Isolated ventricular septal defects detected by color Doppler imaging: evolution during fetal and first year of postnatal life.

OBJECTIVE: To evaluate the development during gestation and up to 1 year postnatally of isolated small ventricular septal defects (VSDs) not visible by gray-scale imaging and detected only on color Doppler fetal echocardiography.

METHODS: This was a retrospective analysis of 146 fetuses with isolated VSDs detectable only on color Doppler echocardiography. Complete sequential gray-scale, color Doppler and spectral Doppler examination of the fetal heart were performed. The following variables were documented: site of the VSD, presence of extracardiac or chromosomal anomalies, outcome of the pregnancy and evolution of the defect up to 1 year postnatally.

RESULTS: A total of 113 fetuses reached their first year of postnatal life, 23 pregnancies were terminated, there were three stillbirths/neonatal deaths, and seven were lost to follow-up. It was observed that 32.7% (n = 37) of all defects in neonates alive after 1 year closed in utero, 44.3% (n = 50) of defects closed spontaneously within the first postnatal year, and 23.0% (n = 26) of defects did not close. In all, a comparable number of perimembranous and muscular septal defects closed spontaneously in utero and during the first year of postnatal life. Among 35 fetuses with extracardiac anomalies 51.4% (n = 18) were euploid.

CONCLUSION: Small VSDs, detectable only by color Doppler echocardiography, show a high spontaneous intrauterine and postnatal closure rate. These findings might be of value for prenatal parental counseling.