An ethnic predilection for fetal echogenic intracardiac focus identified during targeted midtrimester ultrasound examination: A retrospective review

BACKGROUND: Echogenic intracardiac focus (EIF) has been identified as a common ultrasound finding in association with fetal aneuploidy. Little is known about the association of this soft marker aneuploidy in various ethnic groups. Although it is commonly thought Asians in general have a higher incidence of EIF, it is unknown whether this also applies to Japanese as a subpopulation. The purpose of this study is to determine the antenatal incidence and postnatal significance of EIF observed during sonography in Japanese patients. METHODS: A cohort of Japanese patients who underwent ultrasound screening from 1997 to 1999 in the ultrasound unit at the New York University School of Medicine was identified. Variables included age, gestational age, serum markers, and the presence or absence of aneuploidy. Patients with first degree paternal or maternal Japanese ancestry were included for analysis. Examinations were performed between 14 and 24 weeks gestation. The prevalence of EIF was calculated. The control group was based on previously published data in the U.S (7.3% prevalence). RESULTS: A total of 154 subjects were identified, 148 were available for final analysis. Twenty-two fetuses had an EIF, 19 (86.4%) left-sided, 3 (13.6%) right-sided. Seventeen patients had other sonographic markers associated with aneuploidy. The mean maternal age at diagnosis was 30.7 +/- 3.9 years and the mean gestational age was 19.8 +/- 1.6 weeks. The prevalence of EIF was 14.8%. Compared to published population prevalence, there was a statistically significant difference (p < 0.005). No abnormal karyotypes were found. CONCLUSION: Asians of Japanese origin may have a higher prevalence of echogenic intracardiac foci, thus affecting the positive predictive value of this sonographic marker for aneuploidy.