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At least 595 records · Page 33Linked to original sources
PubMed1997

Controlled cord traction versus minimal intervention techniques in delivery of the placenta: a randomized controlled trial.

OBJECTIVES: Our purpose was to compare the controlled cord traction technique with the minimal intervention technique for delivery of the placenta. The primary outcome was the incidence of postpartum hemorrhage. Secondary outcomes included duration of third stage of labor, frequency of retained placenta, hemorrhagic shock, the need for blood transfusion, and the need for uterotonic agents to control postpartum hemorrhage. STUDY DESIGN: A total of 1648 women who were delivered vaginally were randomly allocated during labor to the controlled cord traction group (n = 827) or the minimal intervention group (n = 821). In the controlled cord traction group women received oxytocin, 10 units intramuscularly, with delivery of the baby's anterior shoulder, after which the placenta was delivered actively by controlled cord traction (Brandt-Andrews method). In the minimal intervention group the placenta was delivered by maternal pushing. Continuous intravenous oxytocin was given after delivery of the placenta. Odds ratios with 95% confidence intervals were calculated for each variable. RESULTS: The overall incidence of postpartum hemorrhage was significantly lower in the controlled cord traction group (5.8% vs 11%; odds ratio 0.50, 95% confidence interval 0.34 to 0.73). The incidence of retained placenta (> or = 30 minutes) was 1.6% in the controlled cord traction group and 4.5% in the minimal intervention group (odds ratio 0.31, 95% confidence interval 0.15 to 0.63). Significantly more patients in the minimal intervention group required additional uterotonic agents to control hemorrhage (5.1% vs 2.3%; odds ratio 0.44, 95% confidence interval 0.24 to 0.78). CONCLUSION: The controlled cord traction technique for delivery of the placenta results in a significantly lower incidence of postpartum hemorrhage and retained placenta, as well as less need for uterotonic agents, compared with the minimal intervention technique.

Delivery, Obstetric↗
PubMed2001

Selective laser photocoagulation of communicating vessels in severe twin-twin transfusion syndrome in women with an anterior placenta.

BACKGROUND: We describe two techniques for the laser treatment of twin-twin transfusion syndrome in women with anterior placentas. TECHNIQUE: In the first technique, anastomoses were photocoagulated using a flexible endoscope through a single port. The second technique used a side-firing laser fiber with a rigid angled-view endoscope (two ports). EXPERIENCE: Seventy-two women had surgery between July 1997 and December 1999, 35 (48.6%) of whom had anterior placentas. Survival was similar for fetuses with anterior (80%) and posterior (75.6%) placentas, but operating time was significantly longer for those with anterior placentas (81.1 compared with 64.4 minutes for the anterior and posterior placentas, respectively; P = .02, Student t test). At least one fetus survived in 76% (16 of 21) of women treated with flexible endoscopes and 86% (12 of 14) of those treated with the side-firing lasers. Six of 72 women (8.3%) had patent vascular anastomoses on placental examination, and five of them had anterior placentas (P = .08, Fisher exact test). CONCLUSION: Although anterior placentas are surgically more challenging than posterior placentas, both techniques allow an effective percutaneous approach to the laser treatment of twin-twin transfusion syndrome.

Female↗
PubMedDate not supplied

Morphometry of the microvillous membrane of the human placenta in maternal diabetes mellitus.

The syncytiotrophoblast microvillous membrane of the human placenta has been investigated with quantitative analyses in a group of placentae from diabetic mothers, these placentae being compared to a group of normal placentae. This study has shown that, in the placentae of the diabetic mothers, there was a significant increase in the surface density of the microvilli and in the microvillous surface enlargement factor as compared to those of the controls. Consequently, it has demonstrated that the already large villous surface area found in the placentae of diabetic mothers can be enlarged very significantly by the microvilli, in terms of the total trophoblastic surface area which is in contact with the maternal blood. On a functional basis, these findings support the theory that placental function is probably not adversely affected in these placentae, and that these placentae can efficiently support the growth of large fetuses.

Female↗
PubMed1996

Cloning and sequencing of a copper-containing, topa quinone-containing monoamine oxidase from human placenta.

A 4040-bp cDNA was cloned from a human placenta library by screening with a polymerase chain reaction-amplified fragment. The fragment was generated from the library using primers corresponding to conserved sequences encompassing the topa quinone (TPQ) cofactor sites of the copper-containing proteins, bovine serum amine oxidase (BSAO) and human kidney diamine oxidase (DAO). The cloned cDNA contains a coding sequence from positions 161 to 2449. Between bases 2901 and 2974, in a very long 1591-bp 3'-untranslated region, there is a G/A-rich region in the minus strand, which contains a (AGG)5 tandem repeat. The human placenta cDNA sequence and its translated amino acid sequence are 84% and 81% identical to the corresponding BSAO sequences, while the identities for the placenta sequences and those for human kidney DAO are 60% and 41%, respectively. The TPQ consensus nucleotide and protein sequences are identical for the placenta enzyme and BSAO, but the corresponding sequences for human kidney DAO are nonidentical. Three His residues that have been identified as Cu(II) ligands in other amine oxidases are conserved in the human placenta amine oxidase protein sequence. It was concluded that the placenta cDNA open-reading frame codes for a copper-containing, TPQ-containing monoamine oxidase. A putative 19-amino acid signal peptide was identified for human placenta amine oxidase. The resulting mature protein would be composed of 744 amino acids, and would have a Mr of 82,525. Comparison of the human placenta amine oxidase with DNA sequences found in GenBank suggests that the gene for this enzyme is located in the q21 region of human chromosome 17, near the BRCA1 gene.

Amine Oxidase (Copper-Containing)↗
PubMed1992

The sonographically thick placenta: a predictor of increased perinatal morbidity and mortality.

In order to determine the prevalence and significance of sonographically thick placentas, we reviewed the computerized records of 18 827 viable, singleton pregnancies. Of these, 116 (0.6%) had thick placentas diagnosed by ultrasound examination. Perinatal mortality was markedly increased among pregnancies with thick placentas (odds ratio = 13.1, 95% confidence limits (CL) = 8.3-20.8), accounting for 6.2%; of the total. The rates of abruptio placentae (odds ratio = 2.9, CL = 1.1-8.1), neonatal intensive care unit admissions (odds ratio = 4.6, CL = 3.1-6.9) and anomalies (odds ratio = 8.4, CL = 4.9-14.4) were also significantly increased among the thick placenta cohort compared to controls. The 106 liveborn neonates with thick placentas had lower Apgar scores, were delivered at an earlier gestational age, and weighed less than controls. Anomalies, hydrops fetalis and abruptio placentae complicated 16 of the 24 cases of perinatal mortalities. Sonographically thick placentas should alert the clinician to the possibility of compromised perinatal outcome.

Journal Article↗
PubMed2001

Lysyl oxidases: expression in the fetal membranes and placenta.

The cross-linking of the connective tissues in the fetal membranes and placenta is important for their tensile strength and elasticity. We have studied the expression of lysyl oxidase (LOX) because it is the classical enzyme responsible for the cross-linking of collagen and elastin. We have also studied the two recently described, genetically distinct lysyl oxidase-like genes and proteins, lysyl oxidase-like (LOXL) and lysyl oxidase-like 2 (LOXL2), of unknown functions. Specific antisera have been used for immunolocalization in fetal membranes and placentae from early pregnancy terminations and after caesarean section at both preterm and term, prior to labour. In addition, the steady state mRNA levels of the three genes has been quantitated in separated amnion, chorion, decidua and placentae collected at term before labour. The immunocytochemistry shows that the spatial expression of the three lysyl oxidases is similar in early pregnancy in both the fetal membranes and placentae. However, by preterm this pattern had diverged and becomes greatest at term. The expression of the genes found at term was similar to the results of protein expression obtained by immunocytochemistry, with the exception of LOXL which had high placental gene expression, but low levels of immunolocalized protein. Thus by term, LOX was expressed predominantly in the amniotic epithelium, with little expression in the placenta, while LOXL showed highest gene expression in the placenta and lowest expression in the amnion. LOXL2 expression was again different and was expressed predominantly in the chorionic cytotrophoblast of the membranes with low expression in both the amnion and placentae. These results suggest that these three members of the lysyl oxidase family may have similar roles in early pregnancy during the development of the placenta and fetal membranes, but their divergence as pregnancy advances to term, may reflect changes in substrate specificity and connective tissue composition.

Abortion, Legal↗
PubMed2003

Apoptosis and related proteins in placenta of intrauterine fetal death in prostaglandin f receptor-deficient mice.

The present study investigated whether the increase of apoptosis in the placenta is associated with intrauterine fetal death in prostaglandin F receptor-deficient mice. Apoptosis was demonstrated within placental and decidual tissue by the TUNEL method. The majority of apoptosis was found in syncytiotrophoblast tissues. Enhanced TUNEL-positive staining in the syncytiotrophoblast layer was scattered in the placental tissues in clusters of apoptotic cells in the death group. Marked TUNEL-positive cells were identified in decidua of both groups. The rate of apoptosis in the placenta and decidua in the death group was higher than that in the survival group (P < 0.05). Immunohistochemical analysis showed that the level of active caspase-3 protein expression in the placenta in the death group was much higher than that in the survival group. The level of Bcl-2 protein expression in the placenta in the death group was much lower than that in the survival group. Western blot analysis demonstrated that increased expression of the active form of caspase-3 was detected in the placenta and decidua in the death group compared with that in the survival group. In contrast, a decrease in the expression of Bcl-2 was detected in the placenta and decidua in the death group compared with that in the survival group. Enhanced expression of Bax:Bcl-2 ratio was detected in placenta and decidua in the death group compared with that in the survival group. Thus, significantly increased apoptosis in the mouse placenta and decidua might be involved in the pathophysiologic mechanism of intrauterine fetal death.

Animals↗
PubMedDate not supplied

Fractal analysis of placenta mature villi in healthy, smoking and non-smoking women.

Not all the objects created by nature can be described by means of the classical Euclidean geometry rules. New, quickly developing fractal theory can provide another instrument for describing irregular surfaces of e.g. geometric structures and objects whose development results from growth, differentiation and degeneration processes. In the present study we decided to perform fractal analysis of mature, terminal villi of placenta taken from smoking and non-smoking women, during the third trimester of pregnancy. The aim of this study was to find another morphometric parameter, independent of subjective factors, which would provide new information about the studied structure. Placentas were taken from healthy women, untreated primiparas, who did not undergo any hormonal treatment, aged 18 to 27. The material was divided into: control group--placentas from non-smoking women, and two experimental groups--placentas from non-smoking up to 30 cigarettes daily and placentas from women smoking up to 30 cigarettes daily and placentas from women smoking over 30 cigarettes daily. Fractal dimension was determined by three methods: box counting, dilation and mass scaling method. Taking under consideration the results obtained in the present study it seems that fractal dimension, objectively and independently of many factors, allows to perform mathematical estimation of the parameter which is the terminal villi occurrence density within placenta. Among the applied fractal analysis methods, used for placenta terminal villi density grade estimation, the most useful seems to be the box counting method, whereas for estimating villi surface complication--the ratio--mass scaling method. Comparing obtained fractal dimension results, we have found that they increase together with the amount of cigarettes smoked during pregnancy.

Adolescent↗
PubMedDate not supplied

Study of placenta of children born with congenital malformations.

The malformations in this study were observed in a series of 279,642 consecutive births of known outcome registered in our Registry of congenital anomalies. For each case, more than 50 factors included in the registration forms were studied. One of the factors studied was the placenta. For each malformed child, a control was chosen. Cases with maternal known factors impairing placenta function, i.e. vasculopathy and diabetes, were excluded. In each category of malformations studied, the malformed children were divided into isolated and non-isolated (multiple malformed) cases. The weight of placenta of isolated cases was not lower than the weight of placenta of the controls. In contrast, the weight of placenta of the cases with non-isolated malformations was lower than the weight of placenta of the controls and of the isolated cases, for all categories of malformations but gastroschisis and omphalocele. The mean weights at birth of the cases with multiple malformations were also lower than those of the controls. The human placenta discounts a principal functional part, the maternal blood in the intervillous space. Congenital malformations may interact with this function.

Birth Weight↗
PubMed2004

Poly(ADP-ribose) glycohydrolase in bovine retained and not retained placenta.

Poly(ADP-ribose) glycohydrolase (PARG) is the enzyme which degrades poly(ADP-ribose) polymers synthesized by poly(ADP-ribose) polymerase (PARP). Both enzymes are activated in response to different stimuli like oxidative stress and are involved in DNA repair processes. The retention of bovine foetal membranes (RFM) is supposed to be connected with oxidative stress conditions. The aim of the study was to detect the presence of PARG protein in bovine placenta in order to find the relationship between the process of releasing, retaining placenta and DNA repair. Placentomes, collected alter spontaneous delivery or caesarian section were divided into maternal as well as foetal part of placenta, homogenized and subjected to electrophoresis. Animals were divided into six groups as follows: A--caesarian section before term with RFM; B--caesarian section before term without RFM; C--spontaneous delivery at term with RFM; D--spontaneous delivery at term without RFM; E--caesarian section at term with RFM; F--caesarian section at term without RFM. PARG protein was detected in nitrocellulose membranes using commercially available bovine anti-PARG antibody and Western blotting technique. Single bands referred to bovine PARG standard were observed in all examined tissues as well as in human placenta used as the control of procedure. In addition, the intensity of staining was stronger in retained than properly released term placenta and in foetal than in maternal part of the placenta. These results may suggest the differences in enzyme protein content and careful conclusions can be drawn that the activities of PARG may be altered between compared groups of animals. It may confirm the presence of oxidative stress conditions and their consequences on metabolic pathways, the content of biologically active substances and processes of proper releasing placenta. Further experiments on PARG activity in bovine foetal membranes with respect to proper and improper placental release are necessary.

Animals↗
PubMed1998

Diagnosis and management of placenta percreta: a review.

A review of the clinical decisions, diagnostic, and surgical methods in managing patients with placenta percreta was done by conducting a MEDLINE computerized search from January 1991 to January 1997 using the key words "placenta percreta," "placenta previa," "acute normovolemic hemodilution," and "erythropoietin use." Additional sources were identified through cross-referencing. We reviewed all published reports and articles regarding the clinical and surgical management of placenta percreta and nontraditional ways to treat or prevent anemia in these cases (including acute normovolemic hemodilution and erythropoietin use). The diagnosis of placenta percreta using different ultrasonographic criteria is reliable. Clinical and surgical methods of managing placenta previa with a high risk of percreta are all based on prevention of uncontrolled hemorrhage. Ninety percent of these patients will lose more than 3000 ml intraoperatively and will require blood transfusion. To avoid serious maternal morbidity secondary to hypovolemia, several options are available: erythropoietin use, acute normovolemic hemodilution, selective arterial embolization, prophylactic uterine, or hypogastric artery ligation. With the increasing incidence of placenta percreta, the clinician must use all available methods to accurately diagnose this condition. Adequate preparation and good surgical technique will help reduce maternal mortality and morbidity related to this condition.

Erythropoietin↗
PubMed2002

Risk factors for placenta praevia in southern Nigeria.

OBJECTIVE: To determine the risk factors for placenta praevia in Ile-Ife, southern Nigeria. DESIGN: A prospective case control study. SETTING: A tertiary center--Obafemi Awolowo University Teaching Hospital, Ile-Ife, southern Nigeria. SUBJECTS: One hundred and thirty six patients with confirmed placenta praevia constituted the cases. Controls consisted of one hundred and thirty six patients who delivered at term immediately after each indexed case and did not have placenta praevia. RESULTS: Cases and controls were similar in terms of twin deliveries (P = 0.72) and past history of uterine surgery (P = 0.47). After adjusting for confounders, factors associated with risk of placenta praevia were history of retained placenta [OR = 6.7(95% CI 1.2-36.6)], previous caesarean section [OR = 4.7, (95% CI 1.9-11.4)], previous abortion [OR = 2.9 (95% CI 1.1-5.1)], grand multiparity [OR = 2.1 (95% CI 1.6-7.1)] and age over 35 years [OR = 1.4 (95% CI 1.2-6.6)]. CONCLUSIONS: From our study, the risk factors for placenta praevia are a history of retained placenta, previous caesarean section, previous abortion, grand multiparity and maternal age over 35 years.

Abortion, Induced↗
PubMed2005

A small-angled thin edge of the placenta predicts abnormal placentation at delivery.

OBJECTIVE: This study was intended to determine the relationship between the angle of the lower placental edge in early pregnancy and the previa/low-lying placenta at delivery. METHODS: We used transvaginal sonography to consecutively screen 2543 singleton pregnancies. All subjects were scanned during the period of gestation between 12 weeks 0 days and 15 weeks 6 days. The angle of the lower placental edge was measured when the placenta covered the internal cervical os. These cases were followed sonographically until term. RESULTS: Of 168 cases in which the internal cervical os was covered at screening, 9 showed previa/low-lying placenta at delivery (previa/low-lying group). The remaining 159 showed no abnormal placentation (nonprevia group). There were significantly fewer degrees of angle in the previa/low-lying group than in the nonprevia group (P < .05). For the previa/low-lying group, the arithmetic mean, median, and SD values of the angles were 60.8 degrees , 50.0 degrees , and 9.8 degrees , respectively. For the nonprevia group, those values were 103.4 degrees , 103.0 degrees , and 31.8 degrees , respectively. Data based on the cutoff number of the angle of 74 degrees indicated the following: sensitivity of placenta previa or low-lying placenta at term, 100% (9 of 9); false-positive rate, 23% (36 of 159); positive predictive value, 20% (9 of 45); and negative predictive value, 100% (123 of 123). CONCLUSIONS: The angle between the placental-uterine interface and fetal placental surface can be evaluated during early pregnancy. It appears to accurately predict placenta previa or low-lying placenta at term gestation with a sensitivity of 100%, a false-positive rate of 23%, and a high negative predictive value of 100%, which would allow for elimination of some of the multiple scans.

Delivery, Obstetric↗
PubMed1991

Placenta previa percreta involving the urinary bladder: a report of two cases and review of the literature.

The incidences of both placenta previa and placenta accreta are increased in patients with scarred uteri, and patients with uterine scars and placenta previa are at increased risk for also having placenta accreta. Two cases are presented of placenta previa percreta with involvement of the urinary bladder necessitating cesarean hysterectomy, partial cystectomy, and, in one case, bilateral ureteral reimplantation. Both patients had two previous cesarean deliveries. Serious hemorrhage is common in patients with placenta percreta. The primary goal of surgical management must be to control bleeding, which usually requires resection of all tissue involved by the infiltrating placenta. After hemorrhage is controlled, the surgeon must reestablish the integrity of the urinary system and reconstruct the pelvis as necessary.

Adult↗
PubMed1976

[Does the site of the placenta in the area of the caudal section of the uterus change during pregnancy? An echographic observation of the course of pregnancy (author's transl)].

Via examinations by ultrasonic sectional view during the course of pregnancy, the growth of the placenta was followed in 52 pregnant women. When a pathologic location of the placenta could be excluded during the first examination in the second trimester (26 cases), secondary development of a pathologic insertion was not observed. In 26 cases in which a pathological location of the placenta could be established before the 20th gestation week, a cranial shift in the caudal placenta border of up to 8 cm could be established in 19 cases. A pathological location of the placenta diagnosed in the second trimester can disappear. The shape of the uterus and the alterations in the spacial relationship between placenta and internal os uteri were caused by the development and stretching of the lower segment of the uterus. The vaginal hemorrhages in the second trimester caused by a low placental insertion (13 cases) stopped (with the exception of 2 cases) at the latest after the 6th month of pregnancy. The definitive establishment of a placenta pravia before the 5th-6th month of pregnancy is virtually impossible sonographically.

Female↗
PubMed1998

Expression of the insulin-like growth factors and their receptors in term placentas: a comparison between normal and IUGR births.

Intrauterine growth retardation (IUGR) is defined as growth retarded to be below the tenth centile. The insulin-like growth factors and their receptors are implicated in pre- and postnatal growth and development, and it is believed that alteration in their activity may contribute to IUGR. In this study nine normal and nine intrauterine growth retarded births were followed and term placentas examined for expression of the insulin-like growth factors and their receptors. It was found that the expression of insulin-like growth factor 1 (IGF1), insulin-like growth factor 2 (IGF2), and the insulin, IGF1 and IGF2 receptor transcripts (IGF1R and IGF2R, respectively) was present in all term placentas examined. Expression of insulin was not detected. Quantitative polymerase chain reaction (PCR) was used to compare transcription levels in term placentas from normal with IUGR births. There was no significant difference in the levels of transcripts for IGF1, insulin receptor, or IGF2R between normal and IUGR term placentas. However, the IUGR term placentas had significantly higher levels of IGF2 and IGF1R expression compared with the normal term placentas. The increase in the transcription of IGF2 and IGF1R in IUGR term placentas may represent a counter regulatory mechanism in response to the growth retardation.

Adult↗
PubMed2000

Comparative analysis of HOXC-9 gene expression in murine hemochorial and caprine synepitheliochorial placentae by in situ hybridization.

Mammalian placentae exhibit wide structural diversity among different species and are formed under intricate interplay between the embryonic trophoblast and the maternal endometrial cells. Increasing evidence in the literature indicates a possible role played by homeobox genes in the complex placental organogenesis. Although the expression of all HOX 9 paralogs has been demonstrated both in highly invasive murine hemochorial placentae and in non-invasive caprine synepitheliochorial placentae, no reports so far published in the literature described the patterns of gene expression of Hoxc-9 in the murine nor those of HOXC-9 in the caprine placenta at cellular levels. We carried out comparative analyses of the location and identity of the cells expressing Hoxc-9/HOXC-9 during various stages of placentation in the murine hemochorial and caprine synepitheliochorial placentae by means of in situ hybridization using murine Hoxc-9 or caprine HOXC-9 cRNA probe, respectively. The results demonstrated that Hoxc-9 mRNA was expressed at high levels in giant trophoblast cells of murine placentae on Days 12-19, but not on Day 8. Similar analysis of caprine Day 75 and Day 100 placentae revealed that the binucleate trophoblast cells that penetrate the uterine luminal epithelial cell layer, strongly expressed HOXC-9 mRNA. Although the functional significance of Hoxc-9/HOXC-9 gene expression in trophoblast cells remains to be elucidated, it was suggested that it might play a role in the regulation of invasiveness or endocrine activities in the murine giant trophoblast cells and/or the caprine binucleate trophoblast cells.

Age Factors↗
PubMed1975

Fine structural observations on hemopoiesis in the chorioallantoic placenta of the marmoset.

Hemopoietic sinuses in the chorionic trabeculae of marmoset placenta were examined electron microscopically at several stages of pregnancy. Tissues were prepared both by standard technique and following injection of exogenous peroxidase into the maternal circulation prior to autopsy, and subsequent cytochemical localization of its reaction product in the fetal placenta. Aside from their dilated size and cellular content, the sinuses resembled the allantoic capillaries of the peripheral umbilical circulation in this species; and in early and midgestational placentas, sinusal lumina, differentiating elements in the erythroid line were present in placentas at all stages. Such cells appeared to arise both by a process of proliferation of undifferentiated progenitors from the sinusal lining and by mitosis of pre-existing erythroid cells. Only the latter process was observed in the mature placenta near term. Granulopoiesis was not observed at any stage; on the other hand, cells in the thromboid line were identified in placentas believed to be near midgestation; and large intrasinusal phagocytes were present in both midgestational and late placentas. In the latter, they were seen to have endocytosed peroxidase, and, by tenuous, dendriform processes, to be related anatomically to large numbers of erythroid cells. Early in gestation, the developing erythroid elements were closely related by areas of contact, both to each other and to the delimiting endothelium of the sinuses.

Allantois↗