First trimester sonographic detection of chromosomal abnormalities in an unselected population

Objective To investigate the role of first trimester sonography in detecting chromosomal abnormalities in an unselected obstetric population.
Methods 2281 women (mean maternal age 30 years [range 16-47]; mean gestational age 12⁺³ weeks [range 11-14]) underwent transabdominal scanning to assess fetal structure and, if anatomical survey was considered to be incomplete (31% of cases), transvaginal sonography was also performed. Measurement of nuchal translucency was included and karyotyping performed as considered appropriate.
Results There were 16 chromosomal abnormalities; 13 (81%) were diagnosed at 11-14 weeks either because of a nuchal translucency greater than or equal to the 99th centile for gestational age (7/16; 44% [95% CI 25-63]) or due to the presence of structural abnormalities (6/16; 38% [95%CI 14.2–61.81). Seventy-five percent of cases of trisomy 21 were also diagnosed either because of having a nuchal translucency greater than or equal to the 99th centile (5/8; 63%) or due to the presence of a structural abnormality (1/8; 13%).
Conclusions A significant proportion of fetal chromosomal abnormalities can be detected by first trimester sonographic screening to assess fetal structural appearance. The sensitivity of detection can be improved by combining measurement of nuchal translucency with detailed examination of fetal anatomy.     

Increased nuchal translucency and cystic hygroma in the first trimester: prenatal diagnosis and neonatal outcome

OBJECTIVE: A prospective study of pregnancy outcome in fetuses with increased nuchal translucency above the 95th centile (group NT) or cystic hygroma (group CH) at 10 to 14 weeks of gestation was performed. PATIENTS AND METHODS: Maternal and fetal data (nuchal translucency, caryotype, pregnancy outcome) and infant follow-up of 223 fetuses with first trimester nuchal translucency thickness (183 NT and 40 CH) were analysed. RESULTS: The measurement of nuchal translucency thickness shows a significant difference between group CH and NT (7.4+/-2.9 mm compared 3.7+/-0.8 mm). Chromosomal abnormalities were present in 55% (22/40) in group CH, with 9 cases/22 (40.9%) of Turner syndrome, compared with 14.2% (26/183) in group NT with trisomy 21 in 15 cases/26 (57.7%) (P<0.05). The rate of unfavourable outcome of pregnancy (spontaneous abortion, elective termination of pregnancy, serious structural anomalies) was 80% (32/40) in group CH compared with 18% (33/183) in group NT (P<0.05). In chromosomally normal pregnancies, the rate of fetus with no visible serious structural anomalies was 44.4% (8/18) in group CH compared with 93% (146/157) in group NT (P<0.05). DISCUSSION AND CONCLUSION: Our data show ultrasonographic evaluation of the fetal nuchal translucency thickness at the first trimester is actually indispensable. Neonatal outcome and malformation rate in fetuses with increased nuchal translucency or cystic hygroma are different, even with normal karyotype.     

Measurement of nuchal translucency as a single strategy in trisomy 21 screening: should we use any other marker?

OBJECTIVE: To evaluate the role of nuchal translucency thickness as a single marker in screening for trisomy 21 at 10-16 weeks' gestation. METHODS: From December 1996 to October 2001, nuchal translucency was measured in 11,281 consecutive early second trimester fetuses referred to our unit for prenatal care and delivery. Scans were performed by eight experienced ultrasonographers, under strict methodological criteria. RESULTS: Chromosomal abnormalities were found in 118 cases (52 trisomy 21). Using nuchal translucency greater than the 95th centile as a cut-off, the overall detection rate was 71.2% with a specificity of 95.4%, and a positive predictive value of 14%. In the trisomy 21 selected group, detection rate, specificity, and positive predictive value for nuchal translucency were 92.3%, 95.4%, and 8.5%, respectively. The detection rate of trisomy 21 reached 100% when nuchal translucency was measured between 10 and 14 weeks' gestation, maintaining the same specificity. CONCLUSION: Early second trimester nuchal translucency measurement can achieve prenatal detection rates of trisomy 21 greater than 95% with a 5% false-positive rate. With a detection rate so high, the benefits of using additional markers may be less than previously considered. Although maternal age, other sonographic or Doppler markers, and maternal serum biochemistry might play a role in prenatal strategies to detect fetal chromosomal abnormalities, the high detection rate of trisomy 21 fetuses using nuchal translucency as a single parameter suggests that early nuchal translucency measurement between 10 and 14 weeks' gestation can be a simple screening strategy for this condition.     

9例多胎妊娠合并胎儿染色体异常患者的产前诊断和治疗

目的探讨多胎妊娠合并胎儿染色体异常的产前诊断方法及选择性减胎术定位方法。 方法选取2012年1月至2013年12月就诊于广州医科大学附属第三医院9例多胎妊娠合并胎儿染色体异常患者的临床资料,采用回顾性研究方法对其产前诊断方法、染色体异常情况、选择性减胎术的方法及妊娠结局进行分析。 结果9例患者中3例为三胎妊娠,6例为双胎妊娠。(1)产前诊断：①超声检查：9例患者早孕期行超声检查,均提示存在胎儿颈项透明层(nuchal translucency, NT)增厚,孕中期超声检查提示有6例患者存在胎儿结构异常,包括颈部囊肿、心脏异常、外生殖器畸形、足内翻、全身水肿等;②染色体检查：5例胎儿21-三体综合征,1例Turner综合征,1例染色体微缺失,1例染色体重复,1例双胎染色体异常。(2)治疗及妊娠结局：9例患者中7例患者行选择性减胎术治疗,1例流产,3例早产(新生儿均存在并发症),3例足月分娩(新生儿均未见异常);2例患者拒绝减胎,1例于孕中期自然流产,1例于孕35^＋周剖宫产分娩(1胎儿为21-三体综合征,另一胎儿为健康儿)。 结论多胎妊娠应注重早孕期染色体筛查,确诊宫内胎儿染色体异常的患者可在超声引导下行选择性减胎术治疗。     

First trimester umbilical artery pulsatility index in fetuses presenting enlarged nuchal translucency

The aim of this prospective study was to evaluate an umbilical artery pulsatility index (UAPI) in first trimester fetuses who present enlarged nuchal translucency (NT) measurements. UAPI was measured in 121 single fetuses with NT > or =95th centile, from 10+3 to 13+6 weeks (crown-rump length (CRL) > or =38 mm - < or =84 mm). In these fetuses there were 20 trisomy 21, and six other chromosomal abnormalities (three trisomy 18 and three monosomy X). Eighty-nine cases had normal karyotype and delivered a baby without evidence of congenital malformations. Five fetuses with normal karyotype assessed antenatally were excluded from the comparison, because of evidence of congenital malformation. A fetus with normal karyotype that was spontaneously miscarried at 14 weeks' after chorionic villus sampling was also excluded. UAPI of fetuses with enlarged NT was compared with those of 65 singleton fetuses with normal NT and normal karyotype, which were used to establish our terms of reference (5th centile, median and 95th centile). UAPI of 7/20 (35%) Down syndrome and 42/89 (47%) normal karyotype fetuses presenting enlarged NT were above the median, and respectively 2/20 (10%) and 14/89 (15.7%) were above 95th centile of normal NT and normal karyotype fetuses. No significant differences were demonstrated in the UAPI values amongst normal karyotype fetuses with normal NT or normal karyotype fetuses with an enlarged NT or trisomy 21 fetuses with an enlarged NT.     

Umbilical cord diameter at 11-14 weeks of gestation: relationship to nuchal translucency, ductus venous blood flow and chromosomal defects

OBJECTIVE: To compare the umbilical cord diameter (UCD) in euploid and aneuploid fetuses at 11-14 weeks of gestation. METHODS: In 299 fetuses at 11-14 weeks of gestation the UCD, the nuchal translucency and the a-wave of the ductus venosus were measured. Reference ranges for the UCD according to the gestational age and to the crown-rump-length (CRL) were obtained by measuring the UCD by outer-to-outer border of 244 singleton pregnancies with normal karyotype. The fetal karyotype was established by chorionic villus sampling, amniocentesis or in case of suspected chromosomal abnormalities in the newborn. Linear regression was used to determine the significance of the association between the UCD and CRL or gestational age. RESULTS: Two hundred and ninety-nine fetuses were examined. The median fetal CRL was 64.5 mm (range 45-84) and the median gestational age was 13 (range 11-14) weeks. In the chromosomally normal group the UCD significantly increased with the CRL (r=0.620; p<0.001) and the gestational age (r=0.555; p<0.001). The regression equation for the mean UCD (y) according to the gestational days (x) was: y=-0.604+0.051*x. The regression equation for the mean UCD (y) according to the CRL (x) was: y=1.962+0.029*x. There were no significant differences in the mean UCD in fetuses without and with chromosomal abnormalities. The proportion of fetuses with an UCD above the 95th centile for CRL was higher in aneuploid compared to euploid fetuses (5/14 vs. 13/285, p<0.005). In 5/14 (35.7%) fetuses with chromosomal defects the NT and the UCD were above the 95th centile, whereas none of the fetuses with normal karyotype showed this combination. The proportion of fetuses with increased UCD and abnormal DV blood flow was increased in the cases with chromosomal abnormalities (33.3 vs. 1.8%, p<0.005). CONCLUSION: Umbilical cord diameter at 11-14 weeks increases with fetal CRL. Fetuses with chromosomal abnormalities are more likely to have an UCD above the 95th centile. Therefore, sonographic evaluation of the umbilical cord during first trimester ultrasound might be of additional value in the assessment of fetuses at risk for aneuploidies.     

Abnormal first-trimester fetal nuchal translucency and Cornelia De Lange syndrome

BACKGROUND:Cornelia de Lange syndrome is a genetic disorder associated with delayed growth and characteristic facial features. There is no definitive biochemical or chromosomal marker for the prenatal diagnosis of this syndrome. We describe a case of Cornelia de Lange syndrome associated with an increased nuchal translucency in the first trimester.CASE:A large nuchal translucency was identified in a fetus during a first trimester ultrasound. Subsequent second- and third-trimester sonograms demonstrated severe fetal growth restriction, limb shortening, and abnormal facial features, despite normal fetal karyotype per chorionic villus sampling. Neonatal evaluation confirmed the diagnosis of Cornelia de Lange syndrome.CONCLUSION:Sonographic finding of an increased nuchal translucency in early pregnancy is associated with fetal aneuploidy and various structural and genetic abnormalities. Increased nuchal translucency may identify fetuses that require vigilant assessment, especially when found in association with other abnormalities.     

妊娠早期胎儿颈部透明层厚度与胎儿预后的前瞻性队列研究

目的探讨妊娠早期胎儿颈部透明层(NT)厚度与胎儿预后的关系。方法收集2015年12月至2018年12月于南京大学医学院附属鼓楼医院行妊娠早期胎儿NT厚度测量的单胎孕妇,共4958例建立前瞻性研究队列,进行妊娠早期胎儿结构超声筛查、妊娠早期血清学筛查、妊娠中期超声筛查及对新生儿出生后28 d的体格检查。根据妊娠早期超声筛查的结果,分为胎儿NT增厚(≥3.0 mm)者167例与NT厚度正常者4791例;将胎儿NT增厚的孕妇,分为胎儿单纯NT增厚者86例与NT增厚合并结构异常者81例。分析不同NT厚度胎儿的预后,并重点对单纯NT增厚与NT增厚合并结构异常胎儿的妊娠结局进行分析。妊娠早期超声筛查发现胎儿结构异常或血清学筛查结果为高风险的孕妇,经绒毛穿刺取样术行染色体微阵列分析(CMA)检测以明确产前诊断。结果(1)胎儿NT厚度正常孕妇的妊娠结局:共4791例孕妇,包括胎儿NT厚度正常且无结构异常者4726例,其中妊娠中期及产后新诊断结构异常83例,4688例活产;胎儿NT厚度正常但结构异常的孕妇65例,其中61例孕妇终止妊娠,4例活产。(2)胎儿单纯NT增厚孕妇的妊娠结局:86例孕妇中,66例(76.7%,66/86)行CMA检测,3例胎儿诊断为21三体综合征;除7例孕妇选择终止妊娠外,余79例行妊娠中期超声检查、新生儿出生后28 d体格检查、新生儿电话随访至6~21个月均未发现发育异常。(3)胎儿NT增厚合并结构异常孕妇的妊娠结局:81例孕妇中,73例(90.1%,73/81)行CMA检测,其中32例的胎儿为染色体非整倍体异常。70例选择终止妊娠,2例妊娠中期自然流产,9例活产。(4)NT增厚是否合并结构异常胎儿的产前诊断结果及预后比较:单纯NT增厚的胎儿染色体非整倍体的发生率为3.5%(3/86),合并结构异常者为39.5%(32/81),两者比较,差异有统计学意义(χ2=32.7,P<0.01);胎儿单纯NT增厚孕妇的健康新生儿存活率为91.9%(79/86),合并结构异常者为9.9%(8/81),两者比较,差异有统计学意义(χ2=112.3,P<0.01)。结论妊娠早期,超声筛查胎儿NT及结构,能提高出生缺陷的产前筛查率。单纯NT增厚胎儿的染色体非整倍体的发生率较低,新生儿健康存活率较高。     

Nuchal translucency measurement--non invasive ultrasound screening for fetal abnormalities. Part II

OBJECTIVE: There is well established association between increased nuchal translucency and chromosomal abnormality. DESIGN: To investigate a new method of screening for fetal abnormalities on the basis of maternal age and fetal nuchal translucency thickness in the first and second term of pregnancy. METHODS: A group of 650 pregnant women from the 10th week of pregnancy until childbirth has been put under examination. Nuchal translucency thickness was measured by transvaginal ultrasound examination according to Nicolaides in the first trimester of pregnancy and by transabdominal ultrasound examination between 15-19th week of pregnancy. Derived risk were then calculated. RESULTS: There were 8 chromosomal and 1 structural defects. When we used a risk of 1:250 as the cutoff to define a positive result on the screening test, the rate of detection of fetal abnormalities was 100%, with a false positive rate 0.7%. CONCLUSION: This study suggests a benefit in combining maternal age-related risk together with NT measurement in the first and second trimester of pregnancy. Such kind of test could also be helpful in twin pregnancies.     

Application of ductus venosus Doppler velocimetry for the detection of fetal aneuploidy in the first trimester of pregnancy

OBJECTIVE: To test the hypothesis the application of ductus venosus Doppler velocimetry may serve as a screening tool between 10 and 14 weeks' gestation for the detection of fetuses with chromosomal abnormalities. METHODS: 372 consecutive fetuses were studied. Based on prior study, a chromosomal abnormality was suspected when either the nuchal translucency was above the 95th centile, or there was reversed or absent flow in the ductus venosus during atrial contraction. Sensitivity, specificity, and the negative and positive predictive values were calculated. RESULTS: There were 29 chromosomally abnormal fetuses. Of these 29 fetuses, ductus venosus blood flow during atrial contraction was either absent (n = 2) or reversed (n = 25) in 93.1%. In the chromosomally normal fetuses (n = 343), only 6 (1.7%) had abnormal Doppler profiles in the ductus venosus (specificity = 98.3%, positive and negative predictive values = 81.8% and 99.4%, respectively). CONCLUSION: The Doppler waveform of the ductus venosus was at least equal to NT thickness measurement for the detection of chromosomal abnormalities.     

Submicroscopic chromosomal abnormalities in fetuses with increased nuchal translucency and normal karyotype

Objective: To investigate the submicroscopic chromosomal abnormalities in fetuses with increased nuchal translucency (NT) and normal karyotype.

Methods: Total of 296 fetuses with increased NT (≥3.0?mm) were tested by conventional karyotyping. When cytogenetic analysis showed normal chromosome, the pregnancies were then consulted for array-comparative genomic hybridization (CGH) analysis and received subsequent morphology scan between 20 and 24 weeks gestation. Submicroscopic chromosomal abnormalities were assessed and compared between the fetuses with and without structural defects.

Results: Chromosomal abnormality was identified in 19.9% (59/296) fetuses. Two hundred and twenty samples were tested by array CGH. Submicroscopic chromosomal abnormalities were detected in 9.1% (20/220) fetuses. For the fetuses with abnormal morphology scan, the detection rate of submicroscopic chromosomal abnormalities was higher than those with normal morphology scan (26.9% versus 6.7%, p?Conclusions: Submicroscopic chromosomal abnormalities should be accessed when the fetus was found to be with increased NT and normal karyotype, especially when the structural defects were found at second or third trimester.     

Increased nuchal translucency at 11-14 weeks of gestation in congenital heart disease, genetic syndromes and adverse pregnancy outcome

Nuchal translucency (NT) measurement between 11-14 weeks of gestation is an'effective method of ultrasound screening for chromosomal fetal anomalies, congenital heart disease, some other structural abnormalities, rare genetic syndromes, skeletal dysplasia and adverse pregnancy outcome (spontaneous abortion and intrauterine fetal demise). The aim of the present study is to assess the prognostic value of increased first trimester NT in fetuses with normal karyotype in relation to pregnancy outcome.     

The use of nuchal translucency measurement and second trimester biochemical markers in screening for Down's Syndrome

Objective To assess the effectiveness of antenatal screening for trisomy 21 by first trimester sonography followed by second trimester biochemical screening.
Design Retrospective five-year review.
Setting Maternity unit of a university hospital.
Population An unselected group of 7447 pregnant women who had a first trimester scan and nuchal translucency measurement in our unit after January 1995 and had an estimated date of delivery before 1 January 2000. 11.9% were ≥ 37 years old. A subgroup (   n =4864  ) also had second trimester biochemical testing by alpha-fetoprotein and free β-human chorionic gonadotrophin.
Main outcome measures Prenatal and postnatal diagnosis of trisomy 21.
Results There were 23 fetuses affected with trisomy 21. The overall prenatal detection rate was 87% (20/23; 95% CI 66% to 97%) and we performed invasive procedures in 8.5% of our population. First trimester sonography identified 74% (95% CI 51.6% to 89.8%) of affected fetuses. Second trimester biochemical screening detected half of the fetuses with trisomy 21 which were missed by first trimester screening, increasing the sensitivity to 90.5% (19/21; 95% CI 69.6% to 98.8%) for an invasive procedure rate of 4.2% performed in screened positive women. However, the positive predictive value of the biochemical test was very low (0.5%). In screen negative women, karyotyping for advanced maternal age did not detect any affected fetuses.
Conclusion First trimester nuchal translucency measurement is an effective screening test for the prenatal detection of fetuses with Down's Syndrome. Although the measurement of biochemical markers in the second trimester can detect additional affected fetuses this may be outweighed by the delay in diagnosis, the extra visits and cost so that the right time for biochemical screening is most likely to be in the first trimester.     

Single umbilical artery and its siding in the second trimester of pregnancy: relation to chromosomal defects

OBJECTIVES: To determine the possible association between single umbilical artery (SUA) in the second trimester of pregnancy and the incidence of chromosomal abnormalities. To determine whether the presence of chromosomal defects in fetuses with SUA is related to the side of the missing artery. METHODS: Color flow imaging of the fetal pelvis was used to determine the number of umbilical arteries in 2147 fetuses immediately before amniocentesis for karyotyping in the second trimester of pregnancy. RESULTS: SUA was diagnosed in 102/2147 (4.8%) cases. The left umbilical artery was absent in 60/102 (58.8%) fetuses, compared with the 42/102 (41.2%) for the right artery. The rate of chromosome abnormalities was significantly higher among fetuses with SUA than among those with 2 umbilical arteries (19/102 or 18.6% versus 109/2045 or 5.3%; OR = 4.1, 95% CI 2.3-7.1, p < 0.0001). Among fetuses with SUA, there was no significant difference in the rate of chromosome abnormalities between those with absence of the left versus the right artery (11/60 or 18.3% versus 8/42 or 19.0%, p = 0.93). There was an SUA in 5/39 (12.8%) cases with trisomy 21, 8/16 (50%) with trisomy 18, 1/4 (25%) with trisomy 13 and 5/69 (7.2%) with other chromosomal defects. There were no chromosome abnormalities in fetuses where a single umbilical artery was an isolated sonographic finding. All fetuses with SUA and chromosomal defects had associated abnormalities detected by ultrasound. CONCLUSION: A single umbilical artery (SUA) in the second trimester of pregnancy has a high association with trisomy 18, 13, 21 and other chromosomal defects, but all chromosomally abnormal fetuses had associated malformations detected by ultrasound. The absence of the left artery is more frequent than the absence of the right artery. The association with chromosomal abnormalities seems to be equal on each side.     

Relation between increased fetal nuchal translucency thickness and chromosomal defects

OBJECTIVE: To examine the prevalence and distribution of all chromosomal defects in fetuses with increased nuchal translucency thickness. METHODS: Assessment of risk for trisomy 21 was carried out by a combination of maternal age and fetal nuchal translucency thickness at 11-13 + 6 weeks. A search of the database was made to identify, first, all singleton pregnancies in which fetal karyotyping was carried out and, second, the cases where the fetal nuchal translucency was equal to or above the 95th centile for fetal crown-rump length. The prevalence and distribution of chromosomal defects were determined for each nuchal translucency category: between the 95th centile for crown-rump length and 3.4 mm, 3.5-4.4 mm, 4.5-5.4 mm, 5.5-6.4 mm, 6.5-7.4 mm, 7.5-8.4 mm, 8.5-9.4 mm, 9.5-10.4 mm, 10.5-11.4 mm, and 11.5 mm or more. RESULTS: The search identified 11,315 pregnancies. The median maternal age was 34.5 (range 15-50) years, and the median fetal crown-rump length was 64 (range 45-84) mm. The fetal karyotype was abnormal in 2,168 (19.2%) pregnancies, and the incidence of chromosomal defects increased with nuchal translucency thickness from approximately 7% for those with nuchal translucency between the 95th centile for crown-rump length and 3.4 mm to 75% for nuchal translucency of 8.5 mm or more. In the majority of fetuses with trisomy 21, the nuchal translucency thickness was less then 4.5 mm, whereas in the majority of fetuses with trisomies 13 or 18 it was 4.5-8.4 mm, and in those with Turner syndrome it was 8.5 mm or more. CONCLUSION: In fetuses with increased nuchal translucency, approximately one half of the chromosomally abnormal group is affected by defects other than trisomy 21. The distribution of nuchal translucency is different for each type of chromosomal defect. LEVEL OF EVIDENCE: II-3.     

Nuchal translucency and other first-trimester sonographic markers of chromosomal abnormalities

There is extensive evidence that effective screening for major chromosomal abnormalities can be provided in the first trimester of pregnancy. Prospective studies in a total of 200,868 pregnancies, including 871 fetuses with trisomy 21, have demonstrated that increased nuchal translucency can identify 76.8% of fetuses with trisomy 21, which represents a false-positive rate of 4.2%. When fetal nuchal translucency was combined with maternal serum free-beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A in prospective studies in a total of 44,613 pregnancies, including 215 fetuses with trisomy 21, the detection rate was 87.0% for a false-positive rate of 5.0%. Studies from specialist centers with 15,822 pregnancies, which included 397 fetuses with trisomy 21, have demonstrated that the absence of the nasal bone can identify 69.0% of trisomy 21 fetuses, which represents a false-positive rate of 1.4%. It has been estimated that first-trimester screening by a combination of sonography and maternal serum testing can identify 97% of trisomy 21 fetuses, which represents a false-positive rate of 5%, or that the detection rate can be 91%, which represents a false-positive rate of 0.5%. In addition to increased nuchal translucency, important sonographic markers for chromosomal abnormalities, include fetal growth restriction, tachycardia, abnormal flow in the ductus venosus, megacystis, exomphalos and single umbilical artery. Most pregnant women prefer screening in the first, rather than in the second, trimester. As with all aspects of good clinical practice, those care givers who perform first-trimester screening should be trained appropriately, and their results should be subjected to external quality assurance.     

胎儿颈项透明层增厚和静脉导管血流频谱异常与胎儿染色体异常的关系

目的探讨胎儿颈项透明层(nuchal translucency, NT)超声检查在早孕期胎儿筛查中的应用价值。 方法收集104例于广州市妇女儿童医疗中心诊断NT增厚的孕妇的染色体核型分析资料,回顾性分析胎儿NT增厚、静脉导管血流频谱异常与胎儿染色体异常的关系。 结果(1)9980例孕妇中,NT异常增厚的胎儿共104例,占1.0%,颈项透明层厚度为(3.7±1.2)mm;(2)104例NT异常增厚的胎儿中,有28例胎儿染色体核型异常,包括染色体数目异常22例,结构异常6例,其中前3位为21-三体综合征、18-三体综合征和47,XXX;(3)随着NT厚度的增加,染色体异常的检出率相应增加;(4)NT增厚及静脉导管血流频谱正常预测染色体异常的阳性预测值是20.93%,NT增厚及静脉导管血流频谱异常的阳性预测值是55.56%,其差异具有统计学意义( χ²＝7.07,P<0.01)。 结论在早孕期进行胎儿NT超声检查,NT增厚及静脉导管血流频谱异常联合筛查更能有效筛查出染色体核型异常的高危胎儿。     

Detection of fetal structural abnormalities by an 11-14-week ultrasound dating scan in an unselected Swedish population

BACKGROUND: To determine the detection rate of fetal structural abnormalities by a routine 11-14-week ultrasound scan for dating in an unselected pregnant population. METHODS: A prospective observational cohort study of 2,708 unselected pregnant women attending an abdominal ultrasound examination at 11-14 weeks gestation. The number of major fetal structural abnormalities diagnosed after birth was obtained from a computerized database at the same unit. RESULTS: Out of 2,708 pregnant women, 89 (3.3%) were found to have a missed abortion at the time of the ultrasound scan and 33 (1.2%) were diagnosed as twins. Thirteen major structural abnormalities were detected, three cases of anencephaly (one case also had a spina bifida), one case with hydranencephaly, one fetus with Dandy-Walker syndrome, two cases with gastroschisis, one case with a bilateral hydronephrosis, one case with a generalized hydrops, one fetus with multiple malformations, and three cystic hygromas. An additional 19 major structural defects were detected at birth. Four cases of neural tube defects and nine fetuses with congenital heart defects were diagnosed. The antenatal ultrasound detection rate was 40.6% (13/32). Nine patients had a nuchal translucency greater than 3.0 mm (excluding cystic hygromas); two of them had chromosomal abnormalities (trisomy 21 and trisomy 18). CONCLUSIONS: Fetal structural abnormalities were detected in 41% (95%CI = 24-59) of the cases in an unselected pregnant population at a routine 11-14-week ultrasound scan for dating purpose. Two out of nine fetuses with a nuchal translucency greater than 3.0 mm had a chromosomal abnormality.     

Are placental lakes of any clinical significance?

The aim of this study was to determine prospectively whether an association exists between the finding of placental lakes at the 20 week scan and an increased risk of uteroplacental complications or a poor pregnancy outcome. We studied the placental appearances in 1,198 consecutive second trimester ultrasound scans performed for routine foetal abnormality screening at our institution. The placental thickness was measured at its widest diameter in the sagittal plane and the presence or absence of placental lakes was recorded. The birth weight in each case was plotted against the centile charts in use at the hospital and recorded. Specific outcome measures included foetal growth restriction (IUGR) with a birth weight below the 5th centile, pre-eclampsia, placental abruption, and perinatal deaths. Placental lakes were seen in 17.8 per cent of the scans. There was no significant association with either maternal socio-demographic factors or perinatal mortality (OR 0.94, 95 per cent CI 0.35-2.51). No association was seen with maternal cigarette smoking (OR 1.07, 95 per cent CI 0.75-1.52), a birth weight below the 5th centile (OR 0.68, 95 per cent CI 0.39-1.18), the development of pregnancy induced hypertension (OR 0.68, 95 per cent CI 0.35-1.32), severe pre-eclampsia (OR 0.72, 95 per cent CI 0.21-2.50), or placental abruption (OR 1.79, 95 per cent CI 0.46-6.99). A finding of placental lakes was six times more likely with a thick placenta >3 cm at 20 weeks gestation (OR 6.30, 95 per cent CI 4.39 to 9.05). A finding of placental lakes during the second trimester ultrasound scan does not appear to be associated with uteroplacental complications or an adverse pregnancy outcome. The lesions are more prevalent with increasing placental thickness.     

Screening for adverse pregnancy outcome by ductus venosus Doppler at 11-13+6 weeks of gestation

OBJECTIVE: To estimate the independent contribution of abnormal flow in the ductus venosus at 11 to 13+6 weeks of gestation in the prediction of major fetal abnormalities and fetal death. METHODS: This was a prospective assessment of singleton pregnancies by maternal history, serum free beta-hCG, pregnancy-associated plasma protein A (PAPP-A), fetal nuchal translucency thickness, and ductus venosus Doppler. The patients were subdivided into five groups: normal outcome (n=10,120), miscarriage or fetal death (n=185), abnormal karyotype (n=95), and major cardiac (n=20) or noncardiac defect (n=70). Regression analysis was performed to determine the significance of the contribution to adverse outcome of reversed a-wave in the ductus venosus, maternal characteristics, fetal delta nuchal translucency, maternal serum log PAPP-A multiples of the median, and log free beta-hCG multiples of the median. RESULTS: The prevalence of reversed a-wave was significantly higher in the groups with miscarriage or fetal death (10.8%), abnormal karyotype (62.1%), and fetal cardiac defect (25.0%) than in the normal outcome group (3.7%), but not noncardiac defect (4.3%). An adverse outcome was observed in 2.7% of the fetuses with nuchal translucency at or below the 95th centile (in 2.6% of those with normal a-wave and in 7.0% of those with reversed a-wave) and in 19.3% of the fetuses with nuchal translucency above the 95th centile (in 8.9% of those with normal a-wave and in 70.9% of those with reversed a-wave). CONCLUSION: Reversed a-wave is associated with increased risk for chromosomal abnormalities, cardiac defects, and fetal death. However, in about 80% of cases with reversed a-wave, the pregnancy outcome is normal.