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

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.

Outcome of antenatal invasive diagnostic tests in a fetal medicine unit with low case load in North Wales, United Kingdom

The aim of this retrospective cohort study was to review rate of miscarriage following antenatal invasive diagnostic procedures from a unit where relatively low annual numbers of procedures are undertaken. Data were analysed for 201 chorionic villous samplings (CVSs) performed between January 2007 and June 2019 and 511 amniocenteses performed between January 2008 and June 2019, in singleton pregnancies. The miscarriage rates after CVS was 0% at 48 hours, 0.6% at 2 weeks and 2.5% up to 24 weeks of gestation. All four miscarriages following CVS had significant inherent high-risk features, therefore, it would be inappropriate to attribute these losses solely to the procedure itself. None of the women who had an amniocentesis had a miscarriage during the study period. We did not find a causal association between number of invasive procedures performed by an operator and miscarriage rate in our setting even with low annual numbers of invasive procedures.Impact StatementWhat is already known on this subject? Royal College of Obstetricians and Gynaecologists (RCOG) of UK recommends a minimum of at least 30 CVSs or amniocenteses procedures per year for a practitioner in order to maintain skills. A centre performing more fetal invasive procedures has lower miscarriage rates due to more experience of practitioners.What the results of this study add? This study is the first long-term audit data from a smaller fetal medicine unit with relatively low annual case load, suggesting that miscarriage risk may actually be lower than the current understanding. No additional risk of miscarriage or pregnancy loss following fetal invasive procedures even with relatively low annual numbers than that recommended by the RCOG.What the implications are of these findings for clinical practice and/or further research? The findings of this study are important in the era of non-invasive prenatal testing which will see the overall number of fetal invasive procedures decline with time. Competence in safely undertaking antenatal invasive procedure can possibly be maintained with lower annual procedure numbers. Units undertaking low number of antenatal invasive procedure must continuously audit their practice to ensure satisfactory standards and outcomes. More research is needed from smaller units to corroborate or refute the findings of this study.

[Prognosis of fetuses with cystichygroma and nuchal translucency/nuchal fold thickening on prenatal echography]

OBJECTIVE

To analyze the prognosis of fetuses with cystic hygroma (CH) or nuchal translucency (NT) or nuchal fold (NF) thickening detected by prenatal echography.

METHODS

From January 2014 to December 2015, 124 fetuses with CH and NT/NF thickening on prenatal echography were enrolled from Women's Hospital of Zhejiang University School of Medicine. The basic clinical information, ultrasonic results, pregnancy outcomes and newborn follow-ups were analyzed. The cases were grouped by prognosis and the factors affecting prognosis were analyzed with logistic regression.

RESULTS

There were 85 cases of labor induction including one stillbirth and 39 cases delivered. Except one infant who died after birth, all live births survived with good prognosis. Univariate analysis showed that the gestational age at diagnosis of poor prognosis group was earlier than that of good prognosis group (P<0.01); and the former group also had higher hydrops fetalis rate and additional structural anomalies rate (all P<0.01). Multivariate regression analysis showed that hydrops fetalis (OR=90.105, P<0.05) and additional structural anomalies (OR=61.854, P<0.05) were risk factors of poor prognosis in fetuses with CH and NT/NF thickening.

CONCLUSIONS

Fetuses with diagnosed CH or NT/NF thickening on prenatal ultrasonography are likely to be associated with chromosomal abnormality. Early gestational weeks, hydrops fetalis and additional structural anomalies may indicate poor prognosis.

Genetic Burden and Outcome of Cystic Hygromas Detected Antenatally: Results of 93 Pregnancies from a Single Center in the Northern Region of Turkey

Objective:

Genetic burden, fetal malformations, and fetal outcomes of 93 fetuses with cystic hygroma (CH) are reported from a single center in Turkey.

Patients and Methods:

Pregnancies, having a diagnosis of fetal CH, detected between January 2010 and October 2016, were included in the study except fetuses having increased nuchal translucency. Fetal age/gender, maternal age, the age of pregnancy, types of fetal malformations, karyotype, and outcomes were evaluated.

Results:

The average gestational age was 16.2 weeks. Nearly 47% of the pregnancies had multiple congenital anomalies, of which 58% had a chromosomal anomaly. Chromosomal anomaly rate was 68.2% in patients with hydrops fetalis. Aneuploidies were major chromosomal defects. All trisomies were of regular type except one with Robertsonian translocation (46, XY, +13, rob[13;14][q10;q10]). Seventy-four percentage pregnancies were terminated due to either fetal/karyotype anomaly.

Conclusion:

Characteristics of fetal CH were similar in different ethnical backgrounds. Aneuploidy is the dominant chromosomal constitution of fetal CH. Little information was known about the genes involved. Gene dosage effect implies that fetal CH is a complex genetic situation involving multiple genes interactions. For proper genetic counseling, each fetus with CH should be karyotyped, and fetal ultrasound examination should be performed. In the case of normal chromosome set, application of aCGH should be considered.

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.

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.

Prenatal Diagnosis of Cystic Hygroma related to a Deletion of 16q24.1 with Haploinsufficiency of FOXF1 and FOXC2 Genes

We report the prenatal diagnosis of cystic hygroma that was subsequently identified to have haploinsufficiency of the FOXF1 and FOXC2 genes via array comparative genomic hybridization (aCGH). Deletion o f these genes has previously neither been associated with cystic hygroma nor prenatally diagnosed. The FOX gene cluster is involved in cardiopulmonary development. This case expands the phenotypic spectrum o f abnormalities of the FOXF1 and FOXC2 genes, as it seems within the spectrum of function that disruption of the FOX gene cluster would lead to include abnormalities of prenatal onset. Identification of this association would not be possible with conventional karyotype or targeted aCGH. This case highlights the power of whole genomic aCGH to further delineate the etiology of birth defects.

Ultrasound diagnosis of severe mesomelic dysplasia in two fetuses, associated with increased neck translucency and tetralogy of Fallot in one and cystic hygroma in the other

Two stillborn male sibling fetuses born to the same parents had severe mesomelic dysplasia documented at ultrasound and confirmed by radiography and autopsy. The 17-week-old fetus with increased neck translucency had additional heart and great vessel anomalies consistent with tetralogy of Fallot. The 15-week-old fetus had a nuchal cystic hygroma. We posit that these sibs have a distinct, previously unreported skeletal dysplasia. The mode of genetic transmission could be autosomal recessive or X-linked recessive.

Nuchal cystic hygroma in five fetuses from 1819 to 1826 in the Meckel-anatomical collections at the University of Halle, Germany

The Anatomical collection of the Department of Anatomy and Cell Biology, Medical School of the University of Halle, Germany, comprises more than 8,000 specimens. Around 600 of them show congenital anomalies. The collection of abnormal human and animal fetuses began as the private collection of Johann Friedrich Meckel the Elder (1724-1774), his son Philipp Friedrich Theodor Meckel (1755-1803) and his grandson Johann Friedrich Meckel the Younger (1781-1833). Meckel the Younger founded the systematic science of developmental pathology. Radiographical techniques, computer tomographic (CT) methods, magnetic resonance imaging (MRI), and comparative genomic hybridization (CGH) were used to diagnose abnormal human fetuses in the Meckel-anatomical collections. Cystic hygroma colli was found in five of the human fetuses originally described by JF Meckel the Younger in 1826 and one of his students in 1819 [Hencke, 1819]. CGH analyses were used to test whether the observed cystic hygroma colli could be caused by chromosomal aneuploidies. CGH-ratio profiles of all chromosomes were apparently normal. PCR-based sex determination tests on ancient DNA were used to determine the fetal gonosomal constitution. It is likely that the Meckel specimens are among the oldest fetuses in which Ullrich-Turner "phenotype" has been diagnosed.

Spontaneous resolution of cystic hygroma in 47,XYY fetus

INTRODUCTION

47,XYY karyotype occurs in 1 out of 1,000 male births. Physical phenotype is normal, with tall stature by adolescence. Prenatal diagnosis of the 47,XYY syndrome is usually fortuitous. Some cases are being diagnosed when prenatal karyotyping is done for the detection of Down syndrome and other major aneuploidies. Some cases are diagnosed when prenatal ultrasonographic findings of fetal abnormalities are found. Herein, we report a case of 47,XYY after prenatal finding of fetal cystic hygroma with spontaneous resolution.

CASE REPORT

A 19-year-old primigravid woman presented for antenatal care at the 13th week of pregnancy. She used oral isotretinoin, being unaware of pregnancy, for a treatment of acne during the first 4 weeks of gestation. Ultrasonogram was performed due to first trimester screening and the history of isotretinoin exposure. The result revealed a single viable fetus compatible with a 13-week pregnancy and a posterior cervical cystic hygroma. No other structural anomalies were noted. An amniocentesis was performed for prenatal chromosome analysis and a 47,XYY karyotype was found. Repeated ultrasonogram at 23-week gestation showed that the cystic hygroma had spontaneously disappeared. She delivered a normal appearing male infant by spontaneous vaginal delivery at 40 weeks. The maternal and neonatal outcomes were uneventful.

CONCLUSION

Fetal cystic hygroma can be associated with abnormal karyotype, such as 47,XYY. Without hydrops fetalis, this may be ended with a normal outcome. Therefore, an antenatal karyotype determination should be offered to any woman whose fetus has cystic hygroma, even to those with spontaneous resolution.