PROSPECTIVE EVALUATION OF THE ANTENATAL INCIDENCE AND POSTNATAL SIGNIFICANCE OF THE FETAL ECHOGENIC CARDIAC FOCUS - A CASE-CONTROL STUDY

OBJECTIVE: We evaluated the antenatal incidence and postnatal signific ance of echogenic cardiac foci observed during antenatal ultrasonograp hy. STUDY DESIGN: During a 4-month period, all women undergoing dating ultrasonography between 16.0 and 24.9 weeks' gestation at one referra l center were prospectively evaluated for an echogenic cardiac focus d uring an epical four-chamber view of the heart. Referrals for maternal or fetal complications were excluded. Postnatal echocardiography was performed for those identified with positive findings. Controls were s elected from among normal subjects in the general group for comparison with the study group. RESULTS: Five hundred six consecutive fetuses w ere evaluated at a mean +/-SD gestational age of 20.6 +/- 1.6 weeks. T here were 25 (4.9%) fetuses found to have echogenic cardiac focus (lef t ventricle = 19, right ventricle = 6). Echocardiography was performed between 0.3 and 20.1 weeks postdelivery. After birth, 12 echogenic le ft ventricle papillary muscles and three echogenic left ventricle chor dae were identified; there were no postnatal right ventricle findings. There were no cases of intracardiac tumor or myocardial dysfunction; one neonate had minor structural malformations. There were no signific ant differences in maternal age, gravidity, parity, gestational age at ultrasonography, gestational age at delivery, or 5-minute Apgar score s, A significant difference was observed in birth weight between the c ontrol (n = 50) and study (n = 25) groups (3465 +/- 501 gm vs 3124 +/- 589 gm; p = 0.002). This difference persisted after correcting for ge stational age, although all infants in both groups born after 37.0 wee ks weighed >2500 gm. CONCLUSIONS: The incidence of echogenic cardiac f oci during routine midtrimester ultrasonography is 4.9%. As an isolate d finding, the echogenic cardiac focus may be associated with a statis tically significant but clinically insignificant decrease in birth wei ght. Because of these findings, we consider an isolated echogenic card iac focus in a patient al low risk for cardiac abnormalities a variant of normal, which does not warrant follow-up clinical evaluation.