Second-trimester cystic hygroma: prognosis of septated and nonseptated lesions

A Pain in the Neck: Lessons Learnt from Genetic Testing in Fetuses Detected with Nuchal Fluid Collections, Increased Nuchal Translucency versus Cystic Hygroma-Systematic Review of the Literature, Meta-Analysis and Case Series

Fetal Nuchal fluid collections can manifest with two distinct presentations attributable to the same phenotypic spectrum: increased nuchal translucency (iNT) and cystic hygroma. The prenatal detection of these findings should prompt an accurate assessment through genetic counseling and testing, including karyotype, chromosomal microarray analysis (CMA) and multigene RASopathy panel. We performed a systematic review of the literature and meta-analysis, to calculate diagnostic yields of genetic testing in fetuses with iNT and cystic hygroma. We compared the results with a cohort of 96 fetuses with these isolated findings. Fetuses with isolated NT ≥ 2.5 mm showed karyotype anomalies in 22.76% of cases and CMA presented an incremental detection rate of 2.35%. Fetuses with isolated NT ≥ 3 mm presented aneuploidies in 14.36% of cases and CMA had an incremental detection rate of 3.89%. When the isolated NT measured at least 3.5 mm the diagnostic yield of karyotyping was 34.35%, the incremental CMA detection rate was 4.1%, the incremental diagnostic rate of the RASopathy panel was 1.44% and it was 2.44% for exome sequencing. Interestingly, CMA presents a considerable diagnostic yield in the group of fetuses with NT ≥ 3.5 mm. Similarly, exome sequencing appears to show promising results and could be considered after a negative CMA result.

Current Perspectives of Prenatal Cell-free DNA Screening in Clinical Management of First-Trimester Septated Cystic Hygroma

First-trimester septated cystic hygroma occurs in approximately 1 in 268 pregnancies and has long been associated with a markedly increased risk of fetal aneuploidy and, among euploid fetuses, an increased risk of structural anomalies primarily affecting the cardiac and skeletal systems. Invasive prenatal diagnosis – chorionic villus sampling and/or amniocentesis – encompasses the time-honored clinical tools for the next step in management following prenatal sonographic diagnosis of first-trimester septated cystic hygroma. Currently, prenatal cell-free DNA (cfDNA) screening for fetal aneuploidy with select microdeletions is gradually replacing the considerably less sensitive, and labor-intensive combined first-trimester screening. These new technologies have opened potential new venues in the clinical management of this ominous late first-trimester sonographic diagnosis. Advances in cfDNA technologies are now permitting detection of chromosomal copy number variants (CNV) larger than 7Mb across genome and select serious single-gene disorders (mainly impacting skeletal and neurological development), affecting quality of life and may benefit from medical and/or surgical management. This commentary will address the available non-invasive prenatal screening technologies, which clearly enhance immediate genetic analysis modalities applicable in the presence of the complex sonographic finding of first-trimester septated cystic hygroma.

A unique case of recurrent fetal cystic hygroma: first fetus with an inherited heteromorphism of chromosome 1 (1qh+) and the second fetus with 69XXX triploidy

The authors report a unique recurrent septated cystic hygroma (CH), on two successive pregnancies, at five years interval. The chromosome analysis of the first fetus showed an increase in length of heterochromatin on the long arm of chromosome 1 – 1qh+, a chromosomal polymorphism inherited from mother, 46XX,1qh+,14ps+,21ps+. The karyotype of the second CH, with more severe ultrasound (US) imaging, showed a 69XXX triploidy. The patient took no risk and underwent each time a termination of pregnancy (TOP). The first karyotype is generally considered “normal”, although there are few reports linking 1qh+ with low fertility, but this was not the case, the patient having, from a previous marriage, a healthy boy and two TOPs. So, this “particular”, but “healthy” karyotype was not a cause for the first CH. The second karyotype highlights a possible causality between the 69XXX triploidy, usually associated with partial hydatidiform mole, and a more severe septated CH in the last fetus. Neither the CHs’ appearance nor their recurrence seemed to be family linked, as the two CHs had distinct genetic profiles. We recommend that, once CH is diagnosed, a careful US examination is compulsory for the determination of subcutaneous edema, ascites, pleural and pericardial effusions and cardiac or renal abnormalities; an early genetic work-up is mandatory, by chorionic villus sampling or amniocentesis. However, a “healthy” karyotype does not exclude a severe form, as in our first case of CH. Due to the very poor outcome of fetuses with CH, the patient must be thoroughly informed about the short and the long-term fetal prognosis.

Outcome of 45,X fetuses with cystic hygroma: A systematic review

This objective of this systematic review was to estimate live birth rate and explore prognostic indicators in fetuses with 45,X karyotype and a posterior cystic hygroma (CH). Electronic databases were searched and studies reporting pregnancy outcomes (termination, spontaneous abortion, demise, or live birth) for fetuses with 45,X karyotype and a CH diagnosed on ultrasound were included. For cases of survival, CH characteristics, presence of hydrops fetalis, or concomitant anomalies, delivery details, and postnatal outcomes were summarized. A total of 95 studies, including 535 cases, met inclusion criteria: 285 (53.3%) pregnancies were terminated, 72 (13.5%) had spontaneous abortion or demise, 164 (30.7%) had unspecified pregnancy failure, and 14 (2.6%) were live births. Among live births with data available, all CH measured 2-7 cm, more than half were septate, and almost all regressed in size or eventually disappeared. Hydrops fetalis was noted in five cases. Of the eight live births with neonatal outcomes available, three neonates died shortly after birth and five survived past the neonatal period. This review suggests that diagnosis of CH in a 45,X fetus is associated with an estimated live birth rate of 2.6%, but only 1% survive to infancy. Prognosis appears to improve with CH regression.

Relationship between first trimester nuchal septations and chromosomal anomalies

OBJECTIVES

This study aimed to evaluate the association of nuchal septations with chromosomal anomalies during the first trimester of pregnancy.

METHODS

A total of 281 patients who were diagnosed to have elevated nuchal translucency (NT > 3 mm) or nuchal septations during the first trimester from Jan. 2014 to Dec. 2016 were included. These patients were divided into three groups: 1) patients with NT thickness between 3 and 5 mm and without nuchal septations (NT 3-5 mm group, n = 124), 2) patients with NT thickness > 5 mm and without nuchal septations (NT > 5 mm group, n = 96), and 3) patients with nuchal septations (NS group, n = 61).

RESULTS

The rate of chromosomal abnormalities was significantly higher for patients in NS group compared to those in the NT 3-5 mm group (P < .01) and NT > 5 mm group (P < .01). After controlling for maternal age, maternal BMI, ethnicity and crown-rump length, nuchal septations were reported to be significantly associated with a higher risk of chromosomal anomalies compared with NT 3-5 mm (OR = 4.97; 95% CI: 2.76-10.77; P < .01) and NT > 5 mm (OR = 3.82; 95% CI: 1.87-7.21; P < .01) (P < .01).

CONCLUSIONS

Measurement of nuchal septations during the first trimester of pregnancy proves to be a useful ultrasound prognostic indicator of chromosomal anomalies.

Management and outcomes of cystic hygromas: experience of a tertiary center

PURPOSE

Cystic hygroma (CH) is a fetal sonographic finding with an incidence of 1%. Chromosomal abnormalities and structural malformations are commonly related with CH. We aimed to describe our experience and determine the association between diagnosis of CH and adverse pregnancy outcome.

METHODS

We retrospectively reviewed data of prenatal CH diagnoses over a ten-year period. Cases were evaluated for maternal age, gestational week at CH diagnosis, invasive procedure, karyotype result, associated abnormality and perinatal outcome. We categorized cases into two groups to understand the impact of maternal age on perinatal outcomes, and the cut-off was 35 years old.

RESULTS

Totally 28 individuals were enrolled in the study. The median maternal age at birth was 27.5 years old, and 7 patients were over 35 years old. Karyotype results were available for all individuals, and 15 had an abnormal chromosome (53.5%). Five fetuses had structural abnormalities, and they were all observed within patients under 35 years old. Healthy fetuses (without any problem at antenatal screening and birth) were found to be only 14.3% in advanced maternal age (AMA) group and 33.3% in young mothers.

CONCLUSIONS

Women with AMA and CH had a higher risk of having a baby with a chromosomal abnormality, as compared with younger women.

Prenatal Ultrasound Evaluation and Outcome of Pregnancy with Fetal Cystic Hygromas and Lymphangiomas

Cystic hygroma is a type of lymphangioma, which is a vascular anomaly associated with lymphatic malformations and formed by fluid accumulation mainly located at the cervi-cofacial and axillary regions. Cystic hygroma is mostly located in the neck (75%), followed by axilla (20%), retroperitoneum and intra-abdominal organs (2%), limbs and bones (2%), and mediastinum (1%). It is often associated with chromosome aneuploidies, hydrops fetalis, and even intrauterine fetal demise. The prognostic factors of the fetal cystic hygroma or lymphan-gioma are chromosome abnormalities, hydrops fetalis, septations, or thickness of the cystic hygroma and are associated with other major malformations. Prenatal managements including ultrasound serial follow-up, magnetic resonance imaging, or even intrauterine injection of sclerosing agents are suggested. For fetus with the risk of airway obstruction at delivery, ex utero intrapartum treatment is also indicated. Detailed prenatal counseling is necessary for better neonatal outcome.

Giant fetal lymphangioma at chest wall and prognosis: case report and literature review

OBJECTIVE

To report a rare liveborn case with a giant, septated, chest wall lymphangioma that underwent prenatal expectation treatment.

CASE REPORT

A case of giant fetal chest wall cystic lymphangioma was diagnosed prenatally at 19 weeks gestation. Expectation treatment was performed, carefully after prenatal counseling, ruling out other structural abnormalities. At 38 weeks gestation, ultrasound showed a multilocular, subcutaneous cystic mass of 12.3 cm × 9.2 cm × 11.0 cm located on the left chest wall and left upper arm. The tumor was surgically removed 4 days after birth, and no recurrence was observed in the following 18 months.

CONCLUSION

Our experience suggests that a large, septated fetal lymphangioma may still merit prenatal expectation treatment if there is no evidence for chromosomal and structural abnormality.

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.

Fetal axillary cystic hygroma: a case report and review

Cystic hygroma (CH) is a lymphatic malformation occurring different parts of fetal body, typically in the region of the fetal neck and axillary, abdominal wall, mediastinal, inguinal and retroperitoneal areas. CH has been associated with fetal aneuploidy, hydrops fetalis, structural malformations and intrauterine fetal death.

A 24-year-old gravida 1, para 1 was admitted to our hospital at 28 weeks of gestation. Ultrasonographic examination determined 28 weeks of gestation, singleton, alive fetus who had a mass derived from the right axillary region which was extending to the anterior and posterior thoracic wall with fluid-filled cavities about 12 cm in size. There was no evidence of intrathorasic or intraabdominal extension of mass. Cordocentesis was performed and karyotype examination was normal 46 XY. The fetal demise was found after the first visit. The patient was delivered vaginally after labor induction with oxytocin infusion. The fetal autopsy confirmed the diagnosis of CH.

The fetal CH carries high risk of aneuploidy and fetal malformations. Patients that have been diagnosed with CH in antenatal follow-ups should be assessed in terms of other anomalies. Fetal karyotyping should be done and the patient should be monitored for fetal hydrops. The birth should be planned in a multidisciplinary hospital and as neonatal resuscitation could be needed, pediatricians should be consulted.

Spontaneous resolution of multiple lymphangiomas of the colon: A case report

Lymphangioma of the colon is a relatively rare non-epithelial tumor and usually presents as a submucosal polypoid lesion. Many cases incidentally discovered are usually asymptomatic. However, they may present as abdominal pain or bleeding, and their resection is normally required. Lymphangioma itself is generally recognized as a benign tumor and no cases of malignant transformation have yet been reported, although its natural history is currently unknown. To the best of our knowledge, this study is the first to describe a case of spontaneous resolution in multiple colonic lymphangiomas without any specific treatment.

Multidisciplinary approach in cystic hygroma: prenatal diagnosis, outcome, and postnatal follow up

BACKGROUND

The aim of the present study was to determine prenatal follow up and clinical outcome in fetuses born with cystic hygroma.

METHODS

A series of 64 cystic hygroma patients, who were diagnosed in the first and the second trimester of pregnancy, was enrolled. Associated structural abnormalities, karyotype analysis and pregnancy outcome were studied. Survivors were followed for their fetal outcome and prognosis.

RESULTS

There were 64 new cases of cystic hygroma in 8524 subjects screened (0.75%). Thirty-nine (60.9%) were of non-septated and 25 (39.1%) were of septated cystic hygroma. Chromosomal abnormalities were present in 25 (39.1%). The most common abnormality in non-septated cystic hygroma was trisomy 21 (10, 27.8%), and that in septated cystic hygroma was Turner syndrome (5, 23.8%). Associated structural malformations are common in cystic hygroma and overall survival was poor. Nine of the present infants were live-born and were subsequently followed up. Two had cardiac pathology and died after cardiac operation, two others were diagnosed with axillary cystic hygroma, had an excellent prognosis and responded well to treatment, and another two had cranial findings with mild neurological sequel. Only three cases had, at birth and in the follow-up period, no complications.

CONCLUSION

Cystic hygroma is highly correlated with adverse perinatal outcome. Prenatal diagnosis and invasive procedures are vital for counselling with close follow-up after delivery for appropriate medical support. A multidisciplinary approach is strictly recommended in live-born children.

Isolated choroid plexus cyst or echogenic cardiac focus on prenatal ultrasound: is genetic amniocentesis indicated?

OBJECTIVE

The purpose of this study was to determine whether or not genetic amniocentesis is warranted when isolated choroid plexus cysts (CPC) or echogenic cardiac foci (EF) are noted on prenatal ultrasound.

STUDY DESIGN

We performed a retrospective analysis on patients from our perinatal database. All obstetric patients with CPC or EF noted on second-trimester perinatology ultrasound from April, 1998 to November, 2004 were included. Information regarding ultrasound findings and neonatal outcome were analyzed.

RESULTS

During the study period, 515 patients with CPC or EF were evaluated. Of these, 429 (83.3%) had isolated CPC or EF and 86 (16.7%) had additional risk factors. The incidence of abnormal karyotype was 0 versus 2.3%, respectively (P = .03). The additional risk factors considered were: advanced maternal age, abnormal serum triple marker screening, and/or other abnormal ultrasound findings. Furthermore, during the study period there were 20,122 live births and 27 (0.1%) cases of aneuploidy diagnosed postnatally. Of these, none had isolated CPC or EF on prenatal ultrasound.

CONCLUSION

CPC or EF noted on prenatal ultrasound warrants referral for careful consultative ultrasound evaluation. In the absence of other risk factors, however, genetic amniocentesis for isolated CPC or EF does not appear to be necessary.

Cystic hygroma and lymphangioma: associated findings, perinatal outcome and prognostic factors in live-born infants

OBJECTIVES

We aimed to determine associated ultrasonographic findings, chromosome abnormalities and the prognostic factors of cystic hygromas in live-born infants.

METHODS

We reported a series of 57 cystic hygroma cases, who were diagnosed in the first and the second trimester of pregnancy by means of the ultrasonographic morphology of cystic hygroma, associated structural abnormalities, karyotype analysis and the autopsy findings. Survivors were followed for their fetal outcome and prognosis.

RESULTS

There were 57 new cases of cystic hygroma among 8,155 screenings (0.7%). 35 of the cases (61.4%) were nonseptated and 22 of the cases (38.6%) were septated cystic hygroma. Chromosomal abnormalities were found in 23 of the cases (40.3%). The most common abnormality in nonseptated cystic hygroma was trisomy 21 (8 cases, 25%) and in septated cystic hygroma was Turner syndrome (4 cases, 21.1%). The most common associated structural malformations were cardiac abnormalities (in 7 cases, 20%) in nonseptated cystic hygroma cases and nonimmune hydrops (in 12 cases, 54.5%) in septated cystic hygroma cases. Overall survival was poor; only one case of septated cystic hygroma with axillary location and seven cases of nonseptated cystic hygroma, of whom two died in the neonatal period, were alive (10.5%). This study had 80% power to detect 0.03% difference in diagnosis cystic hygroma (alpha = 0.05, beta = 0.80).

CONCLUSION

Fetuses with cystic hygroma are at high risk for adverse outcome. Prenatal diagnosis with invasive procedures should be done in order to inform the parents in detail. Axillary location of the hygroma and the depth of invasion had prognostic importance.

Correlation of prenatal sonographic diagnosis and morphologic findings of fetal autopsy in fetuses with trisomy 21

OBJECTIVE

The purpose of this study was to compare the prenatal sonographic and postmortem pathologic findings of fetuses with trisomy 21.

METHODS

Among 22,150 fetal chromosome analyses, trisomy 21 was diagnosed in 207 fetuses between 1990 and 2004. Findings of second-trimester sonography and fetal autopsy were compared by organ system, and their correlation was assigned to 1 of 3 categories.

RESULTS

In total, 83.1% of the 184 fetuses that constituted the final study group had 1 or more abnormal structural findings at postabortion pathologic examination, whereas in 16.9% of the cases, fetal pathologic examination did not reveal any defects in fetal anatomy. Among major structural defects, the agreement between sonographic and autopsy findings was greater than 60% of all abnormalities of these systems: central nervous system (65.4%), heart (67.4%), fetal hydrops (100%), and cystic hygroma (93.3%), whereas the concordance rate was lower in these organ systems: abdominal abnormalities (46.2%), renal anomalies (50%), facial abnormalities (1.2%), and extremities (4.4%). The rate of additional major findings at autopsy was 34.2%. These mainly involved 3 organ systems: heart, head, and abdominal anomalies. Some sonographic findings (n = 16) were not verified at autopsy. The concordances between sonographic and autopsy findings regarding soft markers were considerably high in these markers: increased nuchal fold thickness (72%), short femur/humerus (75%), and pyelectasis (51.9%).

CONCLUSIONS

Examining the correlation between sonography and pathologic findings may indicate possible directions of further development in sonographic screening for trisomy 21. In addition to obstetricians, pediatricians, and geneticists, specialized perinatal pathologists have an important role in the multidisciplinary management of prenatally diagnosed fetal malformations.

Outcome of cystic hygroma in fetuses with normal karyotypes depends on associated findings

OBJECTIVE

To determine the associated diagnostic findings which are linked with adverse fetal outcome in nuchal cystic hygroma.

STUDY DESIGN

Based on a series of 32 cases, we determined the sonographic morphology of the hygroma, associated structural anomalies, karyotypes and autopsy findings. Intrauterine fetal death, spontaneous abortion and abnormal karyotypes were assigned as adverse outcome parameters.

RESULTS

The mean gestational age at diagnosis was 14.4 weeks (range 10-21). There were 18 nonseptated and 14 septated hygromas. Besides hygroma, associated sonographic detectable structural anomalies were observed in 17 cases (53.1%). The greatest number of associated sonographic anomalies were hydrops (31.3%), generalised skin oedema (6.3%) and pterygium colli (6.3%). Cytogenetic analysis revealed an abnormal karyotype in 13 of 26 (50%) invasive procedures. Turner syndrome and Trisomy 18 (both 15.4%) were the most frequent cytogenetic abnormalities. Autopsy was performed in 24 cases and 16 cases (66.7%) had an associated autopsy finding to hygroma colli. The most frequent associated autopsy findings were limb and craniofacial anomalies (both 25%). Only 3 (9.4%) mothers gave birth to healthy newborns. The overall fetal adverse outcome rate was 68.8% (22 cases).

CONCLUSIONS

Fetuses with NCH are at high risk for adverse outcome and detailed prenatal diagnosis including invasive procedures should be offered. According to the presented autopsy findings, to determine fetal outcome in NCH cases with normal karyotypes, detailed sonography should be concentrated beside the exclusion of fetal heart defects and existence of hydrops fetalis, on the skeletal, urogenital and craniofacial anomalies, as these might cause severe morbidity.

Descriptive Epidemiology of Cystic Hygroma: Hawaii, 1986 to 1999

OBJECTIVES

Cystic hygroma is associated with chromosomal abnormalities and a low chance of survival. The purpose of this study was to examine the relationship between cystic hygroma and various clinical and demographic factors.

METHODS

Cystic hygroma cases delivered in Hawaii from 1986 to 1999 were obtained from a population-based birth defects registry. The rate per 10,000 births was determined for various demographic and clinical factors.

RESULTS

The total cystic hygroma rate was 5.13 per 10,000 births. Chromosomal abnormalities were identified for 39% of the cases. There were no secular trends in cystic hygroma rates. Rates increased with increasing maternal age (P = 0.031). Rates were highest among Far East Asians, followed by Filipinos and whites, and lowest for Pacific Islanders. Cystic hygroma rates were higher in metropolitan Honolulu than in the rest of Hawaii. Rates were higher for females than for males. Cystic hygroma rates did not vary significantly by plurality.

CONCLUSIONS

Cystic hygroma rates were not found to be associated with delivery year or plurality, but were associated with maternal age, race and ethnicity, residence at delivery, and sex.

Screening for aneuploidy: the genetic sonogram

Over the past 10 years, the use of ultrasound in aneuploidy risk estimation has improved the way obstetrics is practiced. It allows patients to obtain more personalized risk assessment and has allowed many women a reasonable alternative to invasive testing. The addition of soft markers to the sonographic screening for aneuploidy has been extremely beneficial, especially when considered in combination with other ultrasound findings. The best estimate of risk seems to be achieved through the combined use of ultrasound, maternal serum screening, and maternal age. The literature supports the use of soft markers only when applied to the high-risk population, where the prevalence of aneuploidy is increased. If this information is applied to the low-risk populations, especially in isolation, the lower prevalence of aneuploidy makes the positive predictive value too low to be of any value in counseling patients. As with many screening tests it occasionally misses the diagnosis, and every patient needs to understand this potential shortcoming. It is a personal decision regarding their willingness to accept the risk of a missed diagnosis versus the risk of fetal loss from an invasive procedure. Although it is far from perfect, in the right hands and with appropriate counseling ultrasound is an excellent tool. This is such an important decision for women and their families, and it is worth the time it takes to explain the benefits and limitations of this test.

Cytogenetics and molecular cytogenetics in prenatal diagnosis

Prenatal chromosome diagnosis has been a rapidly changing field over the past 10 years for both sampling methodologies and molecular techniques to complement chromosome analysis. This review summarizes current techniques used by the clinician and their risks, and selected aspects of cytogenetic and molecular techniques used by the laboratories. Within the next 3 to 5 years, DNA techniques are expected to complement, and potentially replace, aspects of current cytogenetic and FISH techniques, and provide more detailed information on the genetic status of the fetus.

Prenatal diagnosis from cystic hygroma fluid: the value of fluorescence in situ hybridization

OBJECTIVE

We sought to determine the optimal approach to the prenatal chromosome analysis of cystic hygroma fluid using traditional cytogenetic analysis and fluorescence in situ hybridization.

STUDY DESIGN

A retrospective evaluation of our experience with traditional cytogenetic and fluorescence in situ hybridization analysis on cystic hygroma fluid was performed through a systematic review of the Genzyme Genetics database from January 1995 to July 2000. Information on gestational age, sample volume, clinical ultrasound findings (including fetal viability), cytogenetic results, fluorescence in situ hybridization results, and turn-around-time were queried.

RESULTS

Eighty-three specimens were included in the investigation. The mean gestational age was 18.1 weeks (range, 13-27 weeks), and the mean sample volume was 20.7 mL (range, 0.1-101 mL). Of the 72 samples in which > 5 mL of cystic hygroma fluid was available, the success rate for cytogenetic analysis was 76% (55/72 samples). In 11 specimens of < or = 5 mL of cystic hygroma fluid, cytogenetic analysis was successful in only 1 case (9%). Fluorescence in situ hybridization was attempted on 23 samples, 18 of which were successful (78%), including 6 of 9 cases of cell culture failure (67%). Both traditional cytogenetic analysis and fluorescence in situ hybridization were performed in 21 instances when a sample of > 5 mL was available. A successful result was obtained by either cytogenetic testing or fluorescence in situ hybridization analysis or both in 19 of 21 of these cases (90%). Samples of > 5 mL from viable fetuses had a higher cytogenetic success rate (80%) and fluorescence in situ hybridization success rate (89%) than samples from fetuses with intrauterine death (38% and 50% cytogenetic and fluorescence in situ hybridization success rates, respectively.) The mean turn-around time was 8.2 days (range, 4-17 days). Results were available in < or = 12 days in 91% of cases. There was a 91% aneuploidy rate identified, with 45,X occurring in 86% of the samples.

CONCLUSION

We conclude that the optimal approach for the prenatal diagnosis of chromosome abnormalities from cystic hygroma samples is to perform both traditional cytogenetic studies and interphase prenatal fluorescence in situ hybridization evaluation for the most common aneuploidies that involve chromosomes 13, 18, 21, X, and Y. With this combined approach, our data indicate that, in viable pregnancies with a fluid sample of >5 mL, a 90% diagnostic success rate can be achieved.

Cystic hygroma in the fetus and newborn

Cystic hygromas are developmental abnormalities of the lymphoid system that occur at sites of lymphatic-venous connection, most commonly in the posterior neck. They are frequently associated with karyotypic abnormalities, various malformation syndromes, and several teratogenic agents. The disease course of an infant with cystic hygroma is unpredictable. When diagnosed prenatally, the overall prognosis is poor. Cystic hygroma diagnosed after birth is usually associated with a good prognosis. This article reviews the embryologic, genetic, and pathologic correlates of these lymphatic system abnormalities, as well as the clinical course and outcome of the fetus and newborn with a cystic hygroma. Management strategies are reviewed, including newer nonsurgical therapies for the neonate with a cystic hygroma.

Screening for the aneuploid fetus

Advances in ultrasound technology have dramatically improved the detection of fetal defects. Although only an invasive test can provide a diagnosis, the incorporation of sonography into current biochemically based screening programs should significantly improve the detection of a host of other physically based fetal abnormalities. This article provides an overview and discussion of the prenatal sonographic features that may suggest the presence of a significant chromosomal abnormality.