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.