An excellent imaging tool in the prenatal diagnosis and ongoing evaluation of congenital heart defects, fetal echocardiography is indicated in a selected population at increased risk compared with the general population. For certain "soft markers" of fetal congenital heart defects, ambiguity in the indications for fetal echo may result in a high referral rate, but low yield of congenital heart disease. Here, we critically examine 4 conditions, 2 maternal and 2 fetal: maternal gestational diabetes, advanced maternal age, isolated echogenic focus, and single umbilical artery. This critical review reveals that more prospective population-based studies with higher power and minimal bias need to be performed to establish the absolute risk of congenital heart defects in a selected population compared with that of the general population. Nonetheless, our analysis indicates that the absolute risk of congenital heart defects associated with each of these markers is low.
Target audience: Obstetricians & Gynecologists, Family Physicians
Learning objectives: After completion of this article, the reader should be able to define which patients should be referred for fetal echocardiography based on known risks, distinguish between relative and absolute risks for fetal congenital heart disease, and summarize fetal anomaly risks for women with altered glucose metabolism.