SMFM Clinical Practice Guidelines Isolated echogenic intracardiac focus Society of Maternal Fetal Medicine with the assistance of Krista Moyer MGC, James D. Goldberg MD Published in Contemporary OB/GYN / June 2013

Definition An EIF is a small echogenic area appearing within the fetal cardiac ventricle that has a sonographic brightness equivalent to that of bone (Figure). It was first described in 1987 and is most commonly left-sided, although it may be present in either or both ventricles. EIF is believed to represent a microcalcification of the papillary muscle. Other specular reflections in the heart may mimic an EIF. To avoid this, it is important to image the suspected EIF in multiple planes. 

Clinical Implications An EIF is not considered a structural or functional cardiac abnormality. It has not been associated with cardiac malformations in the fetus or newborn. The only reported clinical implication is an increased risk of trisomy 21. When an EIF is identified, an experienced provider should perform a detailed fetal anatomic survey to assess for the presence of structural malformations and other sonographic markers of aneuploidy. In addition, the physician should perform an assessment of other risk factors, including maternal age, results of other screening or diagnostic tests, and family history. Most EIFs are isolated and occur in otherwise low-risk pregnancies.

When an isolated EIF is detected, how does counseling differ for women at increased risk for fetal aneuploidy and for women with normal aneuploidy screening results? All patients, regardless of ultrasound findings, should be offered prenatal screening for aneuploidy and should have the option of invasive diagnostic testing. Counseling for a woman after prenatal identification of EIF should be guided by presence of other sonographic markers or structural abnormalities, maternal serum screening for risk of Down syndrome (if performed), and maternal age. If an isolated EIF is detected in a woman who has already had an invasive diagnostic test—and the fetal karyotype is known—she can be reassured that the finding is considered a normal variant.

When an isolated EIF is detected, how does counseling differ for women at increased risk for fetal aneuploidy and for women with normal aneuploidy screening results? Numerous studies have described the association between EIF and aneuploidy, specifically Down syndrome. Meta-analyses of studies conducted primarily in high-risk pregnancies reported that the risk of trisomy 21 was increased 1.8- to 5.4-fold by the finding of an isolated EIF. Recently, another meta-analysis similarly identified a 2.9 likelihood ratio (LR) for isolated EIF, when defined as no major abnormalities and no evidence of ventriculomegaly, increased nuchal skinfold thickness, echogenic bowel, pyelectasis, short humerus, or short femur. A suggested method of risk assessment is to multiply the patient’s a priori risk (based on maternal age or screening) by a published likelihood ratio such as 2.9 to generate a modified risk. In women with serum screening indicating an increased risk of trisomy 21 following risk modification, genetic counseling may be helpful. Noninvasive prenatal testing (NIPT) may be a reasonable option for women who are concerned about the procedure-related risk of pregnancy loss. If the NIPT result is negative, an isolated EIF may be considered a normal variant because of the extremely low residual risk of trisomy 21. These women, however, should still have the option of an invasive diagnostic test.

Conclusion Therefore in a woman with a negative aneuploidy screen for Down syndrome (either first- or second-trimester screening) and no visualized fetal structural abnormalities or other aneuploidy markers on a detailed ultrasound, the provider has options. One option is to use the approach highlighted previously, using the LR for risk assessment. For these women at low risk of trisomy 21 pregnancies, other practitioners may consider an EIF a normal variant, and as a result of this perspective, provide no additional counseling or testing.1

How should a woman with an isolated EIF be followed throughout pregnancy? Because an isolated EIF does not represent a cardiac abnormality, fetal echocardiography is not needed and no specific follow-up is recommended. Follow-up should be performed based on the presence of other clinical indications or the results of the patient’s prenatal screening and/or diagnostic testing.

These slides are for personal, non-commercial and educational use only Disclaimer The practice of medicine continues to evolve, and individual circumstances will vary. This opinion reflects information available at the time of its submission for publication and is neither designed nor intended to establish an exclusive standard of perinatal care. This presentation is not expected to reflect the opinions of all members of the Society for Maternal-Fetal Medicine. These slides are for personal, non-commercial and educational use only

Disclosures This opinion was developed by the Publications Committee of the Society for Maternal Fetal Medicine with the assistance of Stanley M. Berry, MD, Joanne Stone, MD, Mary Norton, MD, Donna Johnson, MD, and Vincenzo Berghella, MD, and was approved by the executive committee of the society on March 11, 2012. Dr Berghella and each member of the publications committee (Vincenzo Berghella, MD [chair], Sean Blackwell, MD [vice-chair], Brenna Anderson, MD, Suneet P. Chauhan, MD, Jodi Dashe, MD, Cynthia Gyamfi-Bannerman, MD, Donna Johnson, MD, Sarah Little, MD, Kate Menard, MD, Mary Norton, MD, George Saade, MD, Neil Silverman, MD, Hyagriv Simhan, MD, Joanne Stone, MD, Alan Tita, MD, Michael Varner, MD) have submitted a conflict of interest disclosure delineating personal, professional, and/or business interests that might be perceived as a real or potential conflict of interest in relation to this publication.