Sonographic features of trisomy 18 at midpregnancy

OBJECTIVE: To evaluate the sonographic characteristics of the fetuses with trisomy 18 at 16-22 weeks of gestation. METHODS: The subjects were recruited from pregnant women undergoing prenatal sonographic examinations at 16-22 weeks of gestation and subsequently proven to be trisomy 18. The results of ultrasound findings were retrospectively reviewed in 25 cases with chromosomes which were confirmed as trisomy 18. RESULTS: All cases had at least one abnormal sonographic finding. There was only one case that had no structural abnormality, but fetal growth restriction was documented. The common sonographic findings included fetal growth restriction, choroid plexus cysts, cardiac anomalies, clenched hand, omphalocele and cleft lip. Fetal growth restriction was the most common finding demonstrated in nearly half of all cases. Other less common findings were diaphragmatic hernia, abnormal head shape, polyhydramnios, single umbilical artery. CONCLUSION: Nearly all fetuses with trisomy 18 had characteristic sonographic patterns of abnormalities demonstrated at midpregnancy. Detailed ultrasound at midpregnancy could effectively screen fetuses with trisomy 18 for further genetic testing.     

中晚孕期18-三体综合征胎儿的超声特征

目的:研究中晚孕期18-三体综合征胎儿超声影像的变化。方法:回顾分析经羊膜腔穿刺、脐血管穿刺胎儿染色体分析确诊为18-三体的胎儿24例的临床资料和超声影像特征。结果:24例18-三体胎儿中,22例超声影像有变化,占全部病例的91.7%;最常见的超声变化是心脏畸形,共15例,占62.5%;其它常见的异常有脉络膜囊肿、脐带异常、肢体异常、宫内生长迟缓、脑室扩大、小脑延髓池扩大等;还可见颅骨变形、颜面裂、颈项皮肤增厚、消化道闭锁、腹壁缺损、膈疝、肾盂轻度积水、羊水过多等。结论:超过90%的18-三体胎儿中晚孕期可发现超声影像改变,中晚孕期胎儿超声检查是产前筛查18-三体胎儿的有效手段。     

The prenatal diagnosis of Pierre-Robin sequence.

The purpose of this study was to evaluate the spectrum of prenatal sonographic and chromosomal findings, associated anomalies and perinatal and neonatal outcomes in cases with Pierre-Robin sequence. All cases (20) with Pierre Robin sequence, who were born at China Medical College Hospital between 1990 and 1997, were included and analysed in this series. 12 pregnancies (60 per cent) were complicated by polyhydramnios and 9 (45 per cent) were combined with cleft palate. Four cases (20 per cent) with cardiac anomalies were also observed. Two fetuses (10 per cent) had abnormal karyotyping (one trisomy 21, one trisomy 18). All fetuses were delivered at or near term. Male deviation was observed in cases with isolated Pierre-Robin sequence or combined mild anomalies (male female ratio: 13:3). Two neonatal mortalities and three with mental retardation were observed. This investigation provides a basis for counselling patients with fetal micrognathia or neonatal Pierre-Robin sequence. The main prenatal sonographic findings of Pierre-Robin sequence are micrognathia, polyhydramnios and cleft palate. In cases of polyhydramnios, sonographic examination of the facial profile and palate are recommended. After the finding of polyhydramnios, micrognathia, and even cleft palate, clinicians should be aware of the possibility of neonatal Pierre-Robin sequence. Cardiac evaluation and karyotyping is also recommended.     

Prenatal diagnosis of dilated cava septi pellucidi et vergae: associated anomalies, differential diagnosis, and pregnancy outcome.

OBJECTIVE: To study the significance of dilated cava septi pellucidi et vergae diagnosed prenatally using ultrasonography. METHODS: Sonographic examinations were performed on 11,200 pregnant women. Transabdominal sonographic examinations were done at 24 weeks or later on 3150 pregnant women and transvaginal sonographic examinations were done between 13-17 weeks on 8050 pregnant women. RESULTS: Eight cases of enlarged cava septi pellucidi et vergae were diagnosed prenatally during the second trimester of pregnancy by transvaginal sonography. In only one fetus did dilatation of cava septi pellucidi et vergae disappear during the third trimester. Associated anomalies, three of which were hydrocephalus, were observed in five fetuses. One fetus had chromosomal translocation 11/22 and one was growth-retarded. Pregnancy was terminated in four cases because of associated fetal anomalies or abnormal chromosomal analysis. One of four neonates died of unexplained metabolic acidosis. One neonate demonstrated cava septi pellucidi et vergae communication with the third ventricle and another had mild hydrocephalus on sonographic examination after birth. The three surviving fetuses had normal development during the first months of life. CONCLUSIONS: When dilated cava septi pellucidi et vergae are diagnosed prenatally, attention should be paid to the possible presence of associated fetal malformations. When a cyst of cava septi pellucidi et vergae is the only abnormal finding observed, termination of pregnancy is not justified.     

18-三体综合征胎儿超声声像特征分析

目的分析18-三体综合征胎儿超声声像特征,以期早期诊断与处理。方法回顾分析经染色体核型分析确诊的18-三体儿12例超声检查的资料。结果全部18-三体儿存在二个或以上异常超声声像表现。其中,胎儿生长受限、羊水过多表现率最高,各为58.3%;其次是心脏畸形,50.0%;再其次是脉络丛囊肿、单脐动脉、脑发育不全、上肢发育异常。在〈28周的胎儿中,超声异常的表现率最高的是心脏畸形、脉络丛囊肿,各为66.7%,其次是胎儿生长受限、羊水过多,各为50.0%。胎儿生长受限主要表现为股骨长度发育落后于正常。结论超声检查是产前筛查18-三体儿的有效手段。     

A characteristic cluster of fetal sonographic markers that are predictive of fetal Turner syndrome in early pregnancy

OBJECTIVE: The purpose of this study was to describe a characteristic cluster of sonographic features of fetuses with Turner syndrome in early pregnancy. STUDY DESIGN: A targeted transvaginal ultrasound examination of all fetal organs was performed for 40123 consecutive pregnant women at 14 to 16 weeks of gestation. Both low- and high-risk pregnancies were included. Fetal karyotyping was performed in 9348 cases. The main indications were major fetal anomalies, advanced maternal age, abnormal biochemical markers, maternal anxiety, and request. RESULTS: Turner syndrome was detected in 13 fetuses (0.03%, 1/3086 early pregnancies). Huge septated cystic hygroma, severe subcutaneous edema, and hydrops were observed in all cases. A short femur was detected in 12 of 13 fetuses. A narrow aortic arch was visualized in all 8 fetuses who were scanned after 1995, when scanning of the aortic arch became mandatory in our institution. Four other fetuses had three or four of the five markers, 2 of the fetuses had trisomy 21, 1 fetus was normal, and one case of missed abortion occurred without a karyotype. CONCLUSION: A reliable diagnosis of Turner syndrome by sonographic means is possible in early pregnancy.     

Pseudocyst of the umbilical cord: prenatal sonographic appearance and clinical significance

OBJECTIVE: To assess the clinical significance of umbilical cord pseudocysts detected prenatally by sonography. METHODS: The prenatal sonographic findings, karyotype, and perinatal outcome in 13 fetuses with umbilical cord pseudocysts were reviewed retrospectively. RESULTS: Umbilical cord pseudocysts were diagnosed at a median gestation of 27 weeks (range 15-37). Pseudocysts were single in eight cases with cyst diameters ranging from 20 to 50 mm, and double in one case. In the remaining four cases, multiple small cystic masses measuring less than 8 mm were identified. Additional sonographic findings were noted in 11 cases; ten of these fetuses had prenatal karyotyping, which showed trisomy 18 in five cases, trisomy 13 in one case, and a 46,XX, inv ins(18;21) complement in one case. Among the seven chromosomally abnormal fetuses, umbilical cord pseudocysts were multiple in four fetuses and single in three. All chromosomally abnormal fetuses and two euploid fetuses with associated structural defects died in utero or in the neonatal period. There were no perinatal complications in either of the fetuses with isolated pseudocysts. CONCLUSION: The prenatal sonographic appearance of umbilical cord pseudocysts varied widely. These umbilical cord cystic masses were associated strongly with chromosomal disorders and structural defects, regardless of their sonographic appearance in utero.     

9例18三体综合征胎儿的产前诊断

目的探讨利用孕妇血清筛查和胎儿超声筛查进行18三体综合征胎儿产前诊断的有效性。方法对36例首诊主诉为产前筛查胎儿18三体高危、92例首诊主诉为胎儿超声有异常发现的孕18~32周孕妇共128例，进行羊膜腔穿刺羊水细胞培养、或脐血管穿刺脐血细胞培养染色体分析。结果128例胎儿核型中，9例为18三体综合征，2例为其它染色体异常，染色体异常发现率为8．59％（11／128）。首诊主诉为18三体高危发现18三体4例，异常发现率11．11％（4／36）；首诊主诉胎儿超声异常发现18三体5例，其它染色体异常2例，异常发现率7．61％，其中2例18三体合并有筛查高危和超声异常。结论孕妇血清生化指标筛查结合胎儿超声检查是产前检出18三体胎儿的有效筛查手段。     

Choroid plexus cysts in the fetus: a benign anatomic variant or pathologic entity? Report of 41 cases and review of the literature

During a 22-month period, 6288 women undergoing prenatal sonographic studies in the second and third trimesters were evaluated prospectively to determine the incidence of choroid plexus cysts in the fetus, to follow the natural course of these cysts in intrauterine life, and to determine the association of chromosomal and anatomic anomalies in these fetuses. We diagnosed choroid plexus cysts in 41 fetuses, an incidence of 0.65%. Unilateral and bilateral cysts were equally frequent, and in most cases diagnosed by 21 weeks' gestation. On follow-up scans, the cysts had completely disappeared by 23-24 weeks in 80% of the cases, and by 28 weeks in another 10%. Once resolved, the cysts did not recur, and a normal sonogram in the late second trimester predicted normal scans in late pregnancy and in the neonate. One fetus had a chromosomal abnormality (trisomy 18). Associated anatomic anomalies were detected in three fetuses, including the one with trisomy 18. We believe that in the great majority of cases, fetal choroid plexus cysts are benign transient variants of normal intracranial anatomy. It is, however, important to conduct a careful sonographic search for associated anomalies. Chromosomal studies are strongly recommended whenever associated anatomic abnormalities are detected and when the choroid plexus cysts are large, bilateral, and persistent beyond 20-22 weeks' gestation.     

The utility of detailed first trimester ultrasound examination in abnormal fetal nuchal translucency

OBJECTIVE: To determine the value of a first trimester fetal ultrasound examination in cases of an increased nuchal translucency (NT). METHOD: A detailed fetal ultrasound examination was performed within 4 days of a detection of a first trimester increased NT. RESULTS: As many as 23 fetuses were evaluated. Severe anomalies were detected in eight and mild anomalies were detected in six fetuses. Two fetuses had trisomy 13, one had trisomy 21, and 16 fetuses had a normal karyotype. A chromosomal analysis was not available in four fetuses with major anomalies due to parental decision. In one fetus, craniosynostosis was detected only at 24 weeks' gestation. CONCLUSIONS: The current study shows that a first trimester targeted scan of fetuses with an increased NT in an experienced center can shorten the parental decision-making process and spare parents a prolonged period of diagnostic uncertainty and anxiety, particularly when a structural anomaly is clearly diagnosed in the first trimester.     

Prenatal sonographic findings in 207 fetuses with trisomy 21

OBJECTIVE: The objective was to evaluate the contribution of second trimester ultrasound examination to the prenatal diagnosis of trisomy 21 in 207 fetuses with this aneuploidy. The type and frequency of abnormal sonographic findings were determined. Possible multiple malformation patterns, characteristic of trisomy 21 were sought. STUDY DESIGN: Singleton fetuses that had prenatal sonography during the second trimester, then underwent cytogenetic evaluation in our institution, made up the study population. The sonographic findings of 207 fetuses with trisomy 21 were analyzed. RESULTS: Between 1990 and 2004, fetal karyotyping was performed in 22,150 patients for different indications. An abnormal karyotype was diagnosed in 514 cases (2.3%); among them 207 fetuses with trisomy 21 were detected (40.3%). Abnormal sonography was seen in 63.8% of the cases. Structural anomalies were detected in 28.5% of the trisomy 21 fetuses, among them cardiac defects (15.9%), central nervous system anomalies (14.5%), and cystic hygromas (6.8%) were the most common. Of the minor markers, increased nuchal translucency (28%), pyelectasis (20.3%), and shorter extremities (8.7%) were common findings. CONCLUSIONS: Appropriate diagnosis of structural anomalies, looking for relatively easily detectable minor markers and incorporating fetal echocardiography into the second trimester sonographic protocol, may increase the contribution of mid-trimester ultrasound examination to diagnosing trisomy 21.     

Cardiac and extra-cardiac anomalies as indicators for trisomies 13 and 18: a prenatal ultrasound study

The purpose of the present study was to establish sonographic markers for prenatal diagnosis of trisomies 13 and 18. Retrospective analysis of sonographic morphology was therefore carried out in seven fetuses with trisomy 13, and 16 fetuses with trisomy 18. Gestational age ranged between 17 and 39 weeks (median 28 weeks). Polyhydramnios and symmetrical growth retardation were present in 14 of 23 fetuses. A cardiac anomaly was diagnosed in all 23 fetuses, the majority representing a ventricular septal defect (n = 8) or double outlet right ventricle (n = 8). Extra-cardiac anomalies were characterized by a high incidence of limb deformities (polydactyly, clenched hands, club feet; n = 15) and omphalocele (n = 7). We conclude that the combined appearance of cardiac and extra-cardiac anomalies should prompt fetal karyotyping. Cardiac anomalies in combination with fetal limb deformities and omphalocele are suspicious for trisomies 13 and 18.     

Ultrasound findings in trisomy 22

We sought to identify the characteristic sonographic findings of fetal trisomy 22 by performing a retrospective review of nine cases of fetal trisomy 22. All cases of chromosomal mosaicism were excluded, as were first-trimester losses. Indications for sonography, gestational age, and sonographically detected fetal anomalies were analyzed. The majority of patients were referred for advanced maternal age or abnormal ultrasound findings on screening exam. Oligohydramnios was the most common sonographic finding, present in 55% of affected fetuses. Intrauterine growth restriction and increased nuchal thickness were slightly less frequent.     

The timing of demise in fetuses with trisomy 21 and trisomy 18

OBJECTIVE: Women with chromosomally abnormal fetuses often choose to continue their pregnancy. However, though they may search for specific details whether their fetus will survive, not much information is available. We sought to determine if there was a pattern for timing of demise and to determine if demise was more likely to occur before viability in fetuses with amniocentesis confirmed trisomy 18 or 21. METHODS: From the California Expanded AFP screening program, 1813 women were identified to have a fetus with trisomy 18 or 21. Of these, 392 women with trisomy 21 and 106 with trisomy 18 continued the pregnancy. Pregnancies ending in fetal demise were analyzed for gestational age at demise. RESULTS: Of the trisomy 21 fetuses, 40 (10.2%) demised and of the trisomy 18 fetuses, 34 (32.1%) demised. The mean gestational age at time of fetal demise was 28.9+/-1.3 weeks SE for trisomy 21 and 32.1+/-1.2 weeks SE for trisomy 18 (p=0.09). There was no clustering of losses as losses were uniformly distributed throughout gestation after 24 weeks. A slightly larger proportion of T-21 (37.1%) losses occurred before viability (24 weeks) compared to those with T-18 (14.8%) (p=0.05). CONCLUSION: It appears that after 24 weeks' gestation, there is no specific time for fetal demise in fetuses affected by trisomy 21 or 18. There may be an association between trisomy 21 and stillbirth prior to viability. This information may be helpful in counseling those patients found to have a chromosomally abnormal fetus who choose to continue their pregnancy.     

Sensitivity of prenatal ultrasound for detection of trisomy 18

Objectives: To evaluate the sensitivity of prenatal ultrasound (US) for trisomy (T18) diagnosis and describe US findings in a large tertiary care institution in the USA.

Materials and methods: This was a retrospective cohort of all T18 cases diagnosed at our institution from October 2004 to October 2014 based on prenatal or postnatal genetic diagnostic testing. We included all women with a fetus affected by T18 who had a comprehensive US by a maternal–fetal medicine specialist performed at our institution. US findings were reviewed, classified by organ system, and categorized as an anomaly or soft marker. Chi-square or t-test was used for statistical analysis.

Results: We included 128 cases of T18 with confirmed cytogenetic analysis ?110 (86%) of which were diagnosed prenatally or suspected by cell-free DNA and confirmed postnatally, and 18 of which underwent neonatal blood sampling alone. One hundred and twenty-one (95%) had at least one abnormal US finding. Anomalies were more frequently identified on US at ≥20 weeks as compared with <20 weeks (93% versus 76%; p?=?.004). The mean number of findings detected per fetus was 5.1?±?3.0. Fetuses diagnosed by postnatal sampling alone had a similar number of US exams performed and number of abnormal findings compared to those diagnosed prenatally.

Conclusion: Ninety-five percent of fetuses with T18 had at least one abnormal US finding. This sensitivity of is higher than reported in most prior studies, but is not 100%, and should be considered when counseling women regarding prenatal diagnosis of T18.

Rationale: Historical detection rates for abnormal sonographic findings in trisomy 18 fetuses range from 70% to 100%. These studies are limited by small sample sizes. This is a contemporary study of ultrasound findings in a large group of women with confirmed trisomy 18 by prenatal or postnatal genetic diagnosis. We provide expansive detail on soft markers and anomalies broken down by organ-system and gestational age.     

Sacrococcygeal teratoma in a fetus with prenatally diagnosed partial trisomy 10q (10q24.3-->qter) and partial monosomy 17p (p13.3-->pter)

OBJECTIVE: Clinical features of the distal 10q trisomy syndrome consist of mental retardation, facial dysmorphism and renal and cardiac anomalies. The presence of a sacrococcygeal teratoma (SCT) in a fetus with distal 10q trisomy has not been reported yet. METHODS: A 33-year-old, G5, P2 woman with a singleton pregnancy was referred to our clinic at 24 weeks of gestation for further evaluation of a fetal sacral exophytic mass. Detailed fetal sonographic examination together with chromosomal analysis by amniocentesis was performed. RESULTS: The scan revealed a large SCT together with a persistent right umbilical vein, cardiomegaly, bilateral mild hydronephrosis and intrauterine growth retardation. The fetal karyotype showed distal 10q trisomy (10q24.3-->qter) distal monosomy 17 (p13-->pter). The fetus died after a preterm delivery at 28 weeks of gestation. Postnatal examination confirmed the prenatal findings and added the typical facial features of this syndrome, which consisted of prominent forehead, small nose with depressed nasal bridge, micrognathia and bow-shaped mouth. CONCLUSION: This case provides further evidence of a possible association between chromosomal aberrations in SCTs.     

Agenesis of the ductus venosus that is associated with extrahepatic umbilical vein drainage: prenatal features and clinical outcome

OBJECTIVE: We sought to study the clinical and ultrasonographic findings and outcomes of fetuses with ductus venosus agenesis as the result of extrahepatic umbilical vein drainage. STUDY DESIGN: This was an observational study of 12 fetuses who were diagnosed with these anomalies between 1995 and 2001. RESULTS: The umbilical vein drained either directly into the right atrium (n = 7 fetuses), the inferior vena cava (n = 3 fetuses), or the iliac vein (n = 2 fetuses). Combined cardiac output (n = 8 fetuses) was nearly 2-fold increased to 891 +/- 210 mL/kg per minute. Other relevant findings were (1) considerable umbilical vein enlargement (12/12 cases; range, 8-13 mm) with an accelerated (peak, 0.53 +/- 0.1 m/s), (2) pulsatile Doppler flow pattern within its intra-abdominal course, (3) cardiomegaly (12/12 fetuses), (4) secundum atrial septal defects (5/12 fetuses), (5) extracardiac anomalies (5/12 fetuses), (6) polyhydramnios (4/12 fetuses), and (7) progressive heart failure (3/12 fetuses). Two fetuses died: 1 death was unexplained at 29 weeks of gestation; the other death from hydrops occurred after delivery at 32 weeks of gestation. So far, none of the survivors have had other long-term sequelae that were related to ductus venosus agenesis. CONCLUSION: Careful assessment of the umbilical venous return and the ductus venosus should be part of the routine evaluation of every fetus with heart failure and polyhydramnios.     

Transvaginal sonography-detection of findings suggestive of fetal chromosomal anomalies in the first and early second trimesters.

Over a 4-year period, 14 dyskaryotic fetuses were diagnosed by amniocentesis, performed after early detection of malformations using transvaginal sonography (TVS). These 14 dyskaryotic fetuses were detected out of 4878 sonographic screenings performed by TVS between 9 and 16 weeks' gestation. Twenty-eight per cent of the referrals were at high risk and 72 per cent were at low risk for fetal malformations. Two hundred and twenty-nine fetuses (4.7 per cent) of the screened population had 265 anomalies, 39 per cent of them being transient. In 7 of the 14 dyskaryotic fetuses (50 per cent), the sonographically detected anomalies were transient, being undetected by follow-up sonographic screenings at later gestational ages (greater than or equal to 18 weeks). Postponing the first sonographic scan aimed at malformation detection to a later gestational age may lead to transient anomalies and their associated dyskaryosis being missed.     

Are choroid plexus cysts an indication for second-trimester amniocentesis?

Previous series that described fetuses with choroid plexus cysts have been too small to determine whether there is an association with trisomy 18 sufficiently high to warrant amniocentesis. To address this issue, we studied the incidence of choroid plexus cysts and other ultrasonographic abnormalities in 26 consecutive fetuses (13.5 to 36 weeks' gestation) with trisomy 18. Twenty of these 26 fetuses had major sonographic anomalies suggestive of aneuploidy. Seventeen of these 26 fetuses were 15 to 20 weeks and 5 of 17 (30%) had choroid plexus cysts. Six of our total 26 affected fetuses had no sonographic anomalies and therefore, on the basis of our data, 30% of these (1.8 fetuses) with trisomy 18 would have choroid plexus cysts without other findings. The incidence of choroid plexus cysts in all second-trimester fetuses (including normal fetuses and those with trisomy 18) is reportedly 1%. Given the known incidence of trisomy 18 (3/10,000), we calculated a total presumptive sample of 86,667 patients to yield our 26 fetuses with trisomy 18. Our hypothetical sample has 86,641 (86,667 - 26) fetuses without trisomy 18,858 of which would have choroid plexus cysts. Thus there would be one fetus with trisomy 18 for every 477 normal fetuses with choroid plexus cysts with no other defect seen. If amniocentesis were done to seek trisomy 18 in all second-trimester fetuses with choroid plexus cysts, two normal fetuses would be lost for every one with trisomy 18 identified.     

First-trimester nuchal translucency measurement and echocardiography at 16 to 18 weeks of gestation in prenatal detection for trisomy 18

BACKGROUND: Trisomy 18, the second most common autosomal trisomy, has the highest incidence of congenital heart disease of all chromosomal abnormalities. This study assessed the use of nuchal translucency (NT) measurement and fetal echocardiography at 16 to 18 weeks of gestation in prenatal detection for trisomy 18. METHODS: Screening for chromosomal aneuploidy using fetal NT measurement was performed at 10 to 14 weeks of gestation. Detailed fetal echocardiography was performed at 16 to 18 weeks of gestation immediately before genetic amniocentesis for fetal karyotyping in singleton pregnancies with increased fetal NT thickness. RESULTS: Of the 3151 singleton pregnancies included in our study, 171 cases (5.4%) of increased (> or =3.0 mm) NT were noted. Fetal chromosomal abnormalities were identified in 22 (12.9%) of these pregnancies, including 9 with trisomy 21, 5 with trisomy 18, 4 with 45,X and 4 with unbalanced structural abnormalities. Major defects of the heart and the great arteries were identified in 13 (7.6%) of these pregnancies with increased NT. These included eight pregnancies that also had the diagnosis of chromosomal aneuploidy. Among the 22 fetuses with confirmed aneuploidy, all 5 fetuses with trisomy 18, 1 of the 4 fetuses with 45,X and 2 of the 9 fetuses with trisomy 21 had increased fetal NT thickness associated with abnormal fetal echocardiography findings. CONCLUSIONS: Screening for Down syndrome and cardiac defects using first-trimester fetal NT measurement in combination with fetal echocardiography at 16 to 18 weeks of gestation is a feasible and sensitive procedure for the prenatal detection of trisomy 18.