超声探测颈部透明带检出胎儿染色体异常

目的：评价超声探测颈部透明带或颈部水肿在检出胎儿染色体异常方面的作用。方法：于孕10－14周测量胎儿颈部透明带厚度，或孕14周后测量胎儿颈部皮肤厚度，并随诊观察，结果：通过超声探测共检出12例非整倍体型染色体异常的胎儿，5例正常染色体但随诊发现严重并发症的胎儿，与颈部透明带增厚但染色体及颈后正常的胎儿相比，上述异常胎儿在孕10－14周时的颈部透明带显著增厚（平均厚度6．1mm对3．6mm)，且大多数进展为妊娠中期时的颈部水肿，并合并其他超声异常。结论：超声测量颈部透明带厚度能早期有效地检出染色体异常及合并其他严重并发症的胎儿，且超声随诊观察颈部透明带厚度的变化对于鉴别诊断及评价预后有很大帮助。     

产前超声检测颈部透明带厚度在胎儿染色体异常筛查中的价值

目的 评价超声检测颈部透明带厚度在胎儿染色体异常筛查中的作用,从而提高染色体异常胎儿的诊断率.方法 于胎体正中矢状切面测量颈部透明带厚度,妊娠10 ～14 周的孕妇测量胎儿颈部透明带厚度,妊娠14 ～16 周孕妇测量胎儿颈项部皮肤厚度,共计610 例.对妊娠10 ～13 周颈部透明带厚度≥3.0 mm 的胎儿或妊娠14 ～16 周颈项部皮肤厚度≥6.0 mm 的胎儿进行染色体核型分析,并收集其父母行为的相关资料.结果 17 例因颈部透明带或颈项部皮肤增厚进行了染色体核型分析检查,显示8 例胎儿为正常染色体核型,9 例胎儿为非整倍体染色体核型.本组资料中,染色体核型正常胎儿平均颈部透明带厚度(3.7 mm)明显小于异常组(6.0 mm).大多数染色体核型正常的胎儿妊娠早期显示的颈部透明带增厚在妊娠14 周后会自行消退.染色体核型异常的胎儿大多数于妊娠中期进展为颈项部皮肤水肿或虽未进展为颈项部皮肤水肿但合并其他畸形.父母的行为与其胎儿染色体核型正常或异常关系不大.结论 在妊娠早中期检测胎儿的颈部透明带厚度并密切随诊观察其变化,对染色体核型异常胎儿及高危胎儿的检出有重大意义,同时对胎儿畸形的鉴别诊断及判断胎儿预后等也有重要作用.     

胎儿颈项透明层增厚与染色体异常相关性研究

目的:探究胎儿颈项透明层增厚、染色体异常之间的相关性。方法:选择2019年6月—2022年2月于宿迁市第一人民医院行孕期检查的孕妇54例为研究对象,患者均进行超声检查,测量胎儿颈项透明层厚度,预测胎儿染色体异常发生。结果:羊水穿刺诊断出胎儿染色体异常8例,包括21三体1例,18三体1例,性染色体异常1例,15号染色体微缺失1例,2号染色体微缺失1例,4号染色体微重复1例,7号染色体微缺失1例。其中21三体、18三体为NT增厚伴母亲年龄偏大,胎儿异常主要为鼻骨缺失。超声检查颈项透明层增厚结果:厚度2.5～3.0 mm病例11例,染色体异常0例;26例胎儿颈项透明层厚度3.1～4.0 mm,染色体异常4例;12例胎儿颈项透明层厚度4.1～5.0 mm,2例确诊为染色体异常;厚度> 5mm病例5例,染色体异常2例。超声检查颈项透明层增厚对胎儿染色体异常的诊断符合率、灵敏度与特异度分别为98.15%、87.50%、100.00%,与羊水穿刺结果比较,差异无统计学意义(P> 0.05)。结论:超声检查结果显示胎儿颈项透明层厚度与胎儿染色体异常存在内在关系。     

超声检查颈项透明层厚度在胎儿染色体异常中的诊断效果及与预后的相关性研究

目的探讨超声检查颈项透明层厚度对胎儿染色体异常患儿预后的相关性。方法选择2016年3月～2018年2月于我院进行产前超声检查的孕妇896例作为研究对象,所有胎儿均进行超声NT标准化测量,记录胎儿染色体异常情况;采用Pearson相关性分析对胎儿染色体异常预后与颈项透明层厚度进行相关性分析。结果 896例孕妇均完成颈项透明层厚度检查,其中NT2.5mm17例,阳性率为1.90%;NT增厚胎儿测量值为2.5～11.86(6.46±1.21)mm;17例NT异常胎儿经病理、随访最终均确诊异常,Pearson相关性分析结果表明:胎儿染色体异常发生率与NT厚度呈正相关性(P0.05)。结论超声检查颈项透明层厚度用于胎儿染色体异常中能获得较高的诊断准确率,且与预后存在相关性,能为临床诊疗提供依据和参考,值得推广应用。     

经腹超声联合经阴道超声在判别早孕期胎儿结构异常中的临床价值

目的探讨经腹超声联合经阴道超声在早孕期胎儿结构异常中的应用价值。方法 70例孕9～14周孕妇行经腹超声联合经阴道超声检查,分析胎儿结构异常者的声像图表现。所有结构异常者均经中孕期超声复查或引产后病理证实。结果 70例高危受检孕妇中,超声检出胎儿结构异常者27例,随访25例,失访2例。1例联体双胎漏诊,其余均与超声诊断结果一致;8例为单纯颈项透明层厚度增厚;余19例结构明显异常胎儿中,8例合并染色体异常,7例合并颈项透明层厚度增厚,4例合并水囊瘤。结论经腹超声联合经阴道超声检查提高了胎儿畸形的早期检出,对胎儿畸形早期筛查具有显著的临床价值。规范化及切面标准化是减少漏误诊的重要措施。     

孕早期颈项透明层厚度测量在胎儿产前诊断中的应用分析

目的探讨孕早期超声测量胎儿颈项透明层(nuchal translucency,NT)厚度在产前诊断胎儿染色体疾病及其他结构畸形中的临床价值。方法对2008年9月—2009年8月期间的227名孕11~13+6周胎儿进行NT厚度标准测量,分析NT增厚胎儿的染色体核型、结构及妊娠结局。结果 NT厚度<2.5 mm的胎儿中,染色体及结构正常211例,染色体或结构异常2例。NT厚度≥2.5 mm的胎儿中,6例染色体异常(13-三体综合征1例、18-三体综合征1例、21-三体综合征3例、45X0 1例);3例结构畸形(胎儿多发性结构异常1例、先天性心脏病2例);1例孕20周前不明原因流产;4例无染色体及其他结构异常。正常胎儿的NT厚度呈正态分布,NT厚度随胎龄增加而增厚,男性与女性的NT厚度差异无统计学意义。正常胎儿与异常胎儿头臀长差异无统计学意义;NT厚度异常胎儿的孕妇年龄大于NT厚度正常的孕妇。超声测量NT厚度值设为2.5 mm时,检测胎儿早期异常的灵敏度与特异度比较平衡,分别为80.0%和97.0%。结论 NT厚度的标准化测量是一个早期对胎儿染色体异常、结构异常,尤其是胎儿先天性心脏病筛查的重要指标,有助于早期诊断染色体疾病及其他结构异常,对评价胎儿预后具有较高的临床价值。     

超声检出异常胎儿的染色体情况分析

目的探讨超声检出异常胎儿的染色体情况。方法对我院经超声检查发现的53例异常胎儿行羊膜腔穿刺取羊水做染色体核型分析。结果超声检查发现的53例异常胎儿中,染色体异常9例,检出率17%。其中,染色体数目异常6例,染色体多态性变异核型2例,嵌合体1例。9例染色体异常中,其超声提示颈项透明层增厚3例,颈项软组织增厚1例,颈部淋巴水囊瘤合并水肿同时脐动脉收缩期最大速率与舒张末期血流速率比值增高1例,单纯脐动脉收缩期最大速率与舒张末期血流速率比值增高1例,腹部囊性占位1例,心包积液1例,心室灶状强回声1例。结论超声检出的异常胎儿中,染色体异常发生率并不高;胎儿某些部位的异常可在一定程度上提示胎儿染色体异常,临床上可针对特定的胎儿异常进行针对性的羊膜腔穿刺,以避免盲目穿刺带来的创伤。     

超声探讨胎儿颈项部软组织厚度与先天性心脏疾病的关系

目的评估在中孕早期对胎儿颈项部软组织厚度（nuchal fold,NF）的测量对检出胎儿早期先天性心脏病的临床诊断价值。方法2008年1月～2009年1月,在孕14～23周对胎儿颈项部软组织NF厚度进行测量,同时在20-26周对胎儿进行系统详细超声检查及胎儿超声心动图检查,对相关胎儿进行染色体检查。结果超声共对11,421例胎儿检查,对其中1,334例胎儿进行NF测量,共检出NF增厚胎儿69例,检出患心脏主要畸形的胎儿94例,其中533例进行染色体检查,485例染色体正常,这其中查出心脏畸形28例（5．7％）。染色体异常组中有18例接受胎儿心超检查．查出心脏畸形6例（33．3％）。在染色体正常的胎儿中,心脏畸形检出率从4．8％（NF〈6mm）上升到22．2％（NF≥6mm）。结论超声探察胎儿NF对胎儿心脏疾病的检出具有较好的早期提示作用,并可指导临床预测胎儿的预后。     

超声检查应用在胎儿颈项透明层厚度中对筛查胎儿染色体异常的临床价值分析

目的:探究超声检查应用在胎儿颈项透明层(nuchal translucency,NT)厚度中对胎儿染色体异常筛查的临床价值。方法:选取迁安市中医医院2021年4月—2022年4月收治的200例经超声显示胎儿颈项透明层异常而接受羊水染色体核型分析的孕妇为研究对象,对其超声检查结果与羊水染色体核型检测的结果进行分析。结果:200例受检者中,22.50%的胎儿染色体异常,其中染色体数目异常占86.67%,结构异常占8.89%,嵌合体占4.44%。染色体数目异常中,21-三体综合征的发生率最高,与其他染色体异常类型发生率比较差异有统计学意义(P<0.05);胎儿染色体异常率随着其颈项透明层值的增加而逐渐增高,差异有统计学意义(P<0.05)。结论:采用超声对胎儿进行颈项透明层厚度的检查,可为胎儿染色体异常的筛查提供一定的指导依据,颈项透明层值越高,其染色体核型异常的检出率越高。     

孕早期超声测量胎儿颈项透明层厚度在产前诊断中的应用价值

目的探讨孕早期应用超声测量胎儿颈项透明层(NT)厚度在产前诊断中的应用价值。方法选取我院接受孕早期胎儿系统性产前超声筛查的单胎胎儿2850例,分别测量其头臀径、NT厚度、鼻骨及静脉导管血流频谱等,对孕早期NT增厚(≥2.5 mm)的孕妇于中晚期复查超声,分析NT厚度与异常妊娠的关系。结果孕早期超声检查发现NT厚度<2.5 mm胎儿染色体异常、结构畸形、水囊状淋巴管瘤及胚胎停止发育等异常妊娠的发生率为0.89%,较NT厚度≥2.5 mm胎儿异常妊娠发生率(77.20%)低,差异有统计学意义(P<0.05);44例NT厚度≥2.5 mm胎儿检出染色体核型异常13例,正常21例;NT厚度的增加与异常妊娠的发生率呈正相关(r=0.734,P<0.05)。结论孕早期胎儿NT增厚与胎儿染色体异常及结构畸形等异常妊娠的发生具有相关性,可作为胎儿产前超声筛查的常规项目。     

The role of fetal nuchal translucency and ductus venosus Doppler at 11-14 weeks of gestation in the detection of major congenital heart defects.

OBJECTIVE: To determine whether, in a selected high-risk population, Doppler velocimetry of the ductus venosus can improve the predictive capacity of increased nuchal translucency in the detection of major congenital heart defects in chromosomally normal fetuses at 11-14 weeks of gestation. METHODS: Ductus venosus Doppler ultrasound blood velocity waveforms were obtained prospectively at 11-14 weeks of gestation in 1040 consecutive singleton pregnancies. Waveforms were classified either as normal in the presence of a positive A-wave, or as abnormal if the A-wave was absent or negative. All cases were screened for chromosomal defects by a combination of maternal age and fetal nuchal translucency thickness. In 484 cases karyotyping was performed. Those fetuses found to be chromosomally normal by prenatal cytogenetic analysis, and which had abnormally increased nuchal translucency and/or abnormal ductus venosus Doppler velocimetry, underwent fetal echocardiography at 14-16 weeks of gestation. Ultrasound examination was repeated at 22-24 weeks of gestation in all women. The sensitivity, specificity and positive and negative predictive values for the detection of major cardiac defects of increased nuchal translucency thickness alone, ductus venosus Doppler alone and increased nuchal translucency thickness in association with abnormal ductus venosus Doppler were determined. RESULTS: In 29 of 998 fetuses presumed to be chromosomally normal, reversed or absent flow during atrial contraction was associated with increased (> 95(th) centile for crown-rump length) nuchal translucency. Major cardiac defects were observed in 9 of these 29 fetuses. No other major cardiac abnormalities were found in chromosomally normal fetuses in spite of the presence of either increased nuchal translucency alone or abnormal ductus venosus velocimetry. A total of 25 cardiac malformations were observed in the population. Fifteen were associated with aneuploidy and 10 fetuses had a normal karyotype. Nine of the 10 had major cardiac anomalies and one had a ventricular septal defect. The nine cases with normal karyotype and major cardiac anomalies had both increased nuchal translucency and abnormal ductus venosus flow velocity waveforms. CONCLUSION: In chromosomally normal fetuses with increased nuchal translucency, assessment of ductus venosus blood flow velocimetry could improve the predictive capacity for an underlying major cardiac defect.     

Cardiac defects in chromosomally normal fetuses with abnormal ductus venosus blood flow at 10-14 weeks.

OBJECTIVE: To assess a possible relationship between ductus venosus blood flow abnormalities and cardiac defects in chromosomally normal fetuses with increased nuchal translucency thickness at 10-14 weeks of gestation. METHODS: Ductus venosus Doppler ultrasound blood flow velocity waveforms were obtained at 10-14 weeks' gestation immediately before fetal karyotyping in 200 consecutive singleton pregnancies with increased nuchal translucency. Fetal echocardiography was subsequently carried out in those with normal fetal karyotype. RESULTS: Reverse or absent flow during atrial contraction was observed in 11 of the 142 chromosomally normal fetuses with increased nuchal translucency. Major defects of the heart and/or great arteries were present in seven of the 11 with abnormal ductal flow and increased nuchal translucency, but in none of the 131 with normal flow. CONCLUSION: These preliminary results suggest that abnormal ductus venosus blood flow in chromosomally normal fetuses with increased nuchal translucency identifies those with an underlying major cardiac defect.     

Ultrasonographic markers for chromosomal abnormalities in women with negative nuchal translucency and second trimester maternal serum biochemistry.

OBJECTIVE: To analyze the value of second trimester ultrasound examination among those women whose fetuses were indicated to be at low risk of chromosomal anomalies on the basis of both first trimester nuchal translucency measurement and second trimester biochemical screening. METHODS: A retrospective study of 5500 pregnancies carried out at the fetal medicine unit, Royal Free Hospital. During a period of over 3 years 5500 pregnancies underwent a first trimester scan and nuchal translucency measurement which enabled the detection of 62% (20 of 32) of all chromosomal anomalies. From the remaining pregnancies that underwent second trimester biochemical screening, 3548 were considered negative (risk < 1:250; using maternal serum free beta human chorionic gonadotrophin and alpha fetoprotein). The ultrasound markers that were examined were: shortened femur length, echogenic bowel, pyelectasis, choroid plexus cysts and echogenic intracardiac foci. The likelihood ratios for chromosomal aneuploides for each of these markers were calculated. RESULTS: Of the 3548 screen negative pregnancies, 3541 (99.8%) had a normal karyotype. Seven (0.2%) fetuses had an abnormal karyotype including four (0.11%) with trisomy 21, one with trisomy 18 and two with 47XXY. Second trimester ultrasound markers were found in two of the five (40%) with severe chromosomal anomalies compared to 184 of 3541 (5.2%) with normal karyotypes. Detection of one or more ultrasound markers in a screen negative pregnancy increased the possibility of chromosomal aneuploidy and a negative ultrasound decreased the risk by a likelihood ratio of 0.6 (95% confidence interval, 0.3-1.3). The risk was considerably increased when two or more markers were detected and we would recommend karyotyping under these circumstances. CONCLUSION: This preliminary data indicates a possible role for abnormal ultrasound markers in assessing the risk of chromosomal abnormalities in patients considered to be at low risk by nuchal translucency and serum screening. However analysis of a much larger study group will have to be conducted to assess the significance of individual markers.     

中晚孕期胎儿鼻骨缺失及染色体异常的超声诊断分析

目的：探讨孕16-34周超声筛查胎儿鼻骨缺失在染色体异常诊断中的应用价值。方法2008至2013年中晚孕期在北京协和医院超声筛查发现鼻骨缺失的20例胎儿均行染色体检查并随访至引产或出生后,总结胎儿鼻骨缺失超声声像图特征。结果20例胎儿产前超声显示：（1）双侧鼻骨缺失17例,面部正中矢状切面及横切面扫查均不能显示鼻梁皮肤下方的鼻骨强回声。其中5例胎儿合并多发畸形：4例胎儿心脏畸形（房室间隔缺损3例,房室间隔缺损合并大血管异常1例）,1例胎儿十二指肠梗阻。其他微小结构异常包括：股骨及肱骨短,肠管回声增强,迷走右锁骨下动脉,单侧侧脑室临界增宽,双肾盂轻度增宽,吐舌征,双手姿势形态异常。（2）单侧鼻骨缺失3例,面部横切面扫查仅能显示胎儿一侧鼻骨强回声。其中2例合并心脏畸形（房室间隔缺损1例,室间隔缺损1例）;合并其他微小结构异常包括：股骨及肱骨短,肠管回声增强,颈背部皮肤增厚。（3）染色体检查：17例双侧鼻骨缺失胎儿中9例为21-三体,1例为4p-（Wolf-Hirschhorn综合征）,7例为正常核型;3例单侧鼻骨缺失胎儿中2例为21-三体,1例为正常核型。（4）产后检查及随访：20例胎儿超声及染色体检查后引产12例（尸检1例）,出生8例,5例随访无明显异常,3例失访;12例胎儿产前超声与产后检查结果均符合。结论中晚孕期鼻骨缺失胎儿超声图像特征为双侧或单侧鼻骨强回声缺失,且多伴微小结构异常,超声检出胎儿鼻骨缺失应行染色体核型分析,减少21-三体等染色体异常胎儿的出生。     

Fetal nuchal translucency screening in 12495 pregnancies in Sardinia.

OBJECTIVE: To examine the distribution of fetal nuchal translucency thickness in normal and chromosomally abnormal fetuses in Sardinia and to determine the effectiveness of screening by a combination of fetal nuchal translucency and maternal age. METHODS: Fetal nuchal translucency thickness and crown-rump length were measured at 10-14 weeks of gestation in 12 495 pregnancies. A reference range of fetal nuchal translucency thickness for crown-rump length was determined from the 10 001 singleton pregnancies with known normal pregnancy outcome. The median nuchal translucency thickness for crown-rump length was determined by regression analysis of the calculated median values of nuchal translucency thickness for each 0.1 mm interval in crown-rump length. The proportions of unaffected fetuses and those with trisomy 21 or other chromosomal defects with nuchal translucency thickness > 1.5 and 2.0 multiples of the regressed normal median for crown-rump length were calculated. The distribution of estimated risks based on maternal age and fetal nuchal translucency thickness according to The Fetal Medicine Foundation software were also determined and the sensitivity and false-positive rates were calculated. RESULTS: In the 10 001 normal pregnancies, the median fetal nuchal translucency thickness increased with crown-rump length (median nuchal translucency thickness = 0.3496 + 0.018 x crown-rump length) (r2 = 0.4411). In the singleton pregnancies, there were 64 fetuses with trisomy 21 and 46 with other chromosomal defects. The fetal nuchal translucency thickness was > 1.5 multiples of the median in 510 (5%) of the normal fetuses, in 52 (81%) of the trisomy 21 fetuses and in 33 (72%) of those with other chromosomal defects. The respective values for nuchal translucency thickness > 2.0 multiples of the median were 195 (2%), 41 (64%) and 32 (70%). In 184 multiple pregnancies, there were four fetuses with chromosomal abnormalities and in three of these the nuchal translucency thickness was > 1.5 multiples of the median. Screening by a combination of maternal age and fetal nuchal translucency thickness with a risk cut-off of 1 in 300 identified 90% of trisomy 21 pregnancies and 85% of all other chromosomal defects for a false-positive rate of 9%. CONCLUSION: Screening for chromosomal defects by measurement of nuchal translucency thickness identifies 80% of fetuses with trisomy 21 for a false-positive rate of 5%. In our population with a median maternal age of 33 years, screening by a combination of maternal age and fetal nuchal translucency thickness with a risk cut-off of 1 in 300 identified 90% of trisomy 21 pregnancies for a false-positive rate of 9%.     

Fetal cardiac abnormalities identified prior to 14 weeks' gestation.

OBJECTIVE: An increasing number of patients are presenting at early gestational age as being at high risk for congenital heart disease, as a result of ultrasound screening by nuchal translucency. The feasibility and accuracy of fetal echocardiography was assessed in a series of pregnancies studied before 14 weeks' gestation. METHODS: Echocardiography was attempted in 478 fetuses of crown-rump length 40.0-85.0 mm (median, 60.3 mm) with increased nuchal translucency, suspected abnormalities on routine scan or a family history of heart defect. The findings were related to results of autopsy, karyotyping, later scans and postnatal follow-up. RESULTS: Satisfactory images were obtained transabdominally in 402/478 (84.1%) and transvaginally in a further 13 patients. Cardiac defects were confidently identified in 60 fetuses and abnormalities of uncertain significance (isolated ventricular or great artery disproportion, or tricuspid regurgitation) were observed in a further 49. Defects were suspected in an additional 20 fetuses, and 286 were passed as normal. The karyotype was subsequently demonstrated to be abnormal in 70/286 (24.5%) fetuses with normal echocardiograms, and in 94/129 (72.9%) with abnormal or suspicious cardiac findings. Validation of the scan findings was possible in 241 fetuses. Normal heart structure was confirmed in 204 fetuses, and previously unsuspected cardiac abnormalities revealed in nine. Heart defects were verified in 28 fetuses, but five of these had important additional findings. There were false positive findings in three fetuses. CONCLUSIONS: Fetal echocardiography is feasible prior to 14 weeks' gestation. Cardiac defects, when present, may be identified or suspected in the majority of cases. In the risk group studied, heart defects were frequently a manifestation of chromosomal abnormality.     

21-三体胎儿的孕中期超声检出

目的　探讨产前超声检查在检出 2 1 三体胎儿方面的作用。方法　在孕中期进行超声检查 ,观察胎儿生长发育 ,测量胎儿颈背部皮肤厚度 ,并除外严重胎儿畸形。结果　通过超声检查发现颈背部皮肤增厚 ,于孕 14～ 2 1周检出了 3例 2 1 三体胎儿 ,其中 2例母亲年龄小于 3 5岁 ,且无其他超声异常表现等染色体核型检查适应证。在没有应用这一超声指标进行产前筛查的 6例 2 1 三体病例中 ,母亲年龄小于 3 5岁的 2例被漏诊。结论　应用颈背部皮肤增厚这一超声指标可以提高产前 2 1 三体胎儿检出率 ,特别是母亲年龄小于 3 5岁 ,且不合并严重畸形的病例 ,减少产前漏诊。     

Significance of chromosome 22q11 analysis after detection of an increased first-trimester nuchal translucency.

OBJECTIVE: To determine the value of performing routine fluorescent in situ hybridization (FISH) for microdeletions of chromosome 22q11 when karyotyping fetuses with increased nuchal translucency. DESIGN: This was a prospective observational study carried out over an 18-month period. Fetal karyotyping by chorionic villus sampling was offered to 5429 women attending for a routine booking scan in the first trimester when their nuchal translucency adjusted risk for Down syndrome was > or = 1 in 300. Cytogenetic samples were routinely tested for the 22q11 microdeletion when the nuchal translucency was > or = 3 mm. RESULTS: The prevalence of increased nuchal translucency > or = 2.5 mm was 180 (3.3%) and > or = 3.5 mm was 42 (0.8%). None of 75 fetuses with an increased nuchal translucency and normal karyotype demonstrated a 22q11 microdeletion on FISH analysis. In the same cohort, 3 of 20 (15%) cases of major congenital heart defects in which nuchal translucency was measured, had a nuchal translucency measurement > or = 2.5 mm. CONCLUSIONS: Routine FISH analysis for chromosome 22q11 microdeletions at the time of chorionic villus sampling for increased first-trimester nuchal translucency is of limited value. As a significant proportion of fetuses with increased nuchal translucency will be found to have congenital heart defects later in the pregnancy, FISH analysis for chromosome 22q11 microdeletions can be targeted to fetuses with specific congenital heart defects. Tissue from the chorionic villus sampling should therefore be stored for subsequent analysis, until after detailed echocardiography is performed.     

First trimester isolated fetal nuchal lucency: significance and outcome

In this study, we determined the outcome in cases of isolated nuchal lucency seen sonographically in the first trimester in fetuses without karyotypic abnormalities. We reviewed all cases of isolated localized fetal nuchal lucency (3 mm or greater) in 9 to 14 week fetuses over a 4 year period. Fetuses with additional sonographic abnormalities were excluded. The width of the nuchal lucency at initial sonogram as well as findings on subsequent scans were tabulated. Karyotypic, pathologic, and clinical follow-up data were obtained. Of 44 fetuses with an isolated, localized first trimester nuchal lucency, one was lost to follow-up and two were excluded owing to pregnancy termination without karyotype or pathologic analysis, thus resulting in 41 fetuses in our study group. Five fetuses (12%) had abnormal karyotypes. Twenty-seven of the remaining 36 fetuses had normal karyotypes, eight others showed no evidence of aneuploidy at birth, and one patient underwent spontaneous abortion prior to a karyotypic analysis. Among the 36 fetuses without evidence of aneuploidy, six had a poor outcome: two were spontaneous abortions, one was a therapeutic abortion of a fetus with hydrops and a pericardial effusion seen on fetopsy; one fetus died at birth of pulmonary hypoplasia associated with autosomal recessive polycystic kidney disease, and one fetus each had Noonan syndrome, and Joubert syndrome. In addition, three patients delivered their infants prematurely. Overall, 32 of 41 fetuses survived, and two (6%) were abnormal. Excluding premature infants, 27 were normally grown, term survivors. We conclude that other than having an increased risk for aneuploidy, fetuses with isolated nuchal lucency are also at risk for spontaneous miscarriage, premature delivery, and congenital anomalies unassociated with an abnormal karyotype.     

Nuchal translucency thickness and crown-rump length in twin pregnancies with chromosomally abnormal fetuses.

We retrospectively examined the crown-rump length and nuchal translucency thickness of each fetus in eight twin pregnancies in which karyotyping at 10 to 14 weeks' gestation demonstrated that at least one of the fetuses was chromosomally abnormal. Eight fetuses had trisomy 21 and two had trisomy 18. The nuchal translucency thickness was more than 2.5 mm in nine (90%) of the trisomic fetuses and in one of the chromosomally normal ones. In contrast, the crown-rump length was below the fifth percentile in only one of the fetuses with trisomy 18; all other measurements were within the normal range.