Conservative management of placenta previa complicated by abnormal placentation

Abstract

Objective: Abnormal implantation of placenta previa is life-threatening condition. The purpose of this study was to evaluate the impact of the conservative management of pregnancies with such complication on maternal morbidity rate and the chance for uterine preservation (fertility).

Methods: Eleven patients with abnormal implantation of placenta previa were analyzed prospectively. This complication was diagnosed antenatally by two-dimensional ultrasound and color flow Doppler. The following outcomes were analyzed: need for blood transfusion, admission and duration of stay in intensive care unit, infections, coagulopathies, time between cesarean section and delivery of placenta, hysterectomy and preservation of uterus.

Results: Among the 20 085 women who had a singleton gestation, 11 (0.054%) were identified with placenta previa with abnormal placentation. In five patients (group A), hysterectomy was performed because of hemorrhage or placenta ablation. In six patients (group B), conservative management succeeded and placenta were preserved. In group A, placenta were delivered earlier (2?d–8 weeks) in comparison with group B (6–15 weeks). Estimated blood loss during the delayed delivery of placenta was higher in the group with hysterectomy (respectively, 450–1600 and 300–500?ml).

Conclusions: Conservative management of placenta previa with abnormal implantation decreases the risk of severe hemorrhage at the time of delivery and can preserve fertility.     

妊娠高血压综合征患者胎盘肝细胞生长因子的表达与胎盘血管发生

目的　探讨肝细胞生长因子 (hepatocytegrowthfactor,HGF)在正常妊娠妇女胎盘和妊高征患者胎盘组织中的表达及对妊高征胎盘绒毛血管发生的影响。　方法　不同程度妊高征晚孕和正常妊娠晚孕孕妇共 78例 ,采用免疫组织化学SP法检测胎盘组织HGF的表达强度 ,同时作HE染色 ,选取5个高倍视野 ,计数绒毛血管数。　结果　HGF主要表达于绒毛间质细胞胞浆 ,蜕膜细胞有少量表达。重度妊高征患者胎盘绒毛间质细胞HGF表达强度 ( )为 1例 ,显著低于正常晚孕组的表达强度( )为 4例 (H =7.395 ,P =0 0 0 3) ,而轻度及中度妊高征组HGF表达强度 ( )均为 2例与正常晚孕组比较 ,差异无显著性 (H =0 .86 9,P =0 .35 1,H =0 .0 17,P =0 .896 )。不同程度妊高征胎盘绒毛血管密度均较正常孕妇减少 ,重度妊高征组绒毛血管密度为 (5 7.5 1± 15 .4 9)个 / 4 0 0×与正常晚孕组(6 7.91± 16 .90 )个 / 4 0 0×相比 ,差异有显著性 (F =10 .6 76 ,P =0 .0 0 8)。相关分析显示 ,胎盘间质细胞HGF表达强度与绒毛血管密度呈正相关 (r =2 2 4 6 ,P =0 0 30 )。　结论　HGF在胎盘中主要由绒毛间质细胞分泌 ,妊高征患者HGF分泌减少可能是引起胎盘血管网减少的原因之一。     

子痫前期患者胎盘组织中血小板源性生长因子A的表达及意义

目的 探讨子痫前期患者胎盘组织中血小板源性生长因子A(PDGF-A)的表达变化及其临床意义.方法 应用免疫组化链霉菌抗生物素蛋白-过氧化物酶连接(SP)法,检测38例子痫前期患者(子痫前期组,其中轻度子痫前期18例、重度子痫前期20例)及22例正常妊娠晚期妇女(正常妊娠组)胎盘组织中PDGF-A的表达.结果 (1)PDGF-A的表达部位:PDGF-A主要在胎盘滋养细胞和毛细血管内皮细胞的胞膜及胞质中表达.(2)胎盘滋养细胞PDGF-A的表达:子痫前期组胎盘滋养细胞PDGF-A的阳性表达率为63%(24/38),正常妊娠组为32%(7/22),两组比较,差异有统计学意义(P＜0.05).(3)毛细血管内皮细胞PDGF-A的表达:子痫前期组毛细血管内皮细胞PDGF-A的阳性表达率为68%(26/38),正常妊娠组为27%(6/22),两组比较,差异有统计学意义(P＜0.01).(4)不同程度子痫前期患者PDGF-A的表达:轻度子痫前期患者胎盘滋养细胞PDGF-A的阳性表达率为39%(7/18),重度子痫前期患者胎盘滋养细胞PDGF-A的阳性率为85%(17/20),两者比较,差异有统计学意义(P＜0.01).结论 子痫前期患者胎盘滋养细胞和毛细血管内皮细胞PDGF-A的高表达,可能与子痫前期发生、发展有关.     

Abnormal placentation: evidence-based diagnosis and management of placenta previa, placenta accreta, and vasa previa

Placenta previa, placenta accreta, and vasa previa cause significant maternal and perinatal morbidity and mortality. With the increasing incidence of both cesarean delivery and pregnancies using assisted reproductive technology, these 3 conditions are becoming more common. Advances in grayscale and Doppler ultrasound have facilitated prenatal diagnosis of abnormal placentation to allow the development of multidisciplinary management plans to achieve the best outcomes for mother and baby. We present a comprehensive review of the literature on abnormal placentation including an evidencebased approach to diagnosis and management.     

妊娠高血压综合征患者胎盘组织中肝细胞生长因子及其受体的表达

目的探讨肝细胞生长因子(hepatocyte growth factor，HGF)及其受体(c-met)在正常妊娠妇女及妊高征患者胎盘组织中的表达及对妊高征胎盘滋养细胞功能的影响。方法不同程度妊高征晚孕和正常妊娠晚孕孕妇共78例，采用免疫组织化学SP法检测胎盘组织HGF及c-met的表达强度。结果HGF主要表达于绒毛间质细胞胞浆。重度妊高征组胎盘绒毛间质细胞HGF表达强度显著低于正常晚孕组(H=7．395，P=0．007)，而轻度及中度妊高征组与正常晚孕组比较，差异无显著性(H=0．869，P=0．351；H=0．017。P=0．817)。c-met主要表达于滋养细胞。重度妊高征患者胎盘绒毛滋养细胞c-met表达强度显著低于正常晚孕组(H=4．577，P=0．032)，而轻度及中度妊高征组与正常晚孕组比较，差异无显著性(H=0．178，P=0．673；H=0．824，P=0．364)。HGF与c-met表达强度呈负相关(phi关联系数：7．809，P=0．005)。结论HGF在胎盘中主要由绒毛间质细胞分泌，其受体c-met表达于滋养细胞表面，妊高征患者HGF分泌减少可能是引起其胎盘出现生理性血管重铸障碍继而发病的原因。     

Angiogenic growth factor expression in placenta

New blood vessel growth is generally a rare event in the healthy adult. However, a notable exception to this is the female reproductive tract where cyclic angiogenesis occurs. Striking new vessel growth and remodeling also occurs during placentation; thus angiogenesis is essential for reproductive success. Vascular endothelial growth factor is a potent stimulator of this process and its production and action is tightly regulated. Indeed the placenta is a rich source of a soluble variant of the flt-1 receptor which seems to protect the placenta from the effects of excess vascular endothelial growth factor. The balance between new vessel growth (in the placental villi for example) and endothelial cell loss in the spiral arteries within the decidua is a delicate one. This is influenced by the local production of promotors and inhibitors of endothelial cell activation. Perturbation of this may lead to maternal pathology during pregnancy.     

脐动脉波形异常伴胎儿宫内生长迟缓患者胎盘血管内皮生？…

目的 探讨胎儿脐动脉波形异常伴宫内生长迟缓（ＩＵＧＲ）与胎盘血管内皮生长因子（ＶＥＧＦ）表达水平的关系,并得出胎盘的氧水平。方法 应用彩色多谱勒超声,对４０例妊娠晚期妇女进行胎儿脐动脉搏动指数（ＰＩ）、阻力指数（ＲＩ）及收缩期末最大血流速度与舒张期末最小血流速度比值（Ｓ／Ｄ）测定,根据脐动脉波形变化分为４个组。脐动脉波形异常伴ＩＵＧＲ组（ＡＶＡＷ组）、脐动脉波形异常不伴ＩＵＧＲ组（ＡＶＮＷ组）、脐     

Expression of epidermal growth factor receptor and c-erbB-2 oncoprotein in trophoblast populations of placenta accreta

OBJECTIVE: The purpose of this study was to investigate the expression of epidermal growth factor receptor and c-erbB-2 oncoprotein in trophoblast populations of placenta accreta. STUDY DESIGN: Paraffin sections of 43 placental specimens with (cases) and 43 without (controls) placenta accreta were studied immunohistochemically for epidermal growth factor receptor and c-erbB-2 expression in the syncytiotrophoblast, villous cytotrophoblast, and extravillous cytotrophoblast. Epidermal growth factor receptor and c-erbB-2 protein levels were also performed by Western blot analysis. Controls were matched for gestational age in this case-control study. RESULTS: The percentage of strong/intermediate immunoreactivity of epidermal growth factor receptor in the syncytiotrophoblast was significantly higher in cases (98%) than controls (79%; odds ratio,11.1; 95% CI, 1.3-92.0; P = .03), although strong/intermediate immunoreactivity of c-erbB-2 in the syncytiotrophoblast was significantly lower in cases (35%) than controls (81%; odds ratio, 0.1; 95% CI, 0.1-0.3; P < .001). Epidermal growth factor receptor and c-erbB-2 expression in the villous and extravillous cytotrophoblastic cells were not significantly different between controls and cases ( P > .05). Most immunoreactive bands on Western blots were consistent with the trends of immunohistochemical findings. CONCLUSION: The development of placenta accreta is related closely to the differential expression of epidermal growth factor receptor and c-erbB-2 in the syncytiotrophoblast.     

妊娠高血压综合征患者胎盘组织中血管内皮生长因子的表达

目的　探讨血管内皮生长因子（VEGF）在妊娠高血压综合征（妊高征）患者胎盘组织中的表达及对妊高征患者胎盘滋养细胞功能和绒毛毛细血管网形成的影响。方法　采用免疫组织化学SP法检测21例正常孕妇（对照组）,60例妊高征患者（妊高征组,其中轻、中、重度妊高征患者各20例）胎盘组织VEGF的表达强度。结果　VEGF主要表达于胎盘绒毛滋养细胞;中度及重度妊高征患者胎盘绒毛滋养细胞VEGF表达强度均明显低于对照组及轻度妊高征患者(P＜0.05),而轻度妊高征患者与对照组比较,差异无显著性(P＞0.05),各组间蜕膜组织VEGF表达强度差异无显著性(P＞0.05)。　结论　VEGF在胎盘中主要由绒毛滋养细胞分泌,妊高征患者VEGF分泌减少,可能是引起局部胎盘绒毛及血管病变的原因之一。     

子痫前期患者胎盘合体滋养细胞中Fas抗原及其配体、胎盘生长因子表达的研究

目的　探讨Fas抗原(Fas)及其配体(FasL)、胎盘生长因子(PlGF)在子痫前期患者胎盘合体滋养细胞中的表达变化及其意义。方法　采用免疫组化链霉菌抗生物素蛋白过氧化物酶(SP)连接法检测24例正常晚期妊娠妇女(正常晚孕组)、24例轻度子痫前期产妇(轻度子痫前期组)及24例重度子痫前期产妇(重度子痫前期组)胎盘组织中Fas、FasL及PlGF表达水平。结果Fas、FasL及PlGF主要表达于胎盘合体滋养细胞胞质及胞膜中。FasL、PlGF在轻度子痫前期组(63±4、81±6)及重度子痫前期组(42±6、65±6)胎盘中的表达均低于正常晚孕组(73±9、88±8),分别与正常晚孕组比较,差异均有统计学意义(P<0. 01)。Fas在轻度子痫前期组(51±4)及重度子痫前期组(67±6)胎盘中的表达均高于正常晚孕组(43±6),分别与正常晚孕组比较,差异均有统计学意义(P<0. 01)。结论　Fas、FasL及PlGF在子痫前期胎盘合体滋养细胞中表达失衡,可能与子痫前期的发病及发展有关。     

缺氧诱导因子1α及其靶基因在子痫前期患者胎盘组织中的表达

目的探讨缺氧诱导因子1α(HIF-1α)及其靶基因血管内皮细胞生长因子(VEGF)、可溶性血管内皮细胞生长因子受体1(sFlt-1)基因在子痫前期患者胎盘组织中的表达。方法采用免疫组化链霉菌抗生物素蛋白-过氧化物酶连接(SP)法对20例重度子痫前期患者(子痫前期组)和15例正常妊娠妇女(对照组)的胎盘组织中的HIF-1α、VEGF、sFlt-1蛋白表达进行检测;同时应用RT- PCR技术对两组孕妇胎盘组织中HIF-1α、VEGF、sFlt-1 mRNA水平进行检测,并进行相关性分析。结果(1)子痫前期组HIF-1α蛋白表达(+++)者9例(45%,9/20),sFlt-1蛋白表达(+++)者11例(55%,11/20),对照组分别为2例(13%,2/15)和3例(20%,3/15),两组分别比较,差异均有统计学意义(P＜0．05);子痫前期组VEGF蛋白表达(+++)者3例(15%,3/20),明显低于对照组的7例(47%,7/15),两组比较,差异有统计学意义(P＜0．01)。(2)子痫前期组HIF-1αmRNA、sFlt-1 mRNA水平分别为0．604±0．013、0．898±0．041,对照组分别为0．208±0．007、0．559±0．244,两组分别比较,差异均有统计学意义(P＜0．05);子痫前期组VEGF mRNA表达水平虽高于对照组,但差异无统计学意义(P＞0．05)。子痫前期组VEGF mRNA/sFlt-1 mRNA比值(0．439±0．009)低于对照组(0．824±0．011),两组比较,差异有统计学意义(P＜0．05)。(3)子痫前期组HIF-1αmRNA的表达与sFlt-1 mRNA表达呈正相关(r=0．577,P＜0．05),与VEGF mRNA/sFlt-1 mRNA比值呈负相关(r= -0．376,P＜0．05)。结论HIF-1α在子痫前期患者胎盘组织中表达水平明显升高,主要是通过调节VEGF、sFlt-1基因的转录,而影响滋养细胞的浸润和胎盘血管重铸,参与子痫前期的发病。     

Vascular endothelial growth factor, placenta growth factor and their receptors in isolated human trophoblast

The expression of the angiogenic growth factors, vascular endothelial cell growth factor (VEGF) and placenta growth factor (PIGF) was demonstrated in isolated human term cytotrophoblast and in vitro differentiated syncytiotrophoblast. RNase protection assays demonstrated VEGF expression in both cytotrophoblast and syncytiotrophoblast while prominent PIGF expression was detected in both types of trophoblast by Northern blot analyses. VEGF expression increased approximately eightfold in trophoblast cultured under hypoxic conditions (1 per cent O₂) yet PIGF expression decreased 73 ± 5.5 per cent in the same trophoblast. These results suggest distinct regulatory mechanisms govern expression of VEGF and PIGF in trophoblast. Characterization of the VEGF/PIGF receptors, KDR and flt-1, revealed the presence of flt-1 mRNA in isolated cytotrophoblast and in vitro differentiated syncytiotrophoblast. KDR was not detected in the isolated trophoblast. Exogenous rhVEGF induced c-Jun N-terminal kinase (JNK) activity in the normal trophoblast indicating that the flt-1 receptors on trophoblast are functional. Trophoblast-derived VEGF/PIGF could act in a paracrine fashion to promote uterine angiogenesis and vascular permeability within the placental bed. In addition, presence of functional flt-1 on normal trophoblast suggests that VEGF/P1GF functions in an autocrine manner to perform an as yet undefined role in trophoblast invasion, differentiation, and/or metabolic activity during placentation.     

The expression of insulin-like growth factor and insulin-like growth factor binding protein mRNAs in mouse placenta

Insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) are paracrine regulators of tissue growth and development, and are expressed at the sites of biological action. To study the role of the IGFs and IGFBPs in mouse placental development, we determined the temporal and spatial expression patterns of the mRNAs at embryonic days 10.5 to 18.5 by in situ hybridization. IGF-II mRNA was expressed strongly in mesoderm and fetal blood vessels of early placenta and in labyrinthine trophoblast of later placenta. In the junctional zone, IGF-II mRNA was expressed first in spongiotrophoblasts, later strongly in glycogen cells and variably in giant cells. IGFBP-2 mRNA was expressed weakly in spongiotrophoblasts and glycogen cells. IGFBP-2, -5 and -6 mRNAs were detected in the stroma of the metrial gland. Myometrium expressed IGFBP-2 mRNA strongly, IGFBP-6 mRNA moderately and IGFBP-5 mRNA weakly. The endothelium of maternal blood vessels in decidua expressed IGFBP-3 and -5 mRNAs, and some deeper vessels expressed IGFBP-4 mRNA. In the yolk sac, IGF-II mRNA was expressed in endoderm and mesoderm, whereas IGFBP-1, -2 and -4 mRNAs were expressed only in endoderm, and IGFBP-4 mRNA in mesoderm. Strong expression of IGF-II mRNA in glycogen cells suggests a role in the autocrine/paracrine regulation of invasion. Similar to rat and guinea pig, but in contrast to man and primates, IGFBP mRNAs, except IGFBP-4, were not expressed in mouse decidua. However, IGFBP-3, -4 and -5 mRNAs were expressed in endothelium of maternal blood vessels, and IGFBP-2 and -6 mRNAs in myometrium, where IGFBPs may play a critical role in regulating trophoblast invasion. These findings suggest possible biological roles of the peptides at the feto-maternal interface.     

Plasma placenta growth factor levels in midtrimester pregnancies

OBJECTIVE: Previous studies have shown decreased levels of placenta growth factor in serum of pregnant women with preeclampsia. The aim of this study was to investigate whether levels of placenta growth factor are decreased before the clinical onset of preeclampsia, and whether placenta growth factor levels are decreased in pregnancies complicated by intrauterine growth restriction. METHODS: From an ongoing longitudinal study, 101 plasma samples were collected from 72 pregnant women at weeks 11-21 of gestation. Placenta growth factor levels were determined retrospectively in plasma using an enzyme-linked immunosorbent assay. Correlations between plasma concentrations of placenta growth factor and pregnancy outcome were evaluated. RESULTS: Plasma samples of 72 patients were analyzed. Forty-four patients had no pregnancy complications, 18 developed preeclampsia, and 10 women had pregnancies complicated by intrauterine growth restriction. Between week 17 and week 21 of pregnancy, a significantly lower level of placenta growth factor was found in plasma of patients who later developed preeclampsia (n = 10), compared with control pregnancies (n = 25, P = .004). In women with a growth-restricted baby at birth (n = 5), levels of placenta growth factor were also low. CONCLUSIONS: Our results show that plasma placenta growth factor levels are decreased before preeclampsia is clinically evident. The data suggest that placenta growth factor may be useful to determine the relative risk of developing preeclampsia and intrauterine growth restriction.     

HIF-1α、VEGF及MVD在子痫前期不同发病类型胎盘的表达

目的:探讨缺氧诱导因子1α(HIF-1α)、靶基因血管内皮生长因子(VEGF)及微血管密度(MVD)在子痫前期患者胎盘组织的表达及与胎盘血管病变的关系。方法:用链酶菌抗生物素蛋白-过氧化物酶连接(SP)法检测早发型,晚发型重度子痫前期患者和正常妊娠妇女(对照组)胎盘组织中HIF-1α、VEGF的表达,并计数胎盘微血管密度(MVD)值,并进行相关性分析。结果:(1)子痫前期患者胎盘组织中HIF-1α阳性表达率明显高于正常对照组,差异有统计学意义(P<0.05),早发型、晚发型子痫前期组HIF-1α与正常对照组的差异有统计学意义(P<0.05),早发型组HIF-1α阳性表达率高于晚发型组,两者差异有统计学意义(P<0.05);(2)子痫前期患者胎盘组织中VEGF阳性表达率低于正常对照组,两者差异有统计学意义(P<0.05),而早发型组VEGF阳性表达率低于晚发型组,差异亦有统计学意义(P<0.05);(3)正常对照组,晚发型子痫前期组,早发型子痫前期组MVD计数依次递减,子痫前期组与正常对照组比较有统计学差异(P<0.05),早发型组与晚发型组比较有统计学差异(P<0.05);(4)子痫前期组和正常对照组胎盘中HIF-1α表达与VEGF及MVD值的变化呈显著负相关(r=-0.562,P<0.05;r=-0.622,P<0.05),VEGF及MVD值的变化则呈显著正相关(r=0.718,P<0.05)。结论:HIF-1α在子痫前期患者胎盘组织中表达升高,通过下调靶基因VEGF,引起VEGF降低,影响胎盘血管重铸,参与子痫前期的发生和发展。     

Levels of placenta growth factor in gestational trophoblastic diseases

OBJECTIVE: The aim of the current study was to investigate levels of placenta growth factor in the tissues and sera of the patients with gestational trophoblastic disease and to determine its usefulness for the treatment of gestational trophoblastic disease. STUDY DESIGN: Placenta growth factor concentrations were measured in the tissue homogenates of 12 normal placentas, 33 complete hydatidiform moles, and 6 gestational choriocarcinomas. Serum placenta growth factor levels were determined in 59 women with normal pregnant course, in 30 women with complete hydatidiform mole, in 36 women with persistent gestational trophoblastic disease, and 100 nonpregnant healthy volunteers. RESULTS: Serum and tissue placenta growth factor levels in the patients with mole tended to be decreased compared with the levels in normal pregnancy; the levels were increased significantly in patients with choriocarcinoma. When serum placenta growth factor levels were >20 pg/mL (normal upper limit in nonpregnant women), placenta growth factor-to-human chorionic gonadotropin ratios were increased significantly in patients with persistent gestational trophoblastic disease. CONCLUSION: Serum placenta growth factor levels are not of any predictive value in patients with hydatidiform mole. However, elevated serum placenta growth factor levels with increased placenta growth factor-to-human chorionic gonadotropin ratios are suggestive of persistent gestational trophoblastic disease.     

Expression of receptors for tumor necrosis factor in human placenta at term.

The biological effects of tumor necrosis factor (TNF) are mediated through its interaction with high affinity receptors on target cells. Secretion of soluble cytokine receptors has been suggested as a mechanism of regulating cytokine activity in vivo. In a previous study we detected soluble TNF receptors (TNFRs) in amniotic fluid and urine samples from pregnant women, suggesting that secretion of soluble TNFRs may provide a mechanism for protection of the fetus against TNF action during pregnancy. In the present study, TNFR containing cells in cryostat sections from normal placentas at term were evaluated by monoclonal antibodies against the 55 kD--and the 75 kD TNFR in an indirect immunofluorescence technique. The 55 kD TNFR was expressed by the villous syncytiotrophoblasts, by vascular endothelial cells, by some decidual cells and by occasional cells in the placental stroma. Staining for the 75 kD TNFR was confined to the vascular endothelial cells, a relatively small number of stromal cells and decidual cells, whereas the villous syncytiotrophoblasts were negative. The abundant expression of TNFRs in placental tissue suggests: 1. That a considerable number of the placental cells are receptive to the regulatory activities of TNF; 2. That placental cells may be the cellular origin of soluble TNFRs secreted during pregnancy.