Congenital heart abnormalities are the most common birth defect among all geographic regions and racial and ethnic backgrounds. With advancements in imaging technology, fetal echocardiography provides the opportunity to diagnose complex cardiovascular conditions from the first trimester of pregnancy onward. As a consequence, the prenatal diagnosis and management of fetuses with cardiac anomalies is emerging as an important component of health care worldwide. Examination of the fetal heart and care of fetuses with abnormalities in the cardiovascular system have evolved considerably over the past two decades. In the past, the role of the physician examining a fetus was to provide a basic and often limited anatomic cardiac diagnosis, with the primary goal of informing families and providers regarding the expected postnatal structural disease and anticipated postnatal interventions. Care of the mother and fetus was based on a premise that nothing could be done in utero and that what was understood to be true of postnatal disease also applied to fetuses. The field of fetal cardiology has progressed in recent years, going beyond basic recognition of structural abnormalities to now include precise and detailed serial assessment of cardiac structure, function, and rhythm through gestation, offering opportunities for the development of in utero management strategies and intervention in select cases. In addition, prediction of the effect of the transitional circulation on fetuses with cardiac disease has become a key aspect of care, with creation of strategies for specialized perinatal management in the delivery room for severe defects that offer the promise of improved outcomes for cases in which cardiovascular compromise is anticipated.
Paralleling advances in clinical care, research in the field has also experienced a great deal of growth. A review of the medical literature through PubMed shows a substantial increase in the number of annual publications relating to fetal echocardiography and fetal cardiology ( Figure 1 ). The first report on the use of ultrasound to assess the fetal heart was published in 1969. Early advancements in the field occurred slowly, but by the mid-1990’s, the number of new publications had reached approximately 150 per year. In the current era, because of rapid improvements in imaging technology, including the use of high-resolution probes, three-dimensional imaging, and technologies such as Doppler tissue imaging and strain assessment, and the establishment of fetal cardiac intervention protocols for specific congenital heart defects, the field seemingly has hit its prime, with the number of publications approaching 350 to 400 in recent years.
The concept of the fetus as a patient requiring medical expertise for proper care and management is now established. For the discipline to continue to evolve, the next set of challenges relate to expanding the investigation of the fetal circulation in conditions of health and disease, including the fundamentals of fetal cardiac function and the variables that relate to the in utero progression of cardiovascular disease. Furthermore, the capacity to alter the natural history of fetal cardiac disease through in utero treatment is also possible for a growing set of conditions. A major limitation faced by those who study fetuses with cardiovascular disease is that many of the conditions are relatively uncommon. In addition, variable treatment strategies and approaches among centers lead to limited experiences, bias, and a weak evidence base for clinical practice. These factors impair the ability to advance knowledge in the field. Collaboration among investigators and institutions is therefore essential to facilitate discovery and innovation while collecting the evidence required to improve care for fetuses with cardiovascular abnormalities.
In recent years, there has been a coming together of subspecialists who care for pregnant women and their fetuses with cardiovascular abnormalities. Formation of a multidisciplinary fetal heart society was first suggested in an article published in 2008 and then mentioned again in an editorial in 2014. In 2013, both the American Institute of Ultrasound in Medicine and the International Society of Ultrasound in Obstetrics and Gynecology modified their guidelines for fetal echocardiography, including in the writing group specialists across the disciplines of obstetrics, radiology, genetics, and pediatric cardiology. In 2014, the first American Heart Association statement paper for the diagnosis and treatment of fetal cardiac disease was published in Circulation , with a writing group spanning the specialties of pediatric cardiology, obstetrics, cardiovascular surgery, and nursing. Several investigators have taken advantage of using multicenter retrospective data to study rare diagnoses, including Ebstein’s anomaly and tricuspid valve dysplasia and tetralogy of Fallot with absent pulmonary valve (unpublished results), by soliciting participation via word of mouth and e-mail. In a more organized manner, the International Fetal Cardiac Intervention Registry was created as a voluntary database for fetal cardiac intervention so that procedures could be better evaluated. Finally, the first international collaborative randomized controlled trial in fetal cardiology for the assessment of in utero treatment of fetal arrhythmias was successfully funded, offering the promise of identifying the most effective strategies for in utero treatment of life-threatening fetal arrhythmias. The timing is now right for the creation of an organized society, a formal relationship bridging the subspecialties of pediatric cardiology, obstetrics and maternal fetal medicine, and all relevant disciplines, with the objective of bringing together all interested clinicians and scientists in the common goal of advancing the field of fetal cardiac medicine.
The Fetal Heart Society (FHS) was incorporated as a nonprofit organization in October 2014 with the overarching goal of advancing the field of fetal cardiovascular care and science through collaborative research, education, and mentorship ( Figure 2 ). The mission of the FHS according to its bylaws is as follows:
to advance the cause of research and education relating to the field of fetal cardiology and other reasonably related medical or scientific pursuits;
to promote and encourage the development and advancement of the field of fetal cardiovascular diagnosis, management, and therapy;
to promote the establishment of mutually beneficial relationships among the FHS members to enable sharing of ideas and research collaboration;
to foster and facilitate multicenter research and collaboration; and
to advance the field of fetal cardiovascular science and clinical practice by establishment of a fetal cardiovascular research collaborative within the society’s auspices.