Early fetal echocardiography: Experience of a tertiary diagnostic service

Background: There is a growing body of evidence that most of the major cardiac abnormalities can be diagnosed at 14-15 weeks of gestation. We present our experience of early fetal echocardiography.

Materials and methods: This is a retrospective cohort study of women referred for early fetal echocardiography at 13-16 weeks of gestation at Royal Prince Alfred Hospital and Sydney Ultrasound for Women between August 2011 and March 2014. Findings of early fetal echocardiography, details of subsequent ultrasound examinations and pregnancy outcome were recorded.

Results: Early fetal echocardiography was performed in 400 euploid fetuses at a mean gestational age of 15(+2) weeks. 85% of women were referred for increased nuchal translucency. 383/400 (96%) women had both normal early and late fetal echocardiograms 15/400 (3.7%) were found to have a cardiac defect at early fetal echocardiography, including 14 major and one minor abnormality. Two additional minor cardiac defects were diagnosed at later antenatal ultrasounds. One case, defined as being normal antenatally, was found to have a minor cardiac abnormality post-natally. Eight (57%) women whose fetus had a major cardiac defect chose to terminate the pregnancy. In the pregnancies that continued, the sensitivity and specificity for major cardiac defects was 100%, 95% CI (0.98-1.00).

Conclusion: Early fetal echocardiography is feasible and highly sensitive and specific in experienced hands. The high specificity facilitates early reassurance of those women assessed at increased risk for fetal cardiac malformations.