Risk factors for cardiac malformations detected by fetal echocardiography in a tertiary center

OBJECTIVE: Fetal echocardiography accurately detects congenital cardiac anomalies, but it is costly, time-consuming, and requires highly-skilled operators. Our aim was to define those patients for whom fetal echocardiography is justified. METHODS: The files of 1696 consecutive patients who underwent second- to third-trimester fetal echocardiography at our tertiary center between 1997 and 1999 were reviewed for reason for referral, echocardiography diagnosis, and pregnancy outcome. RESULTS: The patients were categorized by reason for referral into high-and low-risk groups. The high-risk group included 662 patients (39%) with fetal risk factors, 178 (10.5%) with maternal risk factors and 279 (16.5%) with poor obstetric history. The remaining 577 women (34%) were considered low-risk population. These included 282 self-referred women (due to maternal anxiety) who served as control group, 78 women who were referred because of a suspected cardiac malformation on routine second-trimester ultrasound, and 213 women who were referred because of failure to view the heart on second-trimester ultrasound. In 46 women, cardiac anomalies (2.7%) were detected prenatally and confirmed postnatally; most of them (41/46, 89%) were in the low-risk population. Abnormal cardiac findings on second-trimester ultrasound and a diagnosis of a single umbilical artery made the most significant contribution to the detection of cardiac abnormalities (p < 0.001 and p = 0.02, respectively). CONCLUSIONS: Most fetal cardiac malformations occur in the low-risk population. Abnormal view of the fetal heart on routine second-trimester screening is highly predictive of congenital cardiac anomalies.