Prospective Evaluation of Fetal Intelligent Navigation Echocardiography (FINE)(5D) Versus Conventional 2D Echocardiography in Comprehensive Fetal Cardiac Imaging in the Second Trimester of Pregnancy

Congenital malformations account for more than 20% of all infant deaths(CDC,2014), and congenital heart defects are the most common types of birth defects.

The prenatal diagnosis of major congenital heart defects remains a challenge. Publications by Acherman et al (Acherman RJ .et al) and Sklansky et al (Sklansky MS.et al)have found that approximately 35% of cardiac anomalies are detected prenatally, a frequency that is not substantially different from that documented by Wigton et al in 1993 (Wigton TR, et al) Advances in prenatal ultrasonography have improved prenatal care in recent decades and increased the detection of a large number of congenital malformations. The prenatal detection rate of congenital heart disease (CHD), however, has not shown the same increase as the detection of malformations in other fetal systems (DeVore GR, et al). CHDs are the most commonly overlooked lesions in prenatal screening programs(Garne E et al, Tegnander E et al). This causes concern as CHD represents the most common congenital malformation and is the leading cause of infant mortality in the first year of postnatal life(Garne E). It has been estimated that the prevalence of CHD is 4-8 per 1000 neonates(Hoffman JI et al).

Early detection and accurate prenatal diagnosis of CHD reduces neonatal morbidity and mortality rates by allowing provision of adequate prenatal and postnatal care(Randall P et al, Goncalves LF et al). Before viability is reached, parents can be counseled on the diagnosis, severity and prognosis. Furthermore, it provides parents with the opportunityto make informed decisions on the further course of pregnancy. The four-chamber view has become the standard approach in screening for CHD. Identification of the right and left outflow tracts markedly improves the detection rate of CHD(DeVore GR et al, Stumpflen I et al).

Prenatal detection of these anomalies has proved challenging. In a British study from 1999, Bull(AIUM 2013) reported on 4799 pregnancies affected by major congenital heart defects and found that the antenatal detection rate was only 24%. Lower detection rates were noted in centers that only assessed the 4-chamber view. Correspondingly, in an attempt to improve the antenatal detection rates of congenital heart defects, the American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, and International Society of Ultrasound in Obstetrics and Gynecology all have recommended that an attempt should be made to image the ventricular outflow tracts during the fetal anatomic survey.( Carvalho JS et al. , Bull C., AIUM 2003)

However, imaging of these outflow tracts can be challenging, and it is not clear that they can be typically obtained in generalized non-tertiary care settings. A 2007 study from the United States, which included 77,000 births, found that only 36% of major congenital heart defects were detected antenatally. It is not clear from the study whether outflow views were routinely obtained at all of the laboratories involved, but the study suggests that better detection rates could be achieved if outflow views were more routinely imaged.( Bull C. )