Characterization and natural history of ventricular septal defects in the fetus

Objective To characterize and describe the evolution of ventricular septal defects (VSD) from intra-uterine diagnosis to infancy in a population of fetuses with isolated defects. Methods Sixty-eight fetuses with isolated VSD represented the study population. Of these, 28 underwent termination of pregnancy, 14 died in utero or after birth and 26 reached 1 year of age. In this population the following variables were evaluated: presence of extracardiac or chromosomal anomalies, site and size of the defect, pregnancy outcome. These variables were assessed against closure of the VSD up so 1 year of age. Necropsies were available for all fettuses following termination of pregnancy. All surviving neonates were followed up directly or by telephone until documented echocardiographic closure of the defect or until 1 year of age. Results There was a significant correlation between type of VSD and type of aneuploidy (P < 0.001). A total of 26 surviving fetuses reached 1 year of age: 46.1% (n = 12) of all defects closed in utero, 23.1% (n = 6) closed during the first year of life and 30.8% (n = 8) remained patent. Only three (15.8%) of the 19 VSDs <3 mm remained patent in comparison with five (71.4%) of the seven defects > 3 mm (P <0.05). None of the malalignment VSDs closed, in comparison to 69% of the peri-membranous and 60% of the muscular defects. Conclusion Ventricular septal defect can undergo spontaneous closure during intra-uterine life and this process depends upon the site and the size of the defect. These data may provide useful additional information to aid prenatal counseling.