Knowing the fetal heart: What's the use?

Congenital heart diseases represent an important health problem due to its prevalence and consequences on perinatal morbidity and mortality. Over the past decade specialized echocardiographic techniques have evolved as the most informative modality for the non-invasive assessment of the fetal heart. As a result, the physician is now able to extend the care of children to include the fetus, thus permitting the timely diagnosis of cardiovascular disease, the arrangements for delivery in a tertiary centre and in some situations monitoring in utero therapy for certain disease states. Congenital malformations of the cardiovascular system are among the leading causes of morbidity and mortality in infancy and childhood affecting about 8 out of 1000 liveborn infants. The prevalence is likely to be substantially grater in the fetal population because some cardiac anomalies are associated with spontaneous intrauterine demise. The importance of this group of lesions is even more apparent when we consider its association with extracardiac malformations (25-30 70) and chromosomal abnormalities (they are responsible for 5 70 of cardiac defects in newborns). Therefore prenatal detection of CHIC is highly relevant for good prenatal and perinatal car. Most cardiac defects will develop within the first eight weeks of gestation during the period of cardiac embryogenesis, which comprises cardiac looping, division of the atrioventricular canal, and rotation of the conotruncus. Cardiac morphogenesis occurs between 15 weeks and term, and is the time during which the heart changes in shape, function and size. During this vulnerable period some cardiac defects may progress in severity later in utero. Therefore, prenatal diagnosis of cardiac malformations encompasses the recognition of abnormal anatomy (most of which occurs during embryogenesis) as well as recognition of aberrant growth patterns (which occur during morphogenesis).