Over the past decade, specialized echocardiographic techniques have evolved as a major component of the noninvasive diagnosis of Pediatric and fetal heart diseases. Fetal echocardiography provides an opportunity to correlate anatomic and electrophysiologic information and cardiac haemodynamics and thus helps to determine the need and type of therapeutic intervention (1). New high-resolution transvaginal probes have been used to evaluate fetal heart in the early first and second trimester of pregnancy, between 10-15 weeks of gestation (2). With ongoing research in fetal cardiac surgery and fetal intervention, the need for consistent and accurate prenatal diagnosis of congenital heart diseases will become even more important. This article provides a brief overview of the indications and applications of fetal echocardiography and highlights the protocol of treatment in antenatally detected congenital heart diseases.

Congenital heart disease (CHD) is the most common severe congenital abnormality with an incidence of 8.8 in 1000 live births (3). Approximately half of these are major requiring intervention in the neonatal period or infancy which are associated with a high degree of mortality and morbidity even when corrected. The other half are comprising of minor lesions such as ventricular septal defects (VSD), atrial septal defects (ASD) and patent ductus arteriosus (PDA), etc.
In the Indian setting, the above figure translates into approximately 50-75,000 children being born with a major CHD every year. Lack of availability and affordability of specialized care except in certain pockets and relative high yield of prenatal diagnosis of CHD in setting of abnormal obstetric scan, stresses the need for fetal heart screening in routine obstetric scan.
A number of risk factors (Table-I) have been identified as possible contributory factors in the development of congenital heart defects, though it is paradoxically true that majority of fetuses with CHD have no identifiable risk factors (2).

Table -I: Risk factors for congenital heart disease.

Fetal :

• Chromosomal abnormalities
  
  
• Extracardiac anatomic abnormalities
  
  
• Non-immune hydrops Fetalis
  
  
• Fetal cardiac arrhythmias
  
  
• Suspected cardiac anomaly on routine ultrasound
  
  

• Family history of CHD
  
  
• Maternal metabolic disorders
  
  
• Maternal teratogen exposure
  
  

The decisions for most simple lesions if detected antenatally, which include small ventricular septal defect, atrial septal defect in the region of fossa ovalis, mild valvular stenosis, mild coarctation of aorta are routine antenatal care with normal delivery and a follow up of the child in neonatal or early infancy period. These defects usually escape detection and are the major limitations of fetal echocardiography. However, it is imperative here to stress that the potential parents should be reassured about the relative benign nature of these congenital heart lesions and thus allay their anxiety. Some of these lesions may be progressive during the childhood period, which would require routine follow-up, but most of them are easily amenable to interventional and surgical correction.

All complex congenital lesions detected antenatally need further evaluation to detect associated chromosomal anomalies and severe non-cardiac lesions as the management strategies and prognosis risk greatly varies if they are compounded. In most cases with multiple cardiac lesions and above mentioned associated factors, the choice of therapeutic termination of pregnancy is offered to the parents (if surgical correction for that cardiac lesion is not easily available, affordable and where there is a poor prognosis for long term survival (3).