Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 78
Filtrar
1.
Ultrasound Obstet Gynecol ; 62(2): 248-254, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36971026

RESUMO

OBJECTIVE: To examine the relationship between umbilical cord insertion site, placental pathology and adverse pregnancy outcome in a cohort of normal and complicated pregnancies. METHODS: Sonographic measurement of the cord insertion and detailed placental pathology were performed in 309 participants. Associations between cord insertion site, placental pathology and adverse pregnancy outcome (pre-eclampsia, preterm birth, small-for-gestational age) were examined. RESULTS: A total of 93 (30%) participants were identified by pathological examination to have a peripheral cord insertion site. Only 41 of the 93 (44%) peripheral cords were detected by prenatal ultrasound. Peripherally inserted cords were associated significantly (P < 0.0001) with diagnostic placental pathology (most commonly with maternal vascular malperfusion (MVM)); of which 85% had an adverse pregnancy outcome. In cases of isolated peripheral cords, without placental pathology, the incidence of adverse outcome was not statistically different when compared to those with central cord insertion and no placental pathology (31% vs 18%; P = 0.3). A peripheral cord with an abnormal umbilical artery (UA) pulsatility index (PI) corresponded to an adverse outcome in 96% of cases compared to 29% when the UA-PI was normal. CONCLUSIONS: This study demonstrates that peripheral cord insertion is often part of the spectrum of findings of MVM disease and is associated with adverse pregnancy outcome. However, adverse outcome was uncommon when there was an isolated peripheral cord insertion and no placental pathology. Therefore, additional sonographic and biochemical features of MVM should be sought when a peripheral cord is observed. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Placenta , Resultado da Gravidez , Cordão Umbilical , Feminino , Humanos , Recém-Nascido , Gravidez , Placenta/patologia , Nascimento Prematuro , Artérias Umbilicais/diagnóstico por imagem , Cordão Umbilical/diagnóstico por imagem , Cordão Umbilical/patologia
3.
Ultrasound Obstet Gynecol ; 58(6): 824-836, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34097323

RESUMO

OBJECTIVES: To characterize, using magnetic resonance imaging (MRI), the distribution of blood flow and oxygen transport in human fetuses with subtypes of congenital heart disease (CHD) that present with neonatal cyanosis. METHODS: Blood flow was measured in the major vessels of 152 late-gestation human fetuses with CHD and 40 gestational-age-matched normal fetuses, using cine phase-contrast MRI. Oxygen saturation (SaO2 ) was measured in the major vessels of 57 fetuses with CHD and 40 controls. RESULTS: Compared with controls, we found lower combined ventricular output in fetuses with single-ventricle physiology, with the lowest being observed in fetuses with severe forms of Ebstein's anomaly. Obstructive lesions of the left or right heart were associated with increased flow across the contralateral side. Pulmonary blood flow was reduced in fetuses with Ebstein's anomaly, while those with Ebstein's anomaly and tricuspid atresia had reduced umbilical flow. Flow in the superior vena cava was elevated in fetuses with transposition of the great arteries, normal in fetuses with hypoplastic left heart, tetralogy of Fallot or tricuspid atresia and reduced in fetuses with Ebstein's anomaly. Umbilical vein SaO2 was reduced in fetuses with hypoplastic left heart or tetralogy of Fallot. Ascending aorta and superior vena cava SaO2 were reduced in nearly all CHD subtypes. CONCLUSIONS: Fetuses with cyanotic CHD exhibit profound changes in the distribution of blood flow and oxygen transport, which result in changes in cerebral, pulmonary and placental blood flow and oxygenation. These alterations of fetal circulatory physiology may influence the neonatal course and help account for abnormalities of prenatal growth and development that have been described in newborns with cyanotic CHD. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Cianose/diagnóstico por imagem , Feto/diagnóstico por imagem , Cardiopatias Congênitas/diagnóstico por imagem , Imageamento por Ressonância Magnética , Diagnóstico Pré-Natal/métodos , Estudos de Casos e Controles , Cianose/embriologia , Anomalia de Ebstein/diagnóstico por imagem , Anomalia de Ebstein/embriologia , Feminino , Feto/irrigação sanguínea , Feto/embriologia , Idade Gestacional , Cardiopatias Congênitas/embriologia , Hemodinâmica , Humanos , Recém-Nascido , Masculino , Saturação de Oxigênio , Circulação Placentária , Gravidez , Atresia Tricúspide/diagnóstico por imagem , Atresia Tricúspide/embriologia
4.
Ultrasound Obstet Gynecol ; 57(3): 409-416, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33073889

RESUMO

OBJECTIVE: The value of using customized birth-weight centiles to improve the diagnostic accuracy for fetal growth restriction (FGR), in comparison with using population-based charts, remains a matter of debate. One potential explanation for the conflicting data is that most studies used measures of perinatal mortality and morbidity as proxies for placenta-mediated FGR, many of which are not specific and may be confounded by other factors such as prematurity. The aim of this study was to compare the diagnostic accuracy of small-for-gestational age (SGA) at birth, defined according to customized vs population-based charts, for associated abnormal placental pathology. METHODS: This was a secondary analysis of data from a prospective cohort study on risk factors for placenta-mediated complications and abnormal placental pathology in low-risk nulliparous women. All placentae were sent for detailed histopathological examination by two perinatal pathologists. The primary exposure was SGA, defined as birth weight < 10th centile for gestational age using either a customized (SGAcust ) or a population-based (SGApop ) birth-weight reference. The outcomes of interest were one of three types of abnormal placental pathology associated with FGR: maternal vascular malperfusion (MVM), chronic villitis and fetal vascular malperfusion (FVM). Adjusted relative risks (aRR) with 95% CIs were estimated using modified Poisson regression analysis, with adjustment for smoking, body mass index and aspirin treatment. RESULTS: A total of 857 nulliparous women met the study criteria. The proportions of infants identified as SGA based on the customized and population-based charts were 12.6% (108/857) and 11.4% (98/857), respectively. A diagnosis of SGA using either customized or population-based charts was associated with an increased risk of any placental pathology (aRR, 3.04 (95% CI, 2.29-4.04) and 1.60 (95% CI, 1.10-2.31), respectively) and MVM pathology (aRR, 12.33 (95% CI, 6.60-23.03) and 5.29 (95% CI, 2.87-9.76), respectively). SGAcust , but not SGApop , was also associated with an increased risk for chronic villitis (aRR, 1.85 (95% CI, 1.07-3.18)) and FVM pathology (aRR, 2.48 (95% CI, 1.25-4.93)). SGAcust had a higher detection rate for any placental pathology (30.3% vs 17.1%; P < 0.001), MVM pathology (63.2% vs 39.5%; P = 0.003) and chronic villitis (20.8% vs 8.3%; P = 0.007) than did SGApop , for a similar false-positive rate. This was mainly the result of a higher detection rate for abnormal pathology in the white and East-Asian subgroups and a lower false-positive rate for abnormal pathology in the South-Asian subgroup by SGAcust than by SGApop . In addition, pregnancies in the SGAcust group, but not those in the SGApop group, were more likely to be complicated by preterm birth and a low 5-min Apgar score than were the corresponding non-SGA group. CONCLUSION: These findings suggest that customized birth-weight centiles may be superior to population-based birth-weight centiles in detecting FGR that is due to underlying placental disease. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Peso ao Nascer , Retardo do Crescimento Fetal/diagnóstico , Gráficos de Crescimento , Doenças Placentárias/diagnóstico , Diagnóstico Pré-Natal/estatística & dados numéricos , Adulto , Índice de Apgar , Feminino , Desenvolvimento Fetal , Retardo do Crescimento Fetal/etiologia , Idade Gestacional , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Doenças Placentárias/epidemiologia , Gravidez , Diagnóstico Pré-Natal/métodos , Estudos Prospectivos
5.
Ultrasound Obstet Gynecol ; 57(1): 70-74, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33030756

RESUMO

OBJECTIVE: To evaluate the feasibility of using umbilical artery (UA) Doppler waveforms to measure fetal heart rate (FHR) short-term variation (STV) across gestation. METHODS: This was a prospective longitudinal study, conducted at two study sites, of 195 pregnancies considered low risk. Pulsed-wave Doppler of the UAs was performed at 4-weekly intervals, between 14 and 40 weeks of gestation, using a standardized imaging protocol. Up to 12 consecutive UA Doppler waveforms were analyzed using offline processing software. FHR STV was calculated using average R-R intervals extracted from the waveforms and baseline corrected for FHR. RESULTS: Baseline-corrected FHR STV increased significantly with gestational age (conditional R2 = 0.37; P < 0.0001) and was correlated inversely with FHR (conditional R2 = 0.54; P < 0.0001). The STV ranged (median (interquartile range)) from 3.5 (2.9-4.1) ms at 14-20 weeks' gestation to 6.3 (4.8-7.7) ms at 34-40 weeks' gestation. The change in heart rate STV did not differ between study sites or individual sonographers. CONCLUSIONS: UA Doppler waveforms offer a robust and feasible method to derive STV of the FHR. It should be emphasized that the UA Doppler-derived STV is not interchangeable with measurements derived with computerized cardiotocography. Accordingly, further investigations are needed to validate associations with outcome, in order to determine the value of concurrent fetal cardiovascular and heart rate evaluations that are possible with the technique described here. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Retardo do Crescimento Fetal/diagnóstico por imagem , Frequência Cardíaca Fetal , Artéria Cerebral Média/diagnóstico por imagem , Ultrassonografia Doppler/métodos , Artérias Umbilicais/diagnóstico por imagem , Adulto , Cardiotocografia/métodos , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Estudos Longitudinais , Masculino , Artéria Cerebral Média/embriologia , Gravidez , Estudos Prospectivos , Ultrassonografia Pré-Natal
7.
J Thromb Haemost ; 2018 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-29877031

RESUMO

Pre-eclampsia, a hypertensive disorder of pregnancy, continues to be a significant cause of global maternal morbidity. Low-dose aspirin remains the only standard-of-care prophylactic therapy for preventing pre-eclampsia, but is limited in efficacy. Heparin and its derivatives may further enhance the efficacy of aspirin therapy to prevent pre-eclampsia, but the mechanisms mediating this augmentative effect are not known. Although heparin is an anticoagulant agent, it also possesses many anticoagulant-independent properties that may be relevant in the prevention of pre-eclampsia, including effects on placental, vascular and inflammatory function. This review summarizes the non-anticoagulant properties of heparin, and extrapolates how these actions may influence the trajectory of pre-eclampsia pathogenesis as a means of pathway-specific therapy.

9.
Placenta ; 34(7): 606-12, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23628505

RESUMO

INTRODUCTION: Small ubiquitin-like modifiers (SUMO) conjugate to target proteins in a dynamic, reversible manner to function as post-translational modifiers. SUMOylation of target proteins can impinge on their localization, in addition to their activity or stability. Differential expression of deSUMOylating enzymes (SENP 1 and 2) contributes to altered mammalian placental development and function in mice. Severe preeclampsia (sPE) is associated with abnormal placental development and chronic ischemic injury. Extra- and intracellular stimuli/stressors that include hypoxic-activated pathways are known modulators of SUMOylation. In this current study we hypothesized that placentas from sPE patients will display up regulation in the SUMO regulatory pathway. METHODS: Utilizing qRT-PCR, immuno-blotting and Western techniques, we determined the expression levels of SUMO pathway genes in healthy and diseased placentas. We also exposed placental explants to hypoxia to study the effect on the SUMOylation pathway. RESULTS: We observed steady-state expression of SUMO1-3, SUMO-conjugated enzyme-UBC9 and deSUMOylating enzymes - SENPs, throughout normal gestation. An elevated level of free SUMO1-3 and SUMO-protein conjugates was observed in sPE placentas. Furthermore, placental UBC9 levels were strikingly increased in the same sPE patients. Hypoxia-induced SUMOylation in first trimester placental explants. DISCUSSION: Our data demonstrate an elevated steady-state of SUMOylation in sPE placentas compared with gestational aged-matched controls. The observed hyper-SUMOylation in sPE placentas correlates with elevated expression of UBC9 rather than with reduced expression of SENPs Hypoxia may contribute to alterations in placental SUMOylation pathway. CONCLUSION: Increased placental SUMOylation may contribute to the pathogenesis of serious placental pathology that causes extreme preterm birth.


Assuntos
Placenta/metabolismo , Pré-Eclâmpsia/fisiopatologia , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Sumoilação , Enzimas de Conjugação de Ubiquitina/biossíntese , Feminino , Humanos , Hipóxia/fisiopatologia , Gravidez , Primeiro Trimestre da Gravidez , Segundo Trimestre da Gravidez
10.
Ultrasound Obstet Gynecol ; 42(3): 315-21, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23288860

RESUMO

OBJECTIVES: To determine the pathological basis and clinical associations of excessively thick placentae observed at second-trimester ultrasound examination. METHODS: In a retrospective cohort of 19 singleton high-risk second-trimester pregnancies noted to have a placental length-to-maximum thickness ratio ≤ 2.0, maximum sonographic placental thickness was correlated with clinical outcome, maximum placental thickness after delivery and placental pathological findings. Results were compared with those of an intermediate group of 21 high-risk pregnancies with normal placental dimensions and a control group of 18 low-risk pregnancies also with normal placental dimensions. Increased maximum placental thickness (> 28 mm) and abnormal placental deflation following delivery (pathology - sonography difference in maximum placental thickness < -2 mm) were defined by the upper and lower quartile values, respectively, in the control group. RESULTS: The study group exhibited significantly more adverse outcomes and gross pathological placental features compared with both intermediate and control groups. Despite increased sonographic maximum placental thickness in the study group (median, 55 (range, 40-75) mm compared with both the intermediate group (median, 27 (range, 22-41) mm, P < 0.0001) and the control group (median 26 (range, 23-36) mm, P < 0.0001)), all three groups had similar maximal placental thickness following delivery (study group: median, 24 (range, 10-50) mm vs intermediate group: median, 27 (range, 15-40) mm, P = 0.82 and vs control group: median, 28.5 (range, 18-44), P = 0.42). Pathology-sonography difference in maximum placental thickness in the study group (median, -30 (range, -42 to 0) mm) was significantly greater than that in either the intermediate (median, -2 (range, -11 to 9) mm, P < 0.0001) or the control (median, 1.5 (range, -10 to 18) mm, P < 0.0001) group and was significantly associated with abnormal development of the gas-exchanging placental villi (distal villous hypoplasia) (P = 0.0001). CONCLUSIONS: Increased second-trimester sonographic maximum placental thickness represents a pathological finding associated with severe adverse perinatal outcome. This observation is due to overinflation of the intervillous space by maternal blood rather than to adaptive formation of functional placental tissue.


Assuntos
Retardo do Crescimento Fetal/epidemiologia , Placenta/patologia , Nascimento Prematuro/epidemiologia , Adolescente , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade , Placenta/diagnóstico por imagem , Gravidez , Resultado da Gravidez , Segundo Trimestre da Gravidez , Gravidez de Alto Risco , Estudos Retrospectivos , Ultrassonografia Pré-Natal/métodos , Adulto Jovem
11.
Placenta ; 34(1): 62-6, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23174148

RESUMO

OBJECTIVE: The aims of this study were to develop a nomogram of umbilical cord diameter (UCD) for pathologic examination of the placenta, to identify the umbilical cord components responsible for variations in UCD, and to examine the relationship between UCD and other placental pathologic features and perinatal outcome. STUDY DESIGN: We prospectively collected 497 umbilical cords between 18 and 41 weeks' gestation over a 1-year period. Fresh-tissue UCD were grouped according to gestational age and compared to sonographic and histological measurements. Associations between UCD percentile and placental pathologic findings or obstetrical outcomes were examined. RESULTS: Mean UCD increased with gestational age until a plateau at 1.0 cm in the third trimester, a value that was 0.56 cm less than sonographic measurements prior to delivery and 0.17 cm greater than UCD measured histologically. Umbilical cord components varied with UCD percentile, with umbilical vessel area increased in thick cords (p < 0.001) and Wharton's jelly area reduced in thin cords (p = 0.002). Thin umbilical cords were associated with at least one pathologic histological placental finding (p = 0.02), low placental weight (p < 0.001), single umbilical artery (p = 0.02), marginal cord insertion (p = 0.01), and low infant birth weight (p < 0.001). CONCLUSIONS: This study provides reference curves for post-delivery UCD from 18 to 41 weeks' gestation for use by perinatal pathologists. We show that increased UCD is a function of increased umbilical blood vessel volume and decreased UCD is a function of decreased Wharton's jelly volume. UCD shows a strong association with placental and infant birth weight.


Assuntos
Peso ao Nascer/fisiologia , Doenças Placentárias/patologia , Cordão Umbilical/anatomia & histologia , Cordão Umbilical/patologia , Estudos de Coortes , Feminino , Idade Gestacional , Gráficos de Crescimento , Humanos , Recém-Nascido , Tamanho do Órgão , Doenças Placentárias/etiologia , Gravidez , Resultado da Gravidez , Prognóstico , Cordão Umbilical/crescimento & desenvolvimento , Geleia de Wharton/crescimento & desenvolvimento , Geleia de Wharton/patologia
12.
Placenta ; 33(7): 568-71, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22513321

RESUMO

OBJECTIVES: Since pregnancies with a male fetus have higher perinatal complications attributed to placental dysfunction, including severe pre-eclampsia and intrauterine growth restriction, the objective of our study was to formally evaluate placental pathology for a placental origin of these sex-specific differences. DESIGN: Retrospective study at Mount Sinai Hospital in Toronto, Canada. Identification of 262 singleton pregnancies affected by severe pre-eclampsia and/or intrauterine growth restriction who delivered between 22 and 32 weeks' gestation from 2000 to 2010. Detailed placental pathology was reviewed, and data from 140 pregnancies with male fetuses were compared with 122 pregnancies with female fetuses. A comparison group of 40 unaffected pregnancies who delivered in the same gestational range was used to determine baseline rates of placental pathology. MAIN OUTCOME MEASURED: Detailed placental pathology, including placental development/differentiation, velamentous umbilical cord insertion, maternal-fetal interface pathology, villous infarction, hemorrhagic lesions, villous development, and fetal vascular under-perfusion. RESULTS: Impaired placental development and differentiation was equally common amongst males (73/140, 52.1%) and females (69/122, 56.6%). Male placentas exhibited significantly higher rates of chronic deciduitis (17.9% vs. 9.0%; relative risk [RR] 1.98, 95% confidence interval [CI] 1.02-3.86) and velamentous umbilical cord insertion (9.5% vs. 1.7%; RR 5.66, 95% CI 1.30-24.6), and a significantly lower frequency of villous infarction (55.4% vs. 73.7%; RR 0.75, 95% CI 0.62-0.90) than female placentas. No significant differences were noted for other lesions. CONCLUSIONS: Fetal sex exerts a differential effect on the placental pathology that mediates severe pre-eclampsia and/or IUGR. Placental pathology at birth may provide insight into the mechanisms linking adverse in utero events with long-term adult disease since, for example, a male tendency to an inflammatory pathology at the maternal-fetal interface may be linked to the excess risk of coronary artery disease.


Assuntos
Doenças Placentárias/patologia , Placenta/patologia , Nascimento Prematuro/patologia , Fatores Sexuais , Adolescente , Adulto , Decídua/irrigação sanguínea , Decídua/patologia , Feminino , Retardo do Crescimento Fetal/patologia , Idade Gestacional , Humanos , Masculino , Pré-Eclâmpsia/patologia , Gravidez , Estudos Retrospectivos , Cordão Umbilical/patologia
13.
Placenta ; 33(4): 285-93, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22264586

RESUMO

The placental microvasculature is essential for efficient transfer of gases, nutrients and waste between the mother and fetus. Microvascular hypoplasia of the terminal villi is a common pathology in severe Intra Uterine Growth Restriction (IUGR). We used novel methods to obtain placental micro-vascular endothelial cells (PlMEC) from preterm control placentas (n = 3) and placentas from pregnancies with severe IUGR (n = 6) with absent or reversed end-diastolic velocity in the umbilical artery. Distal placental villous tissue was collected to enrich for intermediate and terminal villi. Tissue was digested and PlMEC positively selected using tocosylated magnetic Dynabeads labeled with Human Endothelial Antigen lectin. The purity of the PlMEC (94 ± 2 SD %) was assessed by CD31 and vimentin immunocytochemistry. RNA was extracted from the PlMEC samples and subjected to Affymetrix microarray analysis (U133Plus2 array chips). Comparison of preterm and IUGR PlMEC gene expression profiles identified BTNL9 and NTRK2 transcripts to be upregulated and SAA1 and SLAMF1 transcripts to be downregulated in all 6 IUGR cases relative to preterm controls. A third downregulated gene GNAS was identified to be near significance. Changes were demonstrated to be significant at the mRNA level by Real Time PCR in the PlMEC samples. Changes in the IUGR endothelium were confirmed at the protein level by immunohistochemistry for the 3 with available antibodies. We used a tissue microarray constructed from an independent cohort of placental samples from severe IUGR (n = 7), preeclamptic (n = 7), preterm control (n = 6) and term control (n = 6) pregnancies. Results confirmed differential endothelial expression of BTNL9, NTRK2 and SLAMF1 in IUGR versus preterm and term samples. These studies are the first to characterize PlMEC gene expression profiles thus we have advanced our understanding of the molecular basis of placental micro-vascular pathophysiology in fetal growth restriction.


Assuntos
Endotélio Vascular/metabolismo , Retardo do Crescimento Fetal/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Microvasos/metabolismo , Placenta/irrigação sanguínea , Adulto , Antígenos CD/genética , Antígenos CD/metabolismo , Butirofilinas , Estudos de Coortes , Endotélio Vascular/patologia , Feminino , Retardo do Crescimento Fetal/patologia , Perfilação da Expressão Gênica , Humanos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Microvasos/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Placenta/patologia , Pré-Eclâmpsia/metabolismo , Pré-Eclâmpsia/patologia , Gravidez , Nascimento Prematuro/metabolismo , Nascimento Prematuro/patologia , RNA Mensageiro/metabolismo , Receptor trkB/genética , Receptor trkB/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Proteína Amiloide A Sérica/genética , Proteína Amiloide A Sérica/metabolismo , Índice de Gravidade de Doença , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária , Adulto Jovem
14.
J Thromb Haemost ; 9(12): 2486-97, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21981655

RESUMO

BACKGROUND: Severe preeclampsia is characterized by hypertension, renal injury and placental dysfunction. Prothrombotic disorders are discovered in 10-20% of women with preeclampsia, providing the rationale for prescribing low-molecular-weight heparin (LMWH) in future pregnancies. Heparin has diverse molecular actions and appears to reduce the recurrence risk of preeclampsia in women without prothrombotic disorders. The placenta-derived anti-angiogenic splice-variant protein soluble vascular endothelial growth factor (VEGF) receptor-1 (sFLT1) is strongly implicated in the pathogenesis of the underlying endothelial dysfunction. As the placental syncytiotrophoblast is the principal source of sFLT1, we tested the hypothesis that heparin suppresses placental sFLT1 secretion. METHODS AND RESULTS: First trimester placental villi exposed to LMWH (0.25-25 IU mL(-1)) in an in vitro explant model significantly increased the expression and release of sFLT1 by the syncytiotrophoblast into culture media, reducing phosphorylation of FLT1 and KDR receptors in cultured human umbilical vein endothelial cells. This response was significantly diminished in placental villi from healthy term pregnancies. Placental villi from severely preeclamptic pregnancies had a higher baseline sFLT1 release, compared with first trimester placental villi and did not respond to LMWH treatment. LMWH promoted villous cytotrophoblast proliferation (BrdU incorporation) and impaired syncytial fusion-differentiation, causing syncytiotrophoblast apoptosis (by caspase 3&7 activity and TUNEL staining) and necrosis (ADP/ATP ratio). CONCLUSION: LMWH promotes sFLT1 synthesis and release from first trimester placental villi in a manner similar to that of severely preeclamptic placental villi, which antagonizes VEGF signaling in endothelial cells. These effects in part are mediated by an interaction between heparin and the cytotrophoblasts that regenerates the overlying syncytiotrophoblast responsible for sFLT1 secretion into the maternal blood.


Assuntos
Vilosidades Coriônicas/efeitos dos fármacos , Endotélio Vascular/metabolismo , Heparina de Baixo Peso Molecular/farmacologia , Transdução de Sinais/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Adulto , Sequência de Bases , Vilosidades Coriônicas/metabolismo , Primers do DNA , Feminino , Humanos , Fosforilação , Gravidez , Reação em Cadeia da Polimerase em Tempo Real
15.
J Thromb Haemost ; 9(8): 1483-92, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21689371

RESUMO

OBJECTIVE: To conduct a pilot randomized controlled trial of unfractionated heparin (UFH) in women considered at high risk of placental insufficiency in the second trimester. METHODS: Women with either false-positive first trimester (pregnancy-associated placental protein-A [PAPP-A] < 0.35 MoM) or second trimester (alpha-fetoprotein [AFP] > 2.0 MoM, inhibin > 3.0 MoM, human chorionic gonadotropin > 4.0 MoM) serum screening tests or medical/obstetric risk factors were screened for placental insufficiency by sonographic evaluation of the placenta and uterine artery Doppler between 18 and 22 weeks. Thrombophilia screen-negative women with two or three abnormal test categories were randomized by 23+6 weeks to self-administration of subcutaneous unfractionated heparin (UFH) 7500 IU twice daily until birth or 34 weeks, or to standard care. Maternal anxiety and other maternal-infant outcomes were determined. RESULTS: Thirty-two out of 41 eligible women consented, with 16 women randomized to UFH and 16 to standard care. There was no statistically significant difference identified between the two treatment groups (standard care vs. UFH) for the following: maternal anxiety score (mean [standard deviation]), 14.2 [± 1.6] vs. 14.0 [± 1.8]; birth weight (median [range]), 1795 [470-3295]g vs. 1860 [730-3050]g; perinatal death, 3 vs. 0; severe preeclampsia, 2 vs. 6; placental weight < 10th percentile, 7 vs. 4; or placental infarction, 4 vs. 3. CONCLUSION: Our study design identified women at high risk of adverse maternal-infant outcomes attributable to placental insufficiency. Women with evidence of placental insufficiency were willing to undergo randomization and self-administration of UFH without increased maternal anxiety.


Assuntos
Anticoagulantes/administração & dosagem , Heparina/administração & dosagem , Insuficiência Placentária/tratamento farmacológico , Adulto , Ansiedade/etiologia , Estudos de Viabilidade , Feminino , Humanos , Injeções Subcutâneas , Pessoa de Meia-Idade , Ontário , Projetos Piloto , Insuficiência Placentária/diagnóstico por imagem , Gravidez , Resultado da Gravidez , Segundo Trimestre da Gravidez , Autoadministração/psicologia , Resultado do Tratamento , Ultrassonografia Doppler , Ultrassonografia Pré-Natal
16.
Placenta ; 32(6): 413-9, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21497901

RESUMO

Preeclampsia remains a leading cause of maternal and fetal morbidity and mortality and has an unknown etiology. The limited progress made regarding new treatments to reduce the incidence and severity of preeclampsia has been attributed to the difficulties faced in the development of suitable animal models for the mechanistic research of this disease. In addition, animal models need hypotheses on which to be based and the slow development of testable hypotheses has also contributed to this poor progress. The past decade has seen significant advances in our understanding of preeclampsia and the development of viable reproducible animal models has contributed significantly to these advances. Although many of these models have features of preeclampsia, they are still poor overall models of the human disease and limited due to lack of reproducibility and because they do not include the complete spectrum of pathophysiological changes associated with preeclampsia. This review aims to provide a succinct and comprehensive assessment of current animal models of preeclampsia, their uses and limitations with particular attention paid to the best validated and most comprehensive models, in addition to those models which have been utilized to investigate potential therapeutic interventions for the treatment or prevention of preeclampsia.


Assuntos
Modelos Animais de Doenças , Pré-Eclâmpsia , Animais , Feminino , Humanos , Gravidez
17.
Placenta ; 31(12): 1111-5, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21035847

RESUMO

OBJECTIVE: The sonographic appearance of the placenta is normally homogenous throughout the second trimester. A variety of abnormalities in placental texture have been described, some of which may be pathologic and associated with adverse clinical outcomes. We characterized the pathologic basis of one lesion termed echogenic cystic lesions (ECLs) that may be a prognostic marker in intrauterine growth restriction (IUGR). STUDY DESIGN: We retrospectively correlated placental pathology in 50 pregnancies that had a total of 84 ECLs documented by ultrasound prior to delivery. Six additional women with placental ECLs prospectively underwent immediate post-delivery ultrasound-guided wire localization of 9 lesions followed by placental pathology. Obstetric outcome data were recorded. RESULTS: Severe pre-eclampsia (20%) and extreme IUGR (18%) were common outcomes. Of 93 ECLs identified, 46 (49%) gross lesions were found by placental pathology. Inter-villous thrombosis was the most significant lesion found (30/46, 65%) compared to all other lesions (35%; Z-Test, p = 0.007). Ultrasound guidance identified 8/9 (89%) lesions of which 6/8 (67%) were inter-villous thrombosis. Associated lesions (infarction, 36%; advanced villous maturation, 27%) and small placental weight (<10th centile, 38%) were present in 50%, but did not increase the risk of adverse perinatal outcome. CONCLUSIONS: ECLs are most commonly due to inter-villous thrombosis. The adverse clinical outcomes may be mediated by associated lesions not readily detectable by ultrasound. Ultrasound-guided wire localization is a promising research tool for future large-scale cohort studies needed to define the clinical utility of placental ultrasound findings.


Assuntos
Placenta/diagnóstico por imagem , Trombose/diagnóstico por imagem , Adolescente , Adulto , Cistos/diagnóstico por imagem , Cistos/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Placenta/patologia , Gravidez , Estudos Retrospectivos , Trombose/patologia , Ultrassonografia Pré-Natal , Adulto Jovem
18.
Placenta ; 31(6): 499-505, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20447686

RESUMO

Massive perivillous fibrin deposition (MPFD) and maternal floor infarction (MFI) of the placenta are rare related conditions associated with poor perinatal outcome including antepartum stillbirth. The diseases are characterized by pathologic accumulation of fibrinoid deposits that surround the placental villi (in the case of MFI predominantly in the basal regions adjacent to the decidual plate). These findings suggest either overproduction and/or defective clearance of fibrinoid within the intervillous space. Recently genetic polymorphisms of the plasminogen activator inhibitor-1 (PAI-1) gene have been found in association with impaired fibrinolysis in the pelvis predisposing to endometriosis. We hypothesized that polymorphisms in one or more of four genes that regulate fibrinolysis were associated with MPFD and MFI placentas. We retrospectively identified 20 consecutive cases of MPFD/MFI from our placental pathology database and generated 2 random gestational age-matched controls for each case. Clinical charts were reviewed. DNA was extracted from archived paraffin blocks of placental tissue from cases and controls. Single nucleotide repeat polymorphisms (SNPs) in loci within PAI-1 gene, thrombin activated fibrinolysis inhibitor (TAFI) gene, plasminogen activator urokinase (u-PA) gene and plasminogen activator tissue (t-PA) gene were studied using PCR methods. Outcomes in the study group included perinatal death (8), preterm IUGR (6), preeclampsia (4) and only 3 normal term deliveries. A spectrum of placental ultrasound abnormalities was observed. No SNP polymorphism was found to associate with MPFD/MFI. MPFD/MFI are associated with significant abnormal perinatal outcomes but have not been shown to be mediated by polymorphisms in candidate genes that are predicted to impair fibrinolysis in our study.


Assuntos
Vilosidades Coriônicas/patologia , Fibrina/genética , Doenças Placentárias/genética , Carboxipeptidase B2/genética , Estudos de Casos e Controles , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Doenças Placentárias/patologia , Inibidor 1 de Ativador de Plasminogênio/genética , Polimorfismo de Nucleotídeo Único , Gravidez , Resultado da Gravidez , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ativador de Plasminogênio Tecidual/genética , Ativador de Plasminogênio Tipo Uroquinase/genética
19.
Can J Cardiol ; 26(1): e1-6, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20101358

RESUMO

OBJECTIVES: To assess outcomes of prenatally diagnosed tetralogy of Fallot and determine factors associated with the choice to undergo a valvesparing repair versus transannular patch, and the use of prostaglandins at birth. METHODS: All cases at The Hospital for Sick Children (Toronto, Ontario) with a fetal diagnosis of tetralogy of Fallot from 1998 to 2006, were reviewed for demographic and fetal echocardiographic data to determine factors associated with the valve-sparing repair and need for perinatal support. RESULTS: Sixty-four fetuses met inclusion criteria (median gestational age 22 weeks) with 47 live births. Twenty-six underwent valve-sparing repair (median age 5.7 months) and 14 underwent transannular patch repair (median age 4.5 months). There were seven deaths before surgery and one post-transannular patch repair. One patient required a transannular patch repair after the initial valve-sparing repair. Twelve of 29 (41%) patients received prostaglandins at birth. Type of surgical repair, use of prostaglandins and postnatal death were among the outcomes investigated. The mean pulmonary valve (PV) z-score was -3.0+/-2.0 and the mean PV/aortic valve (AoV) ratio was 0.65+/-0.10. Lower PV z-score (P=0.04), smaller PV/AoV ratio (P=0.04) and the presence of nonantegrade arterial duct flow (P=0.02) were associated with prostaglandin use. A higher PV/AoV ratio was associated with valvesparing repair (P=0.04). Fetal z-scores of the PV, AoV and right pulmonary artery at 29 to 32 weeks gestational age correlated with respective postnatal z-scores (P=0.01). CONCLUSION: Fetal echocardiographic variables were associated with the use of prostaglandins and valve-sparing repair in fetuses with tetralogy of Fallot, and at 29 weeks, correlated with postnatal valve diameters.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Avaliação de Resultados em Cuidados de Saúde , Valva Pulmonar/cirurgia , Tetralogia de Fallot/cirurgia , Anormalidades Múltiplas/mortalidade , Valva Aórtica/diagnóstico por imagem , Peso ao Nascer , Aberrações Cromossômicas , Feminino , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Masculino , Gravidez , Diagnóstico Pré-Natal , Prostaglandinas Sintéticas/uso terapêutico , Artéria Pulmonar/diagnóstico por imagem , Valva Pulmonar/diagnóstico por imagem , Insuficiência da Valva Pulmonar/prevenção & controle , Análise de Sobrevida , Tetralogia de Fallot/diagnóstico , Tetralogia de Fallot/mortalidade , Ultrassonografia , Obstrução do Fluxo Ventricular Externo/cirurgia
20.
Ultrasound Obstet Gynecol ; 34(3): 274-82, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19672838

RESUMO

OBJECTIVES: Screening studies for trisomy 21 demonstrate that low maternal serum pregnancy-associated plasma protein-A (PAPP-A) at 11-13 weeks' gestation is associated with stillbirth, intrauterine growth restriction (IUGR) and pre-eclampsia in chromosomally normal fetuses. However, the strength of these associations is too weak to justify screening for these placental insufficiency syndromes. Our objective was to evaluate placental size and uterine artery (UtA) Doppler imaging as second-stage screening tests for women with low PAPP-A. METHODS: We prospectively studied 90 normal singleton pregnancies with first-trimester PAPP-A

Assuntos
Retardo do Crescimento Fetal/diagnóstico , Placenta/diagnóstico por imagem , Insuficiência Placentária/diagnóstico por imagem , Proteína Plasmática A Associada à Gravidez/análise , Artéria Uterina/diagnóstico por imagem , Adulto , Biomarcadores/sangue , Feminino , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Tamanho do Órgão , Placenta/anatomia & histologia , Gravidez , Resultado da Gravidez , Nascimento Prematuro , Fatores de Risco , Natimorto , Ultrassonografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA