Fetal echocardiography

Abstract

Since the first report of fetal echocardiography in 1972 by Winsberg, several advances in ultrasound technology have occurred allowing detailed evaluation of cardiac anatomy in the second trimester fetus. Fetal echo is indicated in high risk pregnancies where the chances of fetus having a congenital heart disease (CHD) are likely to be high e.g., in fetus with extracardiac anomalies picked up on obstetric ultrasound, those with a history of CHD in family, maternal diabetes (especially insulin dependent), maternal connective tissue disorder etc. The reported sensitivity of fetal echo has ranged from 4-96% in various series depending upon the equipment, level of training, study design and examination technique. Although many CHD can be detected in four chamber view, an important group malformations that would need early intervention are likely to be missed. Hence a detailed echocardiographic examination including the outflow views must be done. Defects like atrial septal defect and patent ductus arteriosus cannot be diagnosed in fetal echo, as these are part of normal fetal physiology. Other CHD like coarctation of aorta, small ventricular septal defects, mild valvular stenosis, partial anomalous pulmonary venous drainage are also difficult to diagnose. Ultrasound assessment of fetus, however, has a clear role in the diagnosis, monitoring and management of fetuses with sustained arrhythmias. Prenatal diagnosis of CHD helps in planning the optimal management of the baby e.g. a fetus with a ductus dependent lesion can be planned to be delivered in a tertially care centre for stabilisation and early initiation of prostaglandin therapy to avoid acidosis and organ damage. Future of fetal medicine lies in fetal cardiac surgery for which echocardiography will play a very important role.

Fetal cardiac cine magnetic resonance imaging in utero

“…Currently, prenatal screening for CHDs is performed with ultrasonography 6 . However, the sensitivity of fetal echocardiography varies widely, depending on equipment, national screening policies, level of training, examination practice and the population screened 7 . As a result, in many cases, CHDs remain undetected until birth.…”

Accuracy of fetal echocardiography in the routine detection of congenital heart disease among unselected and low risk populations: a systematic review

“…The sensitivity for correct diagnosis of babies for congenital heart disease defects was higher among the unselected population than among the low risk populations. Indeed, the sensitivities for detecting congenital heart disease among the unselected population was comparable to high risk populations 10,23–25 ; however, the potential for ascertainment bias and the choice of reference standard limits the validity of this finding. Because of the substantial variation in study characteristics, it was also difficult to disentangle which potentially important clinical factors such as scanning regime, operator skill and equipment, could attribute to the higher sensitivities.…”

“…Fetal echocardiography has been used as a diagnostic tool to identify congenital heart disease in high risk groups for some years, 20,21 and has been found to have sensitivities ranging from 60% to 100% 10,22–24 . Its routine use in unselected obstetric populations including those at low risk is uncommon and more controversial 19,25–27 . Against this background, a systematic review was conducted to determine the accuracy of fetal echocardiography to detect congenital heart disease to inform whether it should be included in a routine 20‐week anomaly scan for an unselected obstetric population including newborn at low risk for developing cardiac defects.…”

Characterization of fetal cardiac structure and function detected by echocardiography in women with normal pregnancy and gestational diabetes mellitus

“…Indeed, fetal echocardiography performed at an adequate timing in pregnancy and by operators with specific expertise and skills achieves a high rate of diagnostic efficacy for fetal congenital heart defects(Bhat and Sahn, 2004; Small and Copel, 2004). Less clear is the value of echocardiography in fetuses with cardiac dysfunction (Srinivasan, 2000).…”