Correlation between types of Ventricular Septal Defect and chromosomal abnormalities in Low-Risk Non-Invasive Prenatal Testing: A Retrospective Study

Abstract

Objective The purpose of this study was to find the association between different types of ventricular septal defect (VSD) and chromosomal abnormalities in the low-risk setting of non-invasive prenatal testing (NIPT), as well as to analyze the prognosis of fetuses with different types of VSD. Methods Cases with prenatal diagnosis of fetal VSD by amniocentesis were collected from May 2017 to May 2022 at Tianjin Central Obstetrics and Gynecology Hospital. Patients with high risk of prenatal NIPT, including chromosomal number abnormalities, fragment deletions or duplications, and polymorphisms, were excluded from the study. The data collected included ultrasound classification of VSD, prenatal NIPT results, copy number variations (CNVs) results, and neonatal outcomes. Results This study examined 74 cases, consisting of 45 isolated VSDs (8 of which were muscular septal defects and 37 non-muscular septal defects) and 29 non-isolated VSDs (10 associated with intracardiac structural anomalies and 19 with extra-cardiac structural anomalies). The results showed that the prevalence of pathogenic CNV was lower in isolated VSDs than in non-isolated VSDs in a low-risk NIPT condition (χ2 = 9.344, P = 0.002). There was no significant disparity in the incidence of pathogenic CNV between VSDs with intracardiac and extra-cardiac structural anomalies (P = 0.541). Additionally, VSDs associated with intracardiac structural anomalies had the highest rate of surgical intervention. Conclusions When NIPT is low-risk, isolated VSD does not raise the likelihood of fetal chromosomal defects. However, when VSD is non-isolated and combined with either intra- or extracardiac structural issues, the possibility of pathogenic CNV is significantly higher, and thus, invasive prenatal diagnosis is suggested. Additionally, it was observed that isolated muscular septal defects usually does not require surgical treatment, which provides a useful foundation for prenatal counseling regarding fetal VSD.