Prenatal Isolated Ventricular Septal Defect May Not Be Associated with Trisomy 21

Apparently isolated ventricular septal defect, prenatal diagnosis, association with chromosomal aberrations, spontaneous closure rate in utero and during the first year of life: a systematic review

AIM

To evaluate the incidence of chromosomal aberrations in apparently isolated ventricular septal defects (VSD), quantify the timing of diagnosis of prenatally diagnosed VSDs, and define the spontaneous closure rate prenatally both in utero and during the first year of life.

Risk factor analysis for adverse prognosis of the fetal ventricular septal defect (VSD)

BACKGROUND

Ventricular septal defect (VSD) is the most common subtype of congenital heart disease. In the present study, we aimed to determine whether chromosome aberration was associated with the occurrence of VSD and evaluate the association of VSD size, location and chromosome aberration with adverse outcomes in the Chinese fetuses.

METHODS

Fetuses with VSD and comprehensive follow-up data were included and evaluated retrospectively. Medical records were used to collect epidemiological data and foetal outcomes. For VSD fetuses, conventional karyotype and microarray analysis were conducted. After adjusting confounding factors by using multivariable logistic regression analyses, the association between chromosome variations and VSD occurrence was explored. The association between defect size, location and chromosome aberrations and adverse foetal outcomes was also investigated.

RESULTS

Chromosome aberration was the risk factor for VSD occurrence, raising 6.5-fold chance of developing VSD. Chromosome aberration, peri-membranous site and large defect size of VSD were significant risk factors of adverse fetal outcome. Chromosome aberrations, including pathogenic copy number variations (CNVs) and variations of uncertain significance (VUS), were both risk factors, increasing the risk of the adverse fetal outcome by 55.9 times and 6.7 times, respectively. The peri-membranous site would increase 5.3-fold risk and defects larger than 5 mm would increase the 7.1-fold risk for poor fetal outcome.

CONCLUSIONS

The current investigation revealed that chromosomal abnormalities, large defects, and the peri-membranous site were all risk factors for poor fetal outcomes. Our study also indicated that chromosome aberration was one of risk factors for the VSD occurrence.

Should prenatal chromosomal microarray analysis be offered for isolated ventricular septal defect? A single-center retrospective study from China

Objective

To evaluate the utility of chromosomal microarray analysis (CMA) in fetuses with isolated ventricular septal defect (VSD) and to explore the favorable factors for predicting spontaneous closure of defects.

Methods

The study included 436 singleton pregnancies seen at a referral prenatal diagnosis center, between January 2016 and May 2020, of which 168 fetuses with isolated VSD were diagnosed in the prenatal setting. VSD was classified as an isolated VSD whether it had ultrasound soft markers or not. All patients underwent testing employing quantitative fluorescent polymerase chain reaction (QF-PCR) and CMA as the first-line genetic detection strategies, mainly in amniotic fluid and umbilical blood samples. Rates of chromosomal abnormalities were compared by subgroups of isolated VSD (muscular or perimembranous). Binary logistic regression analysis was performed to predict the independent determinants of spontaneous closure by 2 years.

Results

Overall, the CMA identified clinically significant copy number variations (CNVs) in 7/168 (4.2%) fetuses and variants of unknown significance (VOUS) in 15/168 (8.9%). Muscular and perimembranous VSDs were found in 53.6 and 46.4%, respectively. Clinically significant relevant subchromosomal aberrations were revealed in seven (9.0%) perimembranous VSDs compared with none in 90 muscular defects (P < 0.01). The median initial size of the defect in the muscular VSDs was 2.2(1.8–2.7) mm, as compared to that of 2.8 (2.2–3.2) mm in the perimembranous VSDs group (p = 0.000). In muscular vs. perimembranous VSDs, spontaneous closure occurred more frequently and earlier [40.0 vs. 15.4% in utero (p = 0.000), 61.1 vs. 30.8% at 1-year (p = 0.000), and 75.6 vs. 42.3% at 2-year (P = 0.000)]. Postnatal surgical closure was warranted in 4/90 (4.4%) of the infants with muscular VSDs, as compared to 29/71 (40.8%) with perimembranous defects (p = 0.000). Furthermore, isolated muscular type VSD, smaller defect size, and maternal age of less than 35 years are all positive predictors of spontaneous closure of the defects.

Conclusion

This study highlighted the value of microarray for unbalanced subchromosomal abnormalities in fetuses with isolated VSD, particularly in the perimembranous defects. The detection of an isolated muscular VSD prenatally may be considered a benign or likely benign finding; in contrast, for perimembranous VSD, a prenatal CMA should be offered.

Prenatally diagnosed isolated perimembranous ventricular septal defect: genetic and clinical implications

Objective

To evaluate the incidence of chromosomal aberrations and the clinical outcomes following the prenatal diagnosis of isolated perimembranous ventricular septal defect (pVSD).

Methods

This retrospective study was composed of a cohort of pregnant women whose fetuses were diagnosed with isolated pVSD. Complete examinations of the fetal heart were performed, as well as a postnatal validation echocardiography follow‐up at 1 year of age. The collected data included: spontaneous closure of the pVSD, need for intervention, chromosomal aberrations and postnatal outcome.

Results

Fifty‐five pregnant women were included in the study. 34/55 (61.8%) of the fetuses underwent prenatal genetic workup which revealed no abnormal results. No dysmorphic features or abnormal neurological findings were detected postnatally in those who declined a prenatal genetic workup during the follow‐up period of 2 years. In 25/55 of the cases (45.4%), the ventricular septal defects (VSD) closed spontaneously in utero, whereas in 17 cases of this group (30.9%) the VSD closed during the first year of life. None of the large 3 VSDs cases (>3 mm), closed spontaneously.

Conclusion

Prenatally isolated perimembranous VSD has a favorable clinical outcome when classified as small‐to‐moderate size, children in our cohort born with such findings had no macroscopic chromosomal abnormalities.

What's already known about this topic?

The detection rates of perimembranous ventricular septal defect (PVSD) is improving in recent years.

What does this study add?

We found no evidence that isolated pVSD is a significant risk factor for chromosomal anomalies.

Isolated small and medium size (<3 mm) PVSD's have a favorable clinical outcome with resolution either prenatally or within the infant's first year of life.

Prenatal diagnosis of isolated perimembranous ventricular septal defects undergoing primary surgical repair in infancy

OBJECTIVE

We retrospectively analyzed our center's experience with the prenatal diagnosis of isolated perimembranous ventricular septal defects that underwent primary surgical repair in infancy.

METHODS

We identified patients born in Southern Nevada, between October 2012 and October 2020, with prenatal care that underwent surgical closure of an isolated large perimembranous ventricular septal defect between 1 and 12 months of age. The description at surgery defined ventricular septal defect morphology. We included only those with situs solitus, levocardia without dextroposition, and without any other cardiovascular abnormality. We analyzed prenatal detection rates for each of the eight years.

RESULTS

We identified 81 patients. Of the 81, 35 (43%) had trisomy 21. We identified no other aneuploidies in those that underwent surgical repair; however, 1 had a 15q13.3 deletion syndrome, and 1 had a 22 q11.2 deletion syndrome. Of the 81, 27 (33%) overall were prenatally diagnosed. Increasing prenatal detection rates strongly correlated with time (R = 0.92, p = .002).

CONCLUSIONS

Trisomy 21 is common in isolated perimembranous ventricular septal defects undergoing primary repair in infancy. Further, prenatal detection rates significantly improved over time, up to 65% detection in the current years.

Prenatally detected isolated ventricular septum defects and the association with chromosomal aberrations-A nationwide register-based study from Denmark

OBJECTIVE

To evaluate the association between prenatally detected isolated ventricular septum defects (VSDs) and chromosomal aberrations in a nationwide study in Denmark.

METHOD

Nationwide, register-based study with prospectively collected data including all singleton pregnancies from 2014-2018. From the Danish Fetal Medicine Database, we retrieved data on maternal characteristics, first-trimester biomarkers, pre- and postnatal diagnoses, genetic test results, and pregnancy outcomes. VSDs were considered isolated in the absence of other malformations or soft markers, and with a low first-trimester risk assessment for trisomies 21, 18 and 13. All cases of an isolated VSD with a chromosomal anomaly were audited. The genetic tests included karyotyping and chromosomal microarray.

RESULTS

We retrieved data on 292 108 singleton pregnancies; 323 registered with a prenatally detected VSD and 697 with a VSD detected postnatally (incidence of 0.35%). Only 1/153 (0.7%, 95% CI 0.02;3.6%) of the isolated prenatally detected VSDs had an abnormal genetic test result (del (8)(q23.1)). Moreover, they had a lower free β-hCG MoM (0.9 MoM vs 0.99 MoM, P = 0.02), and were more likely born small for gestational age (SGA), defined as birthweight 2 or more SD below the mean, compared with the control population (5.2% vs 2.5%, P = 0.03).

CONCLUSION

We found a prevalence of chromosomal aberrations of 0.7% in fetuses with a prenatally detected isolated VSD. Moreover, we found an association between isolated VSDs and a larger proportion being born SGA.

What have we learned from 691 prenatal chromosomal microarrays for ventricular septal defects?

INTRODUCTION

Ventricular septal defect (VSD) represents the most common type of congenital cardiac anomaly, affecting more than 1 in 300 live births. The objective of this study was to examine the incidence and nature of abnormal chromosomal microarray analysis (CMA) results in a large cohort of pregnancies with VSD.

MATERIAL AND METHODS

Data acquisition was performed through the Ministry of Health computerized database. All CMA results performed due to VSD during 2013-2017 were included. The rates of clinically significant CMA results of cases with isolated and non-isolated VSD were compared with two control populations-a systematic review of 9272 pregnancies and a local cohort of 5541 fetuses with normal ultrasound.

RESULTS

Overall, 691 CMA analyses performed due to a sonographic indication of VSD were detected. Of 568 pregnancies with isolated VSD, eight (1.4%) clinically significant copy number variants were detected, a nonsignificant difference compared with low risk pregnancies. Of the 123 pregnancies with non-isolated VSDs, 18 (14.6%) clinically significant CMA results were detected, a considerably increased risk compared with control pregnancies. Karyotype-detectable anomalies constituted 12 of the 18 abnormal CMA results in non-isolated VSD group (66.7%), a significantly higher proportion compared with 2 of 8 (25%) in isolated VSD cohort.

CONCLUSIONS

The outcomes of our study, representing the largest number of CMA results in pregnancies with VSD, suggest that the rate of abnormal CMA findings in isolated VSD does not differ from pregnancies with normal ultrasound. This observation is true for populations undergoing routine common trisomy screening tests and early sonographic evaluation, as well as widely available non-invasive prenatal screening. Conversely, CMA analysis yields a high detection rate in pregnancies with non-isolated VSD. Our results question the recommendation to perform invasive prenatal testing for CMA in pregnancies with isolated VSD.