Clinical course and outcome of fetuses with isolated cystic nuchal lesions and normal karyotypes detected in the first trimester

Cystic Hygroma: A Preliminary Genetic Study and a Short Review from the Literature

BACKGROUND

The objective of this study is to examine the hypothesis that cystic hygroma (CH) with normal karyotype can manifest as a Mendelian inherited trait, and that a genetic similitude with hereditary lymphedema exists. To reach this goal, we investigated the prevalence of genetic variants in angiogenesis and lymphangiogenesis genes in a cohort of euploid fetuses with CH that almost resolved before delivery. A short review of cases from literature is also reported.

METHODS AND RESULTS

Five fetuses were screened using a next-generation sequencing approach by targeting 33 genes known to be associated with vascular and lymphatic malformations. The genetic evaluation revealed two novel variants in KDR and KRIT1 genes.

CONCLUSION

A review of the literature to date revealed that an association exists between CH and hereditary lymphedema and, similar to lymphedema, CH can be inherited in autosomal recessive and autosomal dominant manner, with the latter most likely associated with a better prognosis. About KDR and KRIT1 genes, no other similar associations are reported in the literature and caution is needed in their interpretation. In conclusion, we thought that a genetic test for the outcome of familial CH could be of enormous prognostic value.

Complications in head and neck surgery

Head and neck anatomy is topographically complex and the region is densely populated by vital nerves and vascular and lymphatic structures. Injury to many of these structures is associated with significant morbidity and may even be fatal. A thorough knowledge of regional anatomy is imperative and complications need to be managed in a thoughtful directed manner. The pediatric surgeon may be called upon to address both congenital and acquired conditions and should be prepared to encounter reoperative fields after failed initial surgery. This review summarizes the current literature on four frequently encountered surgical conditions of the head and neck: branchial cleft anomalies, thyroglossal duct cyst, thyroid disease, and lymphatic malformations, with a focus on the prevention and treatment of complications.

Prenatal management, pregnancy and pediatric outcomes in fetuses with septated cystic hygroma

It has been reported that, compared with simple increased nuchal translucency, fetal cases with septated cystic hygroma (CH) are more likely to face perinatal handicaps. However, pediatric outcomes and proper prenatal counseling for this anomaly have not yet been truly defined. We performed this study to determine pregnancy and pediatric outcomes of fetuses with septated CH. We searched records for cases with septated CH and collected data for structural abnormalities, karyotype analysis, and pregnancy outcomes. Fetuses born with septated CH were also evaluated for their pediatric outcomes. Sixty-nine fetuses with septated CH were enrolled in the study. Results showed that chromosomal abnormalities were present in 28 fetuses (40.6%), and the most common aneuploidy was Turner syndrome (n=14, 20.3%); 16 (23.2%) of the remaining cases, in which aneuploidy was not found, had coexistent structural malformations; 25 (36.2%) cases had normal karyotype and morphology. The total number of live births and infants with unfavorable neurologic follow-up were 13 (18.8%) and 2 (2.9%), respectively. Septated CH is associated with poor perinatal outcomes; therefore, karyotype analysis and ultrasonographic anomaly screening should be performed as initial steps, and expectant management should be offered to couples with euploid fetuses that have normal morphology.

Additional first-trimester ultrasound markers

The first trimester (11-13 +6 weeks) ultrasound examination is useful for several reasons: determination of an accurate date of confinement, diagnostic purposes, and screening for fetal defects. Nuchal translucency measurement combined with maternal serum markers (free b-human chorionic gonadotropin and pregnancy-associated plasma protein A) is the mainstay of first-trimester screening for chromosomal defects. However, over the past decade additional ultrasound markers have been developed that improve the performance of this type of screening. The novel markers include evaluation of the nasal bone, fronto-maxillary angle measurement, and Doppler evaluations of the blood flow across the tricuspid valve and in the ductus venosus.

First Trimester Ultrasound Screening: An Update

For many years, the main use of ultrasound in the first trimester of pregnancy was to confirm viability and to establish gestational age. Indeed, the crown-rump length measurement in the first trimester remains the most accurate method to estimate the gestational age even today. However, improvements in ultrasound equipment and improvement in our understanding of normal and abnormal fetal development allows us now to perform a much more complete first trimester fetal evaluation. This pertains not only to the diagnosis of fetal anomalies but also to screening for fetal defects. The combination of the nuchal translucency measurement and maternal serum biochemistries (free β-hCG and PAPP-A) has been shown to be an extremely efficient way to screen for fetal aneuploidy. The addition of other first trimester markers such as the nasal bone evaluation, frontomaxillary facial angle measurement, and Doppler evaluation of blood flow across the tricuspid valve and through the ductus venosus improves the screening performance even further by increasing the detection rates and decreasing the false positive rates. Several of the first trimester markers also are useful in screening for cardiac defects. Furthermore, significant nuchal translucency thickening has been associated with a variety of genetic and nongenetic syndromes. A recently described first trimester marker called the intracerebral translucency appears to hold great promise in screening for open spine defects. Finally, it appears that a first trimester evaluation (uterine artery Doppler and the measurement of certain biochemical markers in the maternal serum) significantly improves the assessment of the risk of preeclampsia.

First trimester ultrasonography in screening and detection of fetal anomalies

An obstetrical ultrasound examination provides invaluable information regarding the fetus. Until the mid-1980s, ultrasound in the first trimester was limited to localization of the pregnancy, establishing viability, and accurate dating. With the advent of high-resolution ultrasound and transvaginal scanning, a significant amount of information about the fetus can be gained and provided to the patient at a very early stage in gestation. This article provides an overview of the role of first trimester (11-13 + 6 weeks' gestation) ultrasound in screening and diagnosis of fetal anomalies. The first trimester is an ideal time for screening for aneuploidy, primarily due to the advantages that nuchal translucency (NT) measurement provides. NT measurement is also useful in establishing the risk of congenital cardiac disorders and a number of genetic and non-genetic syndromes. Significant NT thickening is associated with an increase in perinatal morbidity and mortality. Potential mechanisms resulting in increased NT are discussed. A number of new ultrasound markers for fetal aneuploidy have been investigated over the past several years, some of which appear to improve the screening efficacy of early ultrasonography. The role of these is reviewed. A number of fetal anomalies can now be consistently diagnosed in the first trimester. Their appearance at this early gestational age is discussed as well. It is clear that, data obtained by first trimester ultrasound are useful in counseling expectant parents and in planning the appropriate follow-up.

[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.

Pediatric Admissions and Procedures for Lymphatic Malformations in the United States: 1997 and 2000

OBJECTIVE

To describe the incidence of discharges for lymphatic malformation (LM) and the various treatments rendered for this condition in a nationwide sampling of pediatric discharges from 1997 and 2000.

DATA SOURCE

The 1997 and 2000 Kid's Inpatient Database (KID), available through the Agency for Healthcare Research and Quality (AHRQ).

DATA EXTRACTION

The sampling scheme of this database allowed for calculation of national and regional estimates using STATA 8.2.

DATA SYNTHESIS

There were an estimated 3200 admissions for the treatment of pediatric LM in 1997 and 2000 combined. These admissions were most common in urban teaching institutions (69% in 1997 and 81% in 2000). The mean age at admission was 3.7 years, while the median was 1 year. The most common procedure performed in these children was surgical excision of the malformation. Over half of these were done in children under age 2. Airway endoscopy was the second most common procedure. Sclerotherapy was infrequently performed. The estimated national hospital charges for these admissions were $26 million in 1997 and $35 million in 2000.

CONCLUSIONS

This analysis reveals a national perspective on the total number of pediatric admissions for LM and their associated inpatient procedures. Treatment trends for pediatric LM have remained relatively stable between 1997 and 2000, but hospital charges have increased.

Increased nuchal translucency with normal karyotype

Increased fetal nuchal translucency (NT) thickness between 11 and 14 weeks' gestation is a common phenotypic expression of chromosomal abnormalities, including trisomy 21. However, even in the absence of aneuploidy, nuchal thickening is clinically relevant because it is associated with an increase in adverse perinatal outcome caused by a variety of fetal malformations, dysplasias, deformations, dysruptions, and genetic syndromes. Once the presence of aneuploidy is ruled out, the risk of perinatal outcome dose not statistically increase until the nuchal translucency measurement reaches 3.5 mm or more (>99th percentile). This increase in risk occurs in an exponential fashion as the NT measurement increases. However, if the fetus survives until midgestation, and if a targeted ultrasound at 20 to 22 weeks fails to reveal any abnormalities, the risk of an adverse perinatal outcome and postnatal developmental delay is not statistically increased.

Population-based study of the outcome following the prenatal diagnosis of cystic hygroma

OBJECTIVE

To identify the population prevalence, pregnancy outcome, and the pattern of associated anomalies with a prenatal diagnosis of cystic hygroma.

DESIGN

We analysed the pregnancy outcomes from 99 cases of prenatally diagnosed cystic hygroma reported to the Trent Congenital Anomalies Register from 1 January 1997 to 31 December 1999, by means of an outcome reporting form completed by the notifying centre.

RESULTS

We identified a population prevalence of 1 in 1775 livebirths for prenatally diagnosed cystic hygroma. There were 64 terminations of pregnancy, 19 spontaneous pregnancy failures, and 16 livebirths. Of the 87 pregnancies karyotyped, 53 (61%) demonstrated aneuploidy with Turner syndrome being the most common, 29 (33%). There were a large variety of structural malformations identified, however, only 14 out of 83 terminations of pregnancy and spontaneous pregnancy failures had post-mortem examinations. Termination of pregnancy for Turner syndrome not complicated by identified structural malformations was the norm. Of the 16 livebirths, only 6 were normal at birth, 1 other has had successful hygroma surgery. Four of the liveborn infants have since died.

CONCLUSIONS

The 'normal outcome' rate from pregnancies complicated by prenatally diagnosed cystic hygroma is less than 10% in this study (6/99). Prenatal diagnosis of cystic hygroma requires careful assessment of the fetus, with regard to both karyotyping and ultrasound. Post-mortem examination should be encouraged after termination of pregnancy, or spontaneous pregnancy loss. This is important not just to the current pregnancy but also for future pregnancies.

Outcome of pregnancy in chromosomally normal fetuses with increased nuchal translucency in the first trimester

OBJECTIVES

To study the outcome of chromosomally normal pregnancies with increased nuchal translucency at the 10-14-week scan.

DESIGN

Retrospective study of 1320 chromosomally normal singleton pregnancies with nuchal translucency of > or = 3.5 mm. In addition to fetal karyotyping these patients were managed with follow-up scans at 14-16 and 20-22 weeks, specialist fetal echocardiography and in selected cases by infection screening and further genetic testing.

RESULTS

In the 1320 pregnancies there were 68 (5.15%) spontaneous abortions or intrauterine deaths, 18 (1.36%) neonatal and infant deaths and 154 (11.67%) terminations of pregnancy. In the 1080 (81.82%) survivors, 60 (5.56%) had abnormalities requiring medical or surgical treatment or leading to mental handicap. The chance of a livebirth with no defects in the group with nuchal translucency of 3.5-4.4 mm was 86%, for those with translucency of 4.5-5.4 mm it was 77%, for those with translucency of 5.5-6.4 mm it was 67%, and for those with translucency of > or = 6.5 mm it was 31%.

CONCLUSIONS

Increased fetal nuchal translucency is associated with chromosomal abnormalities, many fetal defects and genetic syndromes. In the majority of cases a series of antenatal investigations, including fetal karyotyping, detailed scans, fetal echocardiography, as well as genetic testing and infection screening, that can be completed by 20 weeks of gestation would distinguish between the pregnancies destined to result in adverse outcome and those leading to the delivery of infants without major defects.

First-trimester ultrasound

There has been an increase in the use of fetal ultrasound in the first trimester. This article reviews the published literature with emphasis on fetal nuchal translucency (NT). When measured according to well-defined guidelines, increased NT identifies about 80% of chromosomal anomalies for a false-positive rate of about 5%. Increased NT may indicate the presence of structural defects or genetic disorders, and it is relatively frequently seen in monochorionic pregnancies prone to develop twin-twin transfusion syndrome.

Nuchal translucency and its relationship to congenital heart disease

Nuchal translucency refers to the normal subcutaneous space, observed on first trimester ultrasound evaluation, between the skin and cervical spine. Increased nuchal translucency is known to be associated with an increased risk of aneuploidy, particularly Trisomy 21, and recent studies have also identified increased nuchal translucency as a nonspecific marker for various genetic syndromes and multiple structural anomalies, to include congenital heart disease. This increased risk applies to euploid and aneuploid pregnancies and is directly related to the degree of nuchal translucency thickening. This article reviews the role of nuchal translucency as a screening tool for congenital heart disease.

First trimester screening for structural fetal abnormalities: nuchal translucency sonography

Nuchal translucency refers to the normal subcutaneous space, observed on first trimester ultrasound examination, between the skin and the cervical spine in the fetus. Increased nuchal translucency is known to be associated with an increased risk of aneuploidy, particularly Down syndrome. In addition to this association with aneuploidy, multiple studies have now identified increased nuchal translucency as a nonspecific marker of a wide range of fetal structural abnormalities, to include congenital diaphragmatic hernia, cardiac defects, and various genetic syndromes. The degree of nuchal translucency is directly related to the prevalence of fetal anomalies and may have prognostic significance, especially when found in association with other anomalies. The pathophysiology of increased nuchal translucency is uncertain but may be the result of cardiac failure or alterations in lymphatic drainage. Increased nuchal translucency may identify pregnancies that require further assessment, to include additional sonographic evaluation and possible fetal echocardiography. Further evaluation is required to assess the role of nuchal translucency screening in the general population.

Prenatal features of Noonan syndrome

We report six cases of Noonan syndrome which presented prenatally with sonographic abnormalities. These included increased nuchal fluid, short femora, pleural effusions, hydrops, cardiac and renal abnormalities. A review of all cases of Noonan syndrome seen at two regional genetics centres confirms the association with these sonographic abnormalities. These cases demonstrate the diversity of prenatal presentation of Noonan syndrome and highlight the need to consider this diagnosis, particularly when faced with a fetus with a normal karyotype and varying degrees of oedema or hydrops, with a short femur length.

Diagnosis and management of fetal nuchal translucency

Fetal nuchal translucency can be measured in most pregnant women in the first and early second trimester. The size of translucency varies slightly with gestational age and crown rump length and is independent of maternal age. Most authors have used a nuchal thickness of > or = 2.5 mm or > or = 3 mm to define abnormal, although some have suggested that the normal variation with gestation requires that different thresholds be used at different gestational ages. The accuracy of nuchal translucency measurement varies between examiners and between patients, likely in relation to examiner skill and image resolution. The small size of a nuchal translucency, less than 3 mm in most cases, probably approximates the threshold of normal interexaminer and intraexaminer variability. The presence of a thickened nuchal translucency is associated with chromosomal abnormality and perhaps with structural abnormality even when the karyotype is normal. Because of the reported variations in the populations studied, the methods used, and the results of screening, it is inappropriate at this time to assign a numeric risk to any individual patient with this finding. However, in both high-risk and low-risk groups, the positive predictive value appears to be high enough that patients with increased nuchal translucency should be counseled by their obstetrician and prenatal diagnostic testing should be offered. Because early genetic diagnosis by CVS has a substantially higher procedure-associated loss rate than amniocentesis in the second trimester, many patients may elect to wait for chromosomal testing. If so, disappearance of nuchal thickening should not be taken as reassurance. As a screening test to be widely applied to a general or low-risk population, the utility of fetal nuchal translucency measurement is uncertain. The reported sensitivity for identification of trisomy 21 has ranged from about 40% to 80%, and the sensitivity for identification of other aneuploidies may be lower than for Down's syndrome. From a cost-risk-benefit standpoint, universal first-trimester ultrasound screening has not been appropriately compared with standard risk assessment using maternal age and multiple-marker serum screening, with amniocentesis as the predominant diagnostic method. Also, the issues of availability and reimbursement have not been addressed. Currently, measurement of nuchal translucency is not a substitute for the standard of obstetrical care, which is to offer multiple-marker serum screening to every pregnant woman at 15 to 20 weeks. Similarly, it is inappropriate to substitute nuchal translucency measurement for genetic counseling and CVS or amniocentesis in women above 35 years of age or those with a significant positive history. Finally, the data are not clear as to whether a normal nuchal translucency decreases the likelihood of chromosomal abnormality in a high-risk population, and such women should not be discouraged from invasive testing because of a normal first-trimester ultrasound study. The data supporting the association between thickened nuchal transluency and chromosomal abnormality are compelling, but further study is needed before adopting routine nuchal translucency screening. Combining first-trimester ultrasonography with early serum screening is currently being investigated and may ultimately prove to be the most efficient means of screening for chromosomal anomaly.

Outcome of chromosomally normal livebirths with increased fetal nuchal translucency at 10-14 weeks' gestation

The aim of this study was to determine the outcome of chromosomally normal livebirths with increased fetal nuchal translucency at 10-14 weeks' gestation. Clinical follow up of 89 chromosomally normal livebirths that in fetal life had a minimum nuchal translucency thickness of 3.5 mm and a comparison group of 302 infants whose fetal nuchal translucency thickness at 10-14 weeks of gestation was less than 3.5 mm was performed. Major abnormalities, mainly structural defects of the cardiovascular or skeletal systems, were found in 10.1% (nine of 89) of the group with increased translucency, compared to 2% (five of 302) in those with translucency of less than 3.5 mm (chi2=11.9, p<0.001). Delay in achievement of developmental milestones was observed in one of the infants with increased translucency and in one of the comparison group. The findings of this study show that in chromosomally normal fetuses increased nuchal translucency thickness at 10-14 weeks of gestation is a marker for fetal abnormalities including structural defects and genetic syndromes.

Diagnosis and management of early non-immune hydrops fetalis

Fetal hydrops is a common symptom of fetal disease at any stage of gestation. The aetiological mechanisms leading to non-immune fetal hydrops are complex and their impact variable at different stages of gestation. In early pregnancy, primary or secondary intra-uterine cardiac failures due to major cardiovascular defects are more often linked to a chromosomal abnormality than during the second half of gestation. In these cases, an increase of the nuchal translucency thickness is probably the first stage of fetal hydrops. Depending on the severity of the underlying defect, the next stage is generalized skin oedema with eventual placental oedema, ascites and pleural effusion. The natural history of fetal hydrops remains poorly understood and thus the prognostic factors determining fetal outcome are still unknown. Examination of the fetal nuchal anatomy between 10 and 15 weeks of gestation and the follow-up of these pregnancies offer an opportunity for an early screening in most aneuploidies and cardiovascular defects, and a better understanding of the aetiopathology of fetal hydrops.

Ultrasound imaging of fetal neck anomalies: implications for the risk of aneuploidy and structural anomalies

This study summarizes 24,000 transvaginal ultrasound examinations which were performed in a predominantly low-risk population at 14-16 weeks' gestation. 1254 (5.2 per cent) fetuses had a nuchal fold or a non-septated cystic hygroma. Of these fetuses, 140 (11.1 per cent) had additional structural anomalies. Cardiovascular anomalies were the most commonly detected structural malformations. Forty-three (3.4 per cent) fetuses were aneuploid. Trisomy 21 was the most common chromosomal anomaly (n = 27). Aneuploidy was significantly more common in fetuses who had a nuchal finding and an associated structural anomaly. The prevalence of nuchal fold and non-septated cystic hygroma, as well as the incidence of their associated structural anomalies, was similar. Based on these data, it is concluded that a complete ultrasonic survey of the fetus and karyotyping are advocated in fetuses with a nuchal abnormality, irrespective of maternal age or triple serum screening results.

Pathological significance of first-trimester fetal nuchal oedema

The pathological mechanism that causes the transient phenomenon sonographically defined as "nuchal translucency' is still poorly understood. Seven pregnancies in which the fetuses clearly presented this ultrasonic sign at 10-14 weeks' gestation were terminated because of an abnormal fetal karyotype. The pathological specimens, compared by morphometric analysis with normal fetuses of the same gestational age, showed oedema and dilatation of lymphatic capillary vessels. No particular relationship was found with any structural abnormality. We speculate that nuchal oedema is a transient non-specific phenomenon which is probably related to an early disarrangement of lymphatic connections.

Fetal outcome in nuchal translucency with emphasis on normal fetal karyotype

The aim of this study was to evaluate fetal outcome in fetuses with a nuchal translucency thickness of 3 mm or more, with emphasis on those with a normal karyotype. Between 1991 and 1994, a total of 104 pregnancies with suspected ultrasound abnormalities were referred to our prenatal unit for a fetal anomaly scan before 16 weeks of gestation. Of these 104 pregnancies, 54 were referred because of a nuchal translucency thickness of 3 mm or more. Data on these 54 pregnancies will be presented. Karyotyping was performed in all cases. An abnormal karyotype was found in 26/54 (48 per cent) pregnancies. A normal karyotype was established in the remaining 28 pregnancies. In this subset, five associated structural anomalies were detected at the first anomaly scan (9-15 weeks). Two pregnancies were terminated because of isolated nuchal translucency. In four of the continuing 21 pregnancies, additional structural anomalies were detected only at the second anomaly scan (16-20 weeks). Two of these were terminated because of bilateral renal dysplasia and a combination of exomphalos and ectopia cordis. Finally, 19 pregnancies progressed uneventfully and resulted in spontaneous delivery at a median gestational age of 40 weeks. A statistically significant difference in mean nuchal translucency thickness was found between cases with and without associated structural anomalies. This relationship indicates a more pronounced nuchal translucency thickness to be associated with a higher incidence of additional structural anomalies and, as a result, a poorer fetal outcome.