孕中期血清AFP、F-βHCG筛查唐氏综合征

目的 探讨孕妇血清标记物甲胎蛋白(AFP)和游离绒毛膜促性腺激素(F-βHCG)对孕中期孕妇进行唐氏综合征为主的先天缺陷筛查的作用。方法 对孕中期(15-20W)妇女进行上述二项血清生化指标检测,经过软件计算风险,对可能影响结果的部分因素,如孕妇年龄、体重、孕周等加以分析校正,对高风险孕妇,建议进一步行羊水或脐血染色体检查及B超进行确诊。结果 3268例孕妇中,发现唐氏综合征3例,神经管畸形2例,死胎4例,其他胎儿异常2例。结论 孕中期血清AFP、F-βHCG二项血清生化指标联合检测,作为筛查胎儿先天缺陷,尤其是胎儿染色体三体、神经管畸形有效可行。筛查结果高危孕妇应进一步行羊水染色体或B超检查确诊,以减少缺陷儿出生。     

神经管缺陷的孕中期筛查

目的通过检测孕妇血清甲胎蛋白(AFP),进行孕中期胎儿神经管缺陷(NTD)的无创伤性产前筛查.方法采用金标定量系统对孕中期 (14～22w)妇女进行AFP检测,并配有神经管缺陷产前筛查专用软件进行分析校正.结果接受筛查的378名孕妇中,神经管畸形高风险孕妇为9例,筛查阳性率为2.38%,经彩超或B超确认7例神经管缺陷,占被筛查人数的1.85%,于28w前终止妊娠.随访追踪每例筛选的孕妇至胎儿出生.结论利用孕妇血清AFP进行孕中期胎儿神经管缺陷无创伤性产前筛查,是降低围产儿死亡率和出生缺陷率重要手段之一.     

孕中期母血清筛查胎儿出生缺陷的研究

目的研究孕妇血清标记物产前筛查胎儿染色体异常及神经管缺陷.方法应用时间分辩免疫荧光法检测1297例孕中期母血清AFP和F-HCG并与B超、羊水、新生儿检查结果对照.结果筛查出高风险孕妇109例,确诊神经管畸形4例,染色体异常3例,无筛查漏检病例发现.结论孕中期二联法作为产前筛查胎儿染色体异常及神经管缺陷有效.     

孕中期母血产前筛查先天缺陷的研究

目的评价孕中期AFP和游离βHCG二联生化指标在产前筛查中的实用价值。方法应用时间分辨荧光免疫检测技术对3384例孕15~20w孕妇外周血AFP和游离βHCG二联生化指标进行检测,检测结果应用Multicalc软件计算出唐氏综合征、神经管畸形、爱得华综合征等三种先天缺陷的风险率,高风险孕妇建议B超、羊水或脐血培养明确诊断,产后随访证实。结果产前筛查3384例孕妇,筛查出高危孕妇177例,阳性率为4.3%,其中唐氏高风险131例,18三体高风险7例,神经管畸形高风险21例。高危孕妇行羊水培养133例,发现异常核型6例。B超证实胎儿畸形10例。结论孕中期生化二联指标是产前筛查异常胎儿的有效指标,遵循产前诊断规定的条件下,值得推广应用。     

孕中期母血清AFP检测产前筛查胎儿神经管缺陷的研究

目的 通过检测孕妇血清甲胎蛋白(AFP),进行孕中期胎儿开放性神经管缺陷(NTD)的无创伤性产前筛查.方法 采用时间分辨荧光免疫分析技术对孕中期(15-20周)孕妇进行血清AFP检测,并应用2T-Risks风险评估软件计算风险率,高危孕妇经彩超确诊.结果 接受筛查的16340例孕妇中,神经管畸形高风险孕妇为135例,筛查阳性率为8.26‰,经彩超确认16例有神经管缺陷或腹壁缺损等畸形,占筛查高危孕妇的11.85%.结论 利用孕妇血清AFP进行孕中期胎儿神经管缺陷产前筛查,是降低围产儿死亡率和出生缺陷率重要手段之一.     

唐氏综合征产前筛查与诊断

目的探讨孕中期母血生化标志物在筛查唐氏综合征胎儿中的作用.方法用酶标定量法对孕14～20w的1580例孕妇血清中β-HCG、AFP进行检测,经过风险计算,对高危孕妇进行羊水细胞遗传学检查或/和B超检查.结果1580例孕妇中唐氏(DS)高危孕妇146例,筛出率9.24%;神经管畸形(NTD)高危孕妇42例,筛出率2.66%.在高危孕妇中4例羊水细胞培养胎儿染色体异常,1例B超诊断为胎儿脑积水.结论孕中期母血生化标志物是筛查胎儿染色体异常和神经管畸形的理想指标.     

6746例孕妇血清生化二联标记物筛查唐氏综合征分析

目的探讨孕妇血清标志物甲胎蛋白(AFP)和游离绒毛膜促性腺激素(Free-βhCG)对孕中期妇女进行胎儿唐氏综合征(Down's syndrome,DS)为主的先天缺陷筛查的作用.方法对孕15w～19w妇女进行上述二项血清标志物检测,结合孕妇年龄、孕周、体重等因素,经过软件计算风险率,对高风险孕妇进行羊水细胞染色体检查及三维彩超进行确诊.结果6746例孕妇中,发现DS 2例,18-三体综合征2例,其它胎儿异常24例.结论孕中期血清AFP、Free-βhCG二项血清标志物联合检测,可作为孕中期唐氏综合征筛查优选项目;在孕中期用AFP、Free-βhCG检测还可以筛查神经管缺陷(NTD),18-三体综合征等其它胎儿异常.     

神经管缺陷的一种确切试验——用交叉亲和免疫电泳检查人羊水α-胎蛋白(AFP)的刀豆素A反应型

对羊水中AFP浓度的测定,一般已作为神经管缺陷或其他严重畸形的一种检查方法,但少数怀有神经管缺陷胎儿的孕妇,羊水中AFP的浓度仅临界水平的升高,而怀正常胎儿孕妇的羊水中,AFP的浓度也有轻度升高的,所以鉴别假阳性和假阴性试验方法的建立,是具有很大临床意义的。 1979年Hindersson等用刀豆素A交叉亲和免疫电泳技术,分析了羊水中AFP的刀豆素A反应型,作者把此法稍加改进,用来研究了25名怀有神经管缺陷或其他伴有AFP浓度升高异常胎儿的孕妇羊水和128名正常孕妇的羊水标本,所有标本均以交叉线形亲     

湖州地区80256例胎儿神经管畸形筛查的结果分析

目的评价胎儿神经管畸形的血清学筛查的意义。方法回顾分析2014~2016年3年内在我院进行中孕唐氏筛查的80 256名孕妇,按血清甲胎蛋白AFP的2.5倍中位数倍数MOM值进行神经管畸形低高危分组,观察所有孕妇的妊娠结局,分析其与神经管畸形高危的相关性。结果 80 256名孕妇中,NTDs高风险孕妇402例,其中胎儿有异常者69例,包括神经管畸形9例,死胎36例,早产和其他异常24例;NTDs低风险孕妇中神经管畸形漏检3例,NTDs检出率为75%。结论对孕妇进行神经管畸形的血清学筛查是减少缺陷儿出生的经济有效的方法。     

应用抗甲胎蛋白单克隆抗体对AFP抗原性的研究

甲胎蛋白(AFP)是胎儿肝脏和卵黄囊合成的一种糖蛋白。在胎儿有神经管缺陷、先天性肾病、死胎等情况下,羊水及母体血清中AFP浓度升高。原发性肝细胞癌和内胚窦瘤患者血清中AFP浓度也升高。测定羊水及/或血清中AFP含量,有助于上述先天性畸形的产前诊断和有关肿瘤的早期发现及其疗效观察。目前利用传统的多克隆抗体(PcAb)的放射免疫分析     

Radioimmunassay of ovine alpha-fetoprotein

Highly purified ovine alpha-fetoprotein (AFP) was used both for radioisotope labelling and as the reference standard in the double antibody radioimmunoassay of ovine AFP. The sensitivity of the assay is 2 ng/ml which is about 8000 times more sensitive than radialimmunodifussion assay. The assay is of sufficient sensitivity to quantitate AFP in normal adult sheep serum, pregnancy serum, amniotic fluid and fetal lamb serum.     

Assessment of AFP in amniotic fluid: comparison of three automated techniques

Ultrasound scanning is useful to detect neural tube defect (NTD) but scarcely distinguished between closed NTD and open NTD, which had very different prognosis. An amniotic fluid punction is thus mandatory to search for an increase in alpha foeto protein (AFP) levels and for the presence of acetylcholinesterase which identified open NTD. However, AFP levels fluctuate both with the gestational age and the assay used. Our aim was to establish normative values for AFP in amniotic fluid in the second half of pregnancy using three different immunoassays and to improve their clinical relevance. Amniotic fluid punctions were performed on 527 patients from 9 week of gestation (WG) to 37 WG either for maternal age, Trisomy 21 screening, increase in nucal translucency (control group, n = 527) or for suspicion of neural tube defect or abdominal defect (n = 5). AFP was measured using the immunoassay developed for serum AFP on the Access 2 system, the Immulite 2000 and the Advia Centaur. Results were expressed in ng/ml, multiple of the median (MoM) and percentiles. AFP decrease by 1.5 fold between 9 and 19 WG. When NTD was suspected, an increase in anmniotic AFP was observed (from 2.5 MoM to 9.3 MoM) confirming an open NTD. In conclusion, the assay developed on those 3 automates is suitable for the measurement of AFP in amniotic fluid.     

Risks associated with an elevated amniotic fluid alpha-fetoprotein level.

Two and two-tenths percent of 85,000 consecutive amniotic fluid (AF) samples had alpha-fetoprotein (AFP) levels greater than or equal to 2.0 MoM. Half measured 2.0-2.4 MoM, and 93% had a normal outcome. Sixty-seven percent of those with higher levels had abnormalities. A positive acetylcholinesterase (AChE) increased the risk from 67% for levels between 2.0 and 2.4 MoM to 99% at greater than or equal to 5.0 MoMs. After a normal ultrasound and chromosome studies, the risk for a fetal abnormality was 1% for AF AFP measuring 2.0-2.4 MoM and 3% for higher levels.     

Immunocytochemical characterization of amniotic fluid macrophages in cases of fetal neural tube defects

Amniotic fluid cells from 31 pregnancies with fetuses having open neural tube defects (NTDs) and from 43 pregnancies with fetuses free of NTDs were studied with the use of the immunoperoxidase method for alpha-fetoprotein (AFP) and glial fibrillary acidic protein (GFAP). The authors also used cytochemical stains for endogenous peroxidase and nonspecific esterase activity. In cases of NTDs, macrophages were present in the amniotic fluid, and in the authors' system they showed intense immunoreactivity for both AFP and GFAP and showed very strong activity for peroxidase and nonspecific esterase, whereas the epithelial cells and red blood cells showed no activity. In six cases of anencephaly, sections from the margin of the cranial end of defective spinal cords at the aperture of the open lesion were also studied for AFP and GFAP. In these cases, AFP- and GFAP-positive cells were found, indicating the possible neural (glial) origin of a part of amniotic fluid macrophages. Although the determination of AFP levels in maternal blood and amniotic fluid is widely used in the prenatal diagnosis of NTDs, demonstration of AFP in amniotic fluid cells by means of immunocytochemistry has not been described.     

昆明地区孕中期孕妇产前筛查9137例分析

目的探讨孕妇血清标志物甲胎蛋白（AFP）和游离绒毛膜促性腺激素（Total-βhCG）、游离雌三醇对孕中期妇女进行胎儿唐氏综合征（Downssyndrome,DS）为主的先天缺陷筛查的价值。方法对孕14～21w妇女进行上述三项血清标志物检测,结合母龄、孕周、体重等因素,经过软件计算风险率,对高危孕妇进行羊水细胞染色体检查及B超进行确诊。每例受高危筛查孕妇追踪到胎儿出生。结果 9137例孕妇中,阳性率5.94%。筛查出DS高危365例,阳性率3.99%胎儿神经管畸形高危85例,阳性率0.93%,18-三体综合征高危93例阳性率1.02%,羊水细胞染色体检查及B超进行确诊4例。低危中发现唐氏综合征1例。结论利用孕妇孕中期三种血清标志物的检测,对胎儿先天缺陷产前筛查尤其是开放性神经管缺陷及胎儿染色体异常等筛查,是重要有效手段之一;产前筛查在降低围产儿死亡率,降低出生缺陷率具有重要意义。     

孕中期异常甲胎蛋白与不良妊娠结局的相关性

目的探讨孕中期甲胎蛋白(AFP)与不良妊娠结局的相关性,为妊娠管理提供建议。方法对孕中期14 008例孕妇进行唐氏筛查。研究组:①AFP MoM>2.0孕妇338例。②AFP MoM<0.5孕妇224例。依据AFP MoM值不同分组。对照组:AFP MoM值都在正常范围内的孕妇318例。回顾分析妊娠结局资料。结果①AFP MoM>2.0的孕妇发生出生缺陷(P<0.01)的机会明显比正常孕妇高。②AFP MoM>3.5的孕妇发生出生缺陷(P<0.001)和早产(P<0.05)的机会明显比正常孕妇高。③AFP MoM>5.0的孕妇发生出生缺陷(P<0.001)、早产(P<0.01)和胎儿窘迫(P<0.05)的机会明显比正常孕妇高。④AFP MoM<0.5和<0.25的孕妇均未发现与不良妊娠结局相关。结论异常水平的标志物除了能够提供开放性神经管缺损风险外,还能提供不良妊娠结局的风险信息,而这些信息对产前遗传咨询和妊娠管理是非常重要。     

胎儿水囊状淋巴管瘤的产前诊断及预后分析

目的探讨胎儿囊性淋巴瘤（cystic hygroma，CH）的产前诊断及妊娠期的处置。方法回顾性分析2006年1月～2008年4月间我院35例胎儿CH产前超声声像、介入性羊膜腔穿刺查胎儿染色体及TORCH感染情况、胎儿病理。结果发生在颈背部者33例，腋窝2例。足月分娩6例并存活，引产29例（包括死胎2例）。染色体核型分析异常者共19例，占58%，其中Turner′s综合征最常见，共11例，占33%；Down′s综合征5例，占15%；Trisomy182例，占6%；Tri-somy131例，占3%。结论超声及介入性羊膜腔穿刺查胎儿染色体在早期诊断及处置胎儿CH起决定性作用，胎儿CH与Turner综合征等染色体异常相关。     

荧光原位杂交技术在染色体非整倍体产前诊断中的应用研究

目的建立荧光原位杂交技术应用于未培养羊水标本的染色体非整倍体产前诊断。方法对于符合产前诊断指征的孕妇,于孕16-25周抽取羊水25ml,其中20ml用于传统的细胞培养和染色体G显带分析,其余5ml用荧光原位杂交方法诊断13、8、21、X、Y染色体非整倍体。结果100例受检样本中,染色体数目异常3例,其中21三体2例,45,X 1例。FISH方法与传统羊水细胞核型分析符合率100%。结论FISH技术具有快速、简便、特异的特点,可作为部分染色体非整倍体的快速产前诊断方法。     

Determination of cholinesterase and acetylcholinesterase in amniotic fluid

The determination of acetylcholinesterase (AChE) has been shown to be as specific as alphafetoprotein (AFP) for the prenatal detection of open neural tube defects although AFP remains the method of choice. This paper describes a semi-automated technique for the analysis of acetylcholinesterase in amniotic fluid that: A) reduces the cost of the procedure; B) allows for a larger number of samples to be run at a time; and C) provides for more accurate and reproducible procedures and results. Six fetuses with neural tube defects (2 with gastroschisis and 3 where one twin was dead) were detected and found to have elevated AChE, TChE and 2 bands by electrophoresis. Quality control procedures using both pure enzyme and amniotic fluid with low and high levels of the enzyme are described. The analysis of 340 amniotic fluids of normal pregnancies indicates that the normal value for AChE is 5.17 +/- 2.63 mU/ml (97% confidence interval for the mean 4.84-5.49 mU/ml. A group of 27 abnormal pregnancies provides evidence that fetal vomiting and regurgitation, fetal demise, multiple cysts syndrome, idiopathic IUGR, arthrogryposis multiplex, hydrocephaly (stenosis of aqueductus), trisomy 21, trisomy 18, hydronephrosis, pyloric stenosis, heart malformation, ectopia cordis and multiple gestation produce elevated levels of pseudocholinesterase (PChE) in amniotic fluid. The use of pseudocholinesterase levels in amniotic fluid for prenatal diagnosis is proposed and discussed in view of its elevated levels in abnormal pregnancies where AChE is normal. The normal values for PChE are 23.86 mU/ml (mean) and 5.83 for standard deviation. Electrophoretic analysis was performed on all samples with values higher than one standard deviation above the mean.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prenatal diagnosis of neural tube defects: predictive value of AF-AFP in a low-risk population

Amniotic fluid alpha-fetoprotein (AF-AFP) determinations were performed on 1,215 women who were at low risk for fetal neural tube defects and who were undergoing mid-trimester amniocentesis for cytogenetic indications, primarily age-related aneuploidy. Maternal sera obtained before amniocentesis and amniotic fluids were assayed in duplicate for alpha-fetoprotein by radioimmunoassay. Of the 1,215 low-risk women, eight (0.7%) had significant elevations of AF-AFP (greater than or equal to +5 SD). In none of the cases was the elevation associated with a fetal neural tube defect. Two cases with elevated AF-AFP were associated with chromosome aberrations; one with impending fetal demise; one with fetal blood contamination; and one case was due to a laboratory error. In one case, no source for the elevated AFP was found, and a normal infant was delivered at term. In the final two cases, the cause of the elevated AF-AFP was a fetal abdominal wall defect (one gastroschisis and one omphalocele). The predictive value of an elevated AFP varies with the population screened, and is reduced by routine ultrasonography before amniocentesis, which at least identifies anencephaly. In a low-risk population, an elevated AF-AFP is most often not associated with a fetal neural tube defect. Because of the low predictive value and the nonspecificity of AF-AFP, genetic counselors should reconsider the recommendation of routine AF-AFP in low-risk maternal populations.