7076例孕中期唐氏综合征产前筛查结果临床分析

目的 探讨孕中期唐氏综合征（DS）等筛查对检出胎儿出生缺陷和不良妊娠结局的实用价值.方法 用时间分辨荧光分析法对日照市7076名15 ～20孕周孕妇的血清甲胎蛋白（AFP）和游离绒毛膜促性腺激素（F-βHCG）进行检测,结合孕妇年龄、体重、孕周等因素,利用配套孕期胎儿唐氏综合征产前筛查分析软件,分析胎儿患DS、开放性神经管缺陷（NTD）、18-三体综合征的发病风险率,并对高风险孕妇行羊水胎儿细胞染色体核型分析或B超跟踪检查.结果 7076名孕妇中筛出高风险孕妇396例,阳性率为5.6％,在接受羊水检查的56名DS高风险孕妇中,检出唐氏胎儿3例,死胎3例,其它异常3例;对57例神经管缺陷高危孕妇进行B超检查,发现1例无脑儿;在43例18-三体高危的孕妇中,6例做羊水染色体检查,结果均正常.结论 孕中期以唐氏综合征（Ds）产前筛查作为对胎儿先天缺陷,尤其是胎儿染色体异常的筛查是行之有效方法,筛查结果呈高危孕妇须进行羊水染色体核型分析或B超检查.     

孕中期产前筛查的临床意义

目的探讨孕中期产前筛查的临床意义。方法用化学发光法对孕15w~20+6w的36294例孕妇进行产前筛查,对筛查高风险孕妇做进一步介入性胎儿羊水或脐血染色体核型分析。结果 36 294例孕中期产前筛查孕妇中,筛查高风险孕妇为2167例,筛查阳性率为5.97%;2167例高风险孕妇接受产前诊断的孕妇为821例,产前诊断率为37.89%;经羊水、脐血染色体核型分析确诊胎儿染色体异常17例(2.07%),其中唐氏综合征7例、18三体综合征2例、其它染色体异常8例;染色体多态17例(2.07%),其中9号染色体倒位有13例。结论孕中期母血清三联产前筛查是检测胎儿异常的有效途径,对降低出生缺陷,提高人口素质有重要意义。     

Down′s综合征的孕中期筛查

目的　检测孕妇血清标物甲胎蛋白(AFP)、游离- β-绒毛膜促性腺激素(Free - β-HCG)进行孕中期胎儿唐氏综合征无创伤性产前筛查。方法　采用金标定量系统对孕中期(14～2 2w)妇女进行AFP、Free - β-HCG检测,并配有唐氏综合征产前筛查专用软件进行分析校正,对筛查出的先天性缺陷胎儿,在孕妇知情的情况下,选择适宜的产前诊断。结果　接受筛查的35 8名孕妇中,唐氏综合征高风险孕妇为32例,筛查阳性率为8.94 % ,其中12例接受羊水细胞培养染色体检查,占高危孕妇的37.5 % ,检出染色体异常核型4例,占高危孕妇羊水细胞培养染色体检查的33.3%。结论　利用孕妇血清AFP、Free - β-HCG进行孕中期胎儿唐氏综合征无创伤性产前筛查,对减少病残儿的出生,具有重要意义。     

5694例单胎中孕期唐氏征血清学筛查效果分析

目的探讨孕中期唐氏征血清学筛查在检出胎儿21-三体综合征的临床应用价值,对本实验室中期唐氏征血清学筛查进行效果分析。方法采15-20^＋6孕妇静脉血进行唐氏中期三联筛查,高风险结果无创产前筛查或直接产前诊断,电话随访妊娠结局。结果唐氏征血清学筛查共检出2卜三体高风险病例379例,羊水细胞染色体核型分析共确诊胎儿21-三体综合征7例,18-三体综合征3例,13-三体综合征1例,嵌合体1例,其他染色体结构异常3例。随访结果唐氏征筛查高风险病例中,B超胎儿畸形的发生率明显高于低风险人群。结论中孕期唐氏征血清学筛查在检出胎儿21-三体综合征和B超结构异常病例中具有临床应用价值,本实验室21-三体筛查假阳性率6．5％（371／5686）,检出率62．5％（5／8）。     

Down''''s综合征的孕中期筛查

目的检测孕妇血清标物甲胎蛋白(AFP)、游离-β-绒毛膜促性腺激素(Free-β-HCG)进行孕中期胎儿唐氏综合征无创伤性产前筛查.方法采用金标定量系统对孕中期(14～22w)妇女进行AFP、Free-β-HCG检测,并配有唐氏综合征产前筛查专用软件进行分析校正,对筛查出的先天性缺陷胎儿,在孕妇知情的情况下,选择适宜的产前诊断.结果接受筛查的358名孕妇中,唐氏综合征高风险孕妇为32例,筛查阳性率为8.94%,其中12例接受羊水细胞培养染色体检查,占高危孕妇的37.5%,检出染色体异常核型4例,占高危孕妇羊水细胞培养染色体检查的33.3%.结论利用孕妇血清AFP、Free-β-HCG进行孕中期胎儿唐氏综合征无创伤性产前筛查,对减少病残儿的出生,具有重要意义.     

孕中期母血清标志物产前筛查及产前诊断临床应用价值

目的探讨孕中期母血清标志物三联筛查在唐氏综合征(DS)、18-三体综合征和神经管缺陷(NTD)的临床应用价值,评价羊水细胞培养胎儿染色体异常的临床应用价值。方法采用时间分辨免疫荧光法,对21 109例15～20+6周孕妇进行血清AFP、free!-HCG和"E3检测,结合孕妇的孕周、体重、年龄、是否双胎、有无糖尿病及吸烟史等参数,采用Multicalc风险评估软件进行风险评估;将筛查的结果与B超、羊水细胞染色体分析结果对照。结果查出973例高风险孕妇,DS高风险692例,18三体综合征高风险156例,NTD高风险125例,高风险孕妇占参检总数的4.61%。有548名孕妇参与羊水细胞培养胎儿染色体诊断,发现胎儿异常核型18例,包括21三体6例,18-三体综合征4例,其他异常核型8例,胎儿异常核型检出率为3.28%。在NTD高危125例中,确诊21例畸形儿。结论孕中期产前筛查是预测异常胎儿和不良妊娠结局的有效手段之一,羊水细胞核型分析在产前诊断中具有重要的实用价值。     

怀化地区7859例孕中期唐氏筛查和产前诊断结果分析

目的探讨孕中期唐氏筛查和产前诊断对检出胎儿染色体异常和妊娠不良结局的临床价值。方法应用时间分辨荧光免疫法对7859例孕中期(14-20周)妇女进行血清标记物三联方案(hA;FP+free-β-hCG+uE3)检测。筛查结果应用Multical软件计算21三体、18三体综合征和开放性神经管畸形的风险(rish)概率。对于高风险孕妇经遗传咨询,知情同意,自愿选择行产前诊断,于孕18-24周左右在超声引导下进行羊膜腔穿刺,抽取羊水培养进行胎儿染色体核型分析。并继续追踪胎儿和孕妇情况。结果在7859例孕妇中,筛查到高风险732例,唐氏筛查阳性率为7.65%(601/7859)。其中367例接受羊水或脐血穿刺产前诊断,占筛查高风险孕妇的50.13%(367/732);发现胎儿染色体异常16例,异常检出率4.36(16/367),其中6例唐氏综合征、5例18-三体综合征、4例Turner’s综合征、1例9号染色体臂间倒位。唐氏筛查高风险和低风险组不良妊娠结局分别为6.15%和1.46%,呈显著性差异(<0.05)。结论孕中期产前筛查是预测异常胎儿和不良妊娠结局的有效指标。结合羊水培养或脐血培养等产前诊断技术和方法,对预防先天缺陷儿出生、提高人口素质有重要临床应用价值。     

唐氏综合征产前筛查及诊断对于其它染色体异常检出的意义

目的探讨产前筛查及诊断对于检出唐氏综合征及其它染色体异常的意义。方法对孕中期妇女进行唐氏综合征筛查,对高危孕妇抽取羊水进行细胞培养及染色体核型分析。结果2375例接受羊膜腔穿刺术进行产前诊断的孕妇中,检出21-三体20例、18-三体12例,其它染色体异常核型47例。结论产前筛查及诊断不仅可以检出所筛查的目标染色体病,还可以检出其它染色体异常,是预防和降低唐氏综合征及其它染色体病患儿的出生,降低出生缺陷的有力手段。     

怀化市孕中期唐氏综合征的血清筛查和产前诊断分析

目的探讨孕中期采用甲胎蛋白(AFP)、游离β-绒毛膜促性腺激素(Free-β-HCG)、游离E3(uE3)联合筛查法在孕中期筛查唐氏综合征(DS)、神经管缺陷(NTD)及其他胎儿异常的可行性。方法应用时间分辨免疫荧光法检测孕妇血清中AFP、Free-β-HCG、uE3浓度,结合母龄、体重、孕周等个体参数,经过软件计算风险率;对高风险孕妇在知情的情况下,自愿选择进行染色体核型分析。结果 12 559例样本共筛查出高危孕妇862例,其中457例进行羊水染色体核型诊断;检出唐氏综合征儿16例,染色体结构异常27例,染色体多态11例。结论孕中期应用母血清三联法筛查,结合产前诊断是减少出生缺陷发生的有效手段之一。     

唐氏综合征孕中期产前筛查及产前诊断的临床价值

目的探讨唐氏综合征的产前筛查和产前诊断在预防出生缺陷中的价值。方法对68813例孕15-20w的孕妇采用时间分辨荧光免疫方法检测血清AFP和B-HCG浓度,通过Maiticale软件计算危险系数,对唐氏高危和18-三体高危孕妇取羊水获脐血作染色体诊断,对神经管缺陷（NTD）高危孕妇行系统超声检查。结果筛查68813例孕妇,其中2632例为唐氏综合征或18-三体综合征高分险病例,占总筛查人数的3.82%;NTD高风险542例,占0.79%。接受羊水或脐血染色体检查1772例（占总阳性数的67.32%）,检出异常核型67例,占异常发生率3.78%;NTD高风险行超声检查证实胎儿畸形58例,占筛查高危孕妇的10.7%。结论孕中期产前筛查结合产前诊断可以有效预防出生缺陷的发生。     

游离雌三醇在孕中期唐氏综合征筛查中的临床意义

目的探讨游离雌三醇（unconjugated estriol,uE3）在孕中期唐氏综合征筛查中的应用价值。方法采用时间荧光分辨免疫法测定孕中期母血清中甲胎蛋白（AFP）、游离人绒毛促性腺激素β亚单位（Free-β-hCG）和游离雌三醇水平,再采用随机配套的Wallac 2T专用风险评估软件进行教据分析,比较二联（AFP、Free-β-hCG）和三联（AFP、Free-β-hCG和uE3）唐氏综合征（Down＇s Syndrome,DS）筛查的检出率和假阳性率以评价uE3在Ds筛查中的应用价值。结果通过对绍兴妇保院2010年1月～2012年12月50188例孕中期孕妇进行产前筛查,筛查阳性检出DS 19例,漏诊7例,DS发病率1／1930;以1／270为阳性截断值,Ds三联和二联筛查方案的检出率分别为73.08％、61.54%,检出率没有明显提高,统计学上无显著差异（X2=O.79,P〉0.05）：DS三联和二联的筛查假阳性率分别为2.53％和4.15％,三联假阳性率明显低于二联（X2=204.18,P〈0.01）。结论孕中期在DS二联筛查的基础上增加uE3指标,能一定程度上提高DS检出率,能明显降低假阳性率,具有广泛的应用价值。     

Integrated screening for Down's syndrome on the basis of tests performed during the first and second trimesters.

BACKGROUND: Both first-trimester screening and second-trimester screening for Down's syndrome are effective means of selecting women for chorionic-villus sampling or amniocentesis, but there is uncertainty about which screening method should be used in practice. We propose a new screening method in which measurements obtained during both trimesters are integrated to provide a single estimate of a woman's risk of having a pregnancy affected by Down's syndrome. METHODS: We used data from published studies of various screening methods employed during the first and second trimesters. The first-trimester screening consisted of measurement of serum pregnancy-associated plasma protein A in 77 pregnancies affected by Down's syndrome and 383 unaffected pregnancies and measurements of nuchal translucency obtained by ultrasonography in 326 affected and 95,476 unaffected pregnancies. The second-trimester tests were various combinations of measurements of serum alpha-fetoprotein, unconjugated estriol, human chorionic gonadotropin, and inhibin A in 77 affected and 385 unaffected pregnancies. RESULTS: When we used a risk of 1 in 120 or greater as the cutoff to define a positive result on the integrated screening test, the rate of detection of Down's syndrome was 85 percent, with a false positive rate of 0.9 percent. To achieve the same rate of detection, current screening tests would have higher false positive rates (5 to 22 percent). If the integrated test were to replace the triple test (measurements of serum alpha-fetoprotein, unconjugated estriol, and human chorionic gonadotropin), currently used with a 5 percent false positive rate, for screening during the second trimester, the detection rate would be higher 85 percent vs. 69 percent), with a reduction of four fifths in the number of invasive diagnostic procedures and consequent losses of normal fetuses. CONCLUSIONS: The integrated test detects more cases of Down's syndrome with a much lower false positive rate than the best currently available test.     

Serial first- and second-trimester Down's syndrome screening tests among IVF-versus naturally-conceived singletons

BACKGROUND: It has been reported that second-trimester serum markers may be affected by assisted reproduction, leading to a higher false-positive rate. METHODS: A total of 285 naturally and 71 IVF-conceived singletons which underwent a serial disclosure Down's syndrome screening programme were compared. The study protocol included first-trimester combined [nuchal translucency (NT), free beta-HCG and pregnancy-associated plasma protein-A (PAPP-A)] testing. The second-trimester triple serum screening included alpha-fetoprotein (AFP), intact HCG and unconjugated estriol (uE3). After excluding aneuploidies, miscarriages, anatomical anomalies and cases with incomplete follow-up, the serum samples of normal cases were assessed and correlated. RESULTS: NT measurement was not significantly changed in either group. However, the IVF group had lower PAPP-A [0.96 versus 1.05 multiples of normal median (MoM)] and higher AFP (1.13 versus 1.07 median MoM). Both groups had similar rates of first-trimester false-positive results (FPR; 7 and 9% respectively), but the IVF group had a significantly higher mid-gestation FPR rate (10 versus 5%; Pearson chi2, P = 0.029). This has contributed to amniocentesis uptake rates of 15 and 13% for the IVF and natural conception pregnancies respectively. CONCLUSIONS: The IVF group tended to have a significantly higher second-trimester FPR rate. To counterbalance this phenomenon, integrated first- and second-trimester screening tests or the use of NT alone might be a reasonable option that deserves further investigation.     

5933例孕中期母血清产前筛查回顾性分析与诊断

目的探讨孕中期母血清三联筛查法的临床意义及了解枣庄地区21-三体综合征（唐氏综合症）、18-三体综合征及NTD（神经管畸形）的发病率,旨在促进枣庄市产前筛查工作的更好开展。方法采用时间分辨荧光免疫分析法（DELFIA）对枣庄市产前诊断中心自2012年10月至2013年10月采集的5933个标本进行三联法孕中期母血清产前筛查。结果5933例孕妇中446例高风险,总体高风险率是7.5%;其中21-三体综合征高风险324例,高风险率是5.5%;18-三体高风险101例,高风险率是1.7%;NTD高风险21例,高风险率是0.4%。在自愿以及知情基础上经遗传咨询后有164例高风险孕妇行产前诊断,共确诊8例,确诊率是4.8%,其中21三体综合征4例,NTD 2例,畸胎瘤1例,三X综合征1例。结论结果表明孕中期母血清三联筛查法对于预测胎儿染色体病具有重要临床价值,可有效降低新生儿出生缺陷的发生;扩大产筛覆盖率,对实施出生干预工程,提高出生人口素质有重大意义。     

Comparison between disclosure and non-disclosure approaches for trisomy 21 screening tests

BACKGROUND: First-trimester nuchal translucency (NT) and second-trimester triple test (TT) are common screening programmes for trisomy 21. The aim of this study was to compare disclosure and non-disclosure approaches of combining those tests. METHODS: Likelihood ratios of both NT and TT tests, among 508 normal and 23 trisomy 21-affected pregnancies, were used for calculating population-adjusted risks. Disclosure approach incorporated all cases which, by either NT or TT, exhibited a risk > or = 1:250 whereas non-disclosure approach generated a new integrated figure > or = 1:250. RESULTS: Among women aged < or = 34 years, the disclosure and non-disclosure approaches were associated with false positive rates of 4.3 and 1.1%, detection rates of 76.4 and 61.2%, positive predictive value (PPV) of 1:53 and 1:17, and false negative rate of 1:3129 and 1:1985 respectively. CONCLUSIONS: The disclosure approach resulted in considerably higher detection rates. The non-disclosure approach, however, was four times better regarding the number of invasive procedures required to detect one case of trisomy 21. However, the positive predictive value associated with the disclosure policy was still much more beneficial than that obtained in women aged > or = 37 years, who are routinely referred to fetal karyotyping.     

Korean-specific parameter models for calculating the risk of Down syndrome in the second trimester of pregnancy

The purpose of the current study was to propose a Korean-specific parameter set for calculating the risk of Down syndrome in the second trimester of pregnancy and to determine the screening performances of triple and quadruple tests in Korean women. Using the data on triple or quadruple screening from three hospitals in Korea during 7 yr, we re-converted the concentrations of four serum markers to multiple of median values according to gestational age and maternal weight. After re-calculating the risk of Down syndrome in each pregnancy by multiplying maternal age-specific risk by the likelihood ratio values for the serum markers, screening performances and optimal cut-off values of triple and quadruple tests were analyzed. Among 16,077 pregnancies, 23 cases had Down syndrome (1.4/1,000 deliveries). Compared to the previous program, the tests with new parameters had improved screening performance. The triple and quadruple tests had detection rates of 65.2% and 72.7%, respectively, at a false-positive rate of 5%. The optimal cut-off value for the quadruple and triple tests was 1:250. We have presented a Korean-specific parameter set for Down syndrome screening. The proposed screening test using this parameter set may improve the performance of Down syndrome screening for Korean women.     

Cell-free fetal DNA levels in pregnancies conceived by IVF

BACKGROUND: Increased second-trimester levels of maternal serum HCG in IVF conceptions lead to an increased false-positive rate in Down syndrome screening. Increased levels of cell-free fetal DNA (cffDNA) in maternal plasma have been correlated with increased HCG levels. Our aim was to determine whether cffDNA levels are elevated in IVF pregnancies compared with natural pregnancies. METHODS: Sixteen archived second-trimester serum samples from IVF pregnancies were matched with five control samples from naturally conceived pregnancies per case, all carrying a singleton male fetus. cffDNA concentrations were measured by real-time PCR amplification of a Y chromosome sequence and compared with four standard second trimester serum screening markers (alpha-fetoprotein, estriol, HCG and inhibin A). RESULTS: Mean cffDNA levels for cases and controls were 57.9 and 57.1 genome equivalents/ml, respectively (P = 0.95). Mean observed rank (from 1 to 6) of cffDNA was 3.625 in the IVF conceived group, compared with an expected value of 3.5 (P = 0.53). No significant correlations were observed between cffDNA and serum markers. CONCLUSIONS: IVF does not affect levels of cffDNA, which appears to be independent of traditional screening markers (e.g. HCG). Therefore, cffDNA can be used as an additional serum marker (e.g. Down syndrome screening) without adjustment for IVF pregnancies.     

中山地区孕中期唐氏综合征筛查的应用

目的探讨孕中期血清学筛查唐氏综合征在中山地区的应用。方法采用时间分辨荧光免疫技术,对2009年1月到2009年6月中山23家镇区及本院的共9146例孕14周~20周的妇女进行血清AFP、F-βHCG、uE3的检测,并对筛查出的高风险孕妇进行羊水或脐血染色体确诊,所有筛查孕妇都进行随访到分娩后。结果筛查的9146例孕妇中,高风险789例,确诊21三体3例,18三体3例,NTD 1例,筛查阳性率8.63%,确诊率0.89%。筛查阴性的孕妇中检出21三体1例,唐氏综合征的检出率为75%(3/4)。根据中山地区筛查数据建立了该地区各孕周筛查指标的中位数值。结论孕中期血清学筛查唐氏综合征的方法有提高检出染色体异常胎儿的作用,对减少出生缺陷、提高人口素质有重要意义。因考虑到各民族、各地区的差异,建立实验室自己的筛查指标中位数值,以提高检出率,减低假阳性率。     

Role of screening agar plates for in vitro susceptibility testing of Helicobacter pylori in a routine laboratory setting

BACKGROUND: Resistance of Helicobacter pylori to the more frequently used antibiotics (metronidazole and clarithromycin) reduces eradication rates even with triple treatment. Determining the antibiogram profile of H pylori can take up to 14 days and delays appropriate treatment. AIMS: To determine the role of screening agar plates for more rapid in vitro susceptibility of H pylori to metronidazole, amoxicillin, and clarithromycin. METHODS: Routine gastric biopsy specimens from 507 dyspeptic patients were inoculated on to 10% lysed blood agar plates containing metronidazole (8 microg/ml), clarithromycin (2 microg/ml), or amoxicillin (0.5 microg/ml). The minimum inhibitory concentration (MIC) of the 90 isolates was determined using the E test. RESULTS: Metronidazole resistance was detected in 28 of 90 isolates by E test and nine of 98 by screening agar. The screening agar detected none of the four clarithromycin resistant isolates detected by the E test. CONCLUSIONS: The screening agar method is not sufficiently sensitive to be used alone.     

Second-trimester maternal serum screening for Down's syndrome: free beta-human chorionic gonadotrophin (HCG) and alpha-fetoprotein, with or without unconjugated oestriol, compared with total HCG, alpha- fetoprotein and unconjugated oestriol

The aim of our study was to compare three protocols for second- trimester maternal serum screening for Down's syndrome in the same serum samples, using two triple tests [total human chorionic gonadotrophin (HCG), alpha-fetoprotein, unconjugated oestriol; and free beta-HCG, alpha-fetoprotein, unconjugated oestriol] and a double test (free beta-HCG and alpha-fetoprotein). The three protocols were compared in a series of 23 serum samples from Down's syndrome pregnancies and in a cohort of 2516 pregnant women receiving routine antenatal care between June 1992 and June 1993. Among the 23 affected cases, at a cut-off risk of 1:380, the detection rate of Down's syndrome was comparable with the double test (74%; 17/23) and the triple tests (65%; 15/23) (not significantly different). At the same cut-off risk, in the cohort of 2516 pregnant women screened between 15 and 18 weeks gestation, both protocols using free beta-HCG achieved a significant reduction of the number of false positive cases (P = 0.013 and 0.004 for double and triple tests respectively). We conclude that, compared to total HCG, alpha-fetoprotein and unconjugated oestriol, use of free beta-HCG and alpha-fetoprotein represents a better second- trimester screening test for Down's syndrome, because it significantly decreases the false positive rate at a lower running cost. The addition of unconjugated oestriol to the double test adds no further advantage.