathy may accompany abruptio placenta, intrauterine fetal demise with retained dead fetus, amniotic fluid embolism, endotoxin sepsis, preecalampsia with HELLP and massive transfusion. Clinical signs and symptoms of DIC can include oozing from venipuncture sites and/or mucous membranes, red cell lysis from activation of the complement system, hemorrhage from coagulopathy and possible uterine atony, hypotension from hemorrhage and/or bradykinin release, and oliguria from end-organ insult and hypovolemia/hypotension. Treatment of DIC consists of replacement of volume, blood products, and coagulation components and cardiovascular and respiratory support with elimination of underlying triggering mechanism.

Disseminated Intravascular Coagulation↗

PubMed1985

Characterization of alkaline phosphatase from primordial germ cells and ontogenesis of this enzyme in the mouse.

The physical characteristics of nonspecific alkaline phosphatase (ALP) from both mouse primordial germ cells (PGCs) and gonads were compared with corresponding samples from other organs at different developmental stages. Combining a cytochemical approach with polyacrylamide gel electrophoresis and the use of specific inhibitors, as well as neuraminidase treatment, heat sensitivity tests, and molecular-mass criteria, it was found that only one ALP isoenzyme was present in all organs up to day 14 of gestation. Distinct ALP isoenzymes first appeared in the small intestine on day 15 and, thereafter, in all other tissues except the gonads. In these organs, the embryonal ALP isoenzyme seemed to be retained until adulthood. Although the placenta had a different ALP isoenzyme than the embryo at all stages, this isoenzyme was found to be similar to that in the maternal decidual tissues. Therefore, we conclude that the mouse embryo only expresses one type of ALP that can be considered "embryonal", regardless of the organ in which it first appears, and that this ALP is conserved in the gonads.

Alkaline Phosphatase↗