Population screening of fetal cardiac abnormalities through prenatal echocardiography in low-risk pregnancies in the municipality of Porto Alegre.

OBJECTIVE To study the morphological and functional abnormalities of the fetal cardiovascular system detectable through ultrasonography. METHODS The study comprised 3,980 fetuses of pregnant women with no obstetrical or cardiological risk in the municipality of Porto Alegre, who, from July 1996 to November 2000, underwent echocardiography for screening fetal cardiovascular malformations. The examinations consisted of 4-chamber and right and left ventricular outflow tract echocardiographic views. RESULTS One hundred and three diagnoses of fetal cardiovascular abnormalities were established, corresponding to 2.58% (103/3,980) of the population studied, or 25.8/1000, of which 47 represented morphological and functional changes in the fetal heart with an overall prevalence of 11.8/1000 (47/3,980), and 56 showed changes in refringence (golf ball). Three false negative and no false positive results increased the overall prevalence to 12.5/1000 (50/3,980), or 26.6/1000 (106/3,980), when the refringence changes were also included. CONCLUSION The detection of cardiovascular malformations still in the intrauterine period, aiming at perinatal planning, is possible, which confirms the international experience. Implantation of cardiovascular malformation screening into the routine care network of obstetrical ultrasonography is suggested.