Is an isolated fetal cardiac echogenic focus an indication for fetal echocardiography?

Fetal Echocardiography for the General Pediatrician

Fetal echocardiography is now commonly used to assess fetuses for congenital heart disease. To care for their patients, it is important for the pediatrician to understand the utility of the test, the benefits, and the limitations of the results. This review outlines the indications, components, and limitations of fetal echocardiography with a focus on the care that the pediatrician provides to newborns and their families. An understanding of the fetal cardiac examination can assist the pediatrician in caring for patients with either normal or abnormal test results. The need for and timing of postnatal cardiology follow-up, and guidance on referral for fetal echocardiogram for future pregnancies are all critical roles that the pediatrician can play. Most importantly, an understanding of the limitations, including difficult-to-diagnose lesions, allows the pediatrician to maintain a high level of suspicion for cardiac defects regardless of fetal echocardiography findings. [Pediatr Ann. 2021;50(3):e121-e127.].

Intracardiac echogenic focus and its location: association with congenital heart defects

Purpose: Significance of intracardiac echogenic focus (ICEF) in the fetal heart remains controversial. We aimed to investigate whether the location of ICEF is associated with fetal cardiac structure defects (CSDs) in low-risk pregnant women. Materials and Methods: A retrospective cohort study was conducted. Singleton pregnancies with normal values of triple fetal serum markers were included. 758 of 9782 fetuses with ICEF were reviewed for involvement of three ICEF locations (left, right, and bilateral ventricles (BVs)) in CSDs. χ² or Fisher's exact test was performed for statistical analysis. Results: ICEF prevalence was 7.7% and its location was most frequently in the left ventricle (LV) (84.8%), followed by the BV (11.6%) and the right ventricle (RV) (3.6%). No statistically significant difference was found between the ICEF location and maternal age (χ² = 3.92, p-value = .1409). There were cardiac defects with an isolated echogenic focus in 24 of 758 fetuses (3.2%). Significant difference for CSDs was observed among groups of RV, LV, and BV (p-fisher = .0146). Conclusions: Significantly more CSDs cases were identified in fetuses with ICEF in RV. Further investigation is warranted to examine the histological characteristics of fetal echogenic focus in the RV.

Echogenic intracardiac foci and fetal cardiac anomalies: A review of cases from a tertiary care center in China

PURPOSE

To investigate the relationship between the location of echogenic intracardiac foci (EIFs) and fetal cardiac anomalies in our patient population.

METHODS

We performed a retrospective study of the clinical files of fetuses who underwent an echocardiographic examination at our fetal cardiac medical center from August 2010 to August 2016. Fetuses were grouped by EIF location (left ventricle [LV], right ventricle [RV], or bilateral ventricles [BVs]). The maternal age, reason for referral, and cardiac anomalies in the three groups were analyzed.

RESULTS

We enrolled 2647 fetuses with an EIF. Of these, 2498 (94.4%) were in the LV group, while 45 (1.7%) and 104 (3.9%) were in the RV and BV groups, respectively. Aneuploidy was found in 3 fetuses, and all of these had a left-sided EIF. Cardiac anomalies were found in 93/2498 (3.7%) fetuses with a left-sided EIF, 5/45 (11.1%) of those with a right-sided EIF, and 3/104 (2.9%) of those with bilateral EIFs. The prevalence of congenital heart disease was significantly higher in fetuses with a right-sided EIF than in those with left-sided or bilateral EIFs (P < .05).

CONCLUSIONS

Right-sided EIFs were more frequently associated with fetal cardiac anomalies than were left-sided or bilateral EIFs.

Evaluation of Referral Pattern for Fetal Echocardiography at a Tertiary Care Center in Northern India and Its Implications

OBJECTIVE

To determine the referral pattern for fetal echocardiography (FE) at our tertiary referral center for pediatric cardiac care in northern India. We also aimed to determine the incidence of CHD in each group and intend to highlight the need of identifying the various risk factors and appropriate timely referral of patients for detailed evaluation.

METHODS

This is a prospective study including 201 consecutive patients referred for fetal echo to our center. Data collected included referral indication, gestational age, maternal age, the gravida, and the final diagnosis after detailed fetal echo. Various indications that were evaluated included maternal diabetes (pre-gestational or gestational), echogenic cardiac nodule, abnormal four chamber on ultrasound, other extra-cardiac abnormalities detected on ultrasound, and twin pregnancies or IVF conceptions. Some women had opted for fetal echo electively and they were defined as self referral.

RESULTS

The mean gestational age of referral was 24 ± 5 weeks. Out of these, 196 had specific referral indication while five were self referrals. The most common indication for referral was echogenic cardiac foci. CHD was diagnosed in 38 (19 %) patients. Indication that yielded the highest number of CHD cases was cardiac abnormality on USG. The mean gestational age at referral in those detected to have CHD was 27 ± 4 weeks. The commonest CHD detected was tiny VSD, while most of the complex CHD's were diagnosed in those referred for cardiac abnormality on USG.

CONCLUSION

CHD detection is highest in those referred for abnormal cardiac imaging on USG, and hence a careful assessment of fetal heart during routine prenatal screening would increase the CHD detection markedly. Nuchal translucency needs to be measured accurately and those with value greater that 99th centile should be referred for FE. Mothers with pre-gestational diabetes should have a FE prior to 20 weeks to rule out CHD. A FE scan in third trimester is indicated in diabetic females (gestational and pre-gestational) if the glycemic control is poor evidenced by HbA1c > 6 %. Timely referral is absolutely essential so that appropriate counseling of the parents can be done.

Intracardiac echogenic focus and fetal outcome - review of cases from a tertiary care centre in Karachi, Pakistan

OBJECTIVE

To study the outcome in fetuses with intracardiac echogenic focus (ICEF) at the time of second trimester scan.

METHODS

All women with the sonographic findings of ICEF from January 2009 to December 2010 were included in this retrospective study.

RESULTS

ICEF were found in 71 out of 8226 screened (0.86%) women. Mean maternal age in the population was 26.9 ± 3.9 years. Foci were the isolated marker in 69 (97%) cases. In two cases there were additional findings of choroid plexus cysts. A fetal echocardiograph was done only in 13 (18.3%) patients. Majority of these pregnancies (95.7%) had a normal outcome. Postnatal echocardiograph was performed in 11 neonates (15%) out of which one had a small VSD, and in another case Tetralogy of Fallot was found. In addition, Pulmonary artery hypertension was diagnosed in one case. There was one intrauterine fetal demise and two neonatal deaths in this cohort.

CONCLUSIONS

The prevalence of ICEF was 0.86% in our study population. About 95.77% of these cases had an uncomplicated perinatal outcome. It was an isolated finding in almost all cases. These findings will be helpful in counseling parents in our setting.

Indications for fetal echocardiography high referral, low yield?

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.

Are intracardiac echogenic foci markers of congenital heart disease in the fetus with chromosomal abnormalities?

OBJECTIVE

To determine whether intracardiac echogenic foci (ICEF) are markers of congenital heart disease (CHD) in fetuses with chromosomal abnormalities.

METHODS

We identified all fetuses with chromosomal abnormalities undergoing targeted sonography at 17 weeks' to 21 weeks 6 days' gestation in a single perinatal center from January 1, 1994, to June 30, 2003. Offspring with and without CHD were compared for the presence or absence of ICEF.

RESULTS

Two (8%) of 25 fetuses with ICEF had CHD versus 38 (33.3%) of 114 fetuses without ICEF (P = .006). Similarly, 1 (5.5%) of 18 fetuses with trisomy 21 and ICEF had CHD compared with 16 (37.2%) of 43 fetuses with trisomy 21 without ICEF (P = .009).

CONCLUSIONS

Intracardiac echogenic foci in fetuses with chromosomal abnormalities, including those with trisomy 21, are not useful markers for CHD.

An isolated echogenic heart focus is not an indication for amniocentesis in 12,672 unselected patients

OBJECTIVE

To evaluate the risk of Down syndrome in fetuses with a heart echogenic focus using the Bayes theorem and likelihood ratios in an unselected population.

METHODS

We prospectively evaluated 12,672 second-trimester sonographic features and extracted and examined a population with an echogenic focus for chromosomal anomalies.

RESULTS

There were 479 cases of echogenic focus; 90.4% were isolated, whereas 9.6% had associated findings. Eleven patients had fetuses with trisomy 21 (9 per 10,000). Eight of those did not have an echogenic focus, whereas 3 had a heart echogenic focus. Only 1 fetus with trisomy 21 had an isolated echogenic focus. The positive likelihood ratio for total cases of a heart echogenic focus and trisomy 21 was 7.25, whereas for an isolated echogenic focus, the positive likelihood ratio was 2.66.

CONCLUSIONS

The results of the statistical analysis showed that the risk of aneuploidy is increased in fetuses with an echogenic intracardiac focus; however, the finding should prompt a detailed structural survey and correlation with a priori risk. Amniocentesis need not be offered to patients who are otherwise at low risk and have an isolated echogenic intracardiac focus.

Childhood cardiac function after prenatal diagnosis of intracardiac echogenic foci

OBJECTIVE

To determine whether prenatally diagnosed intracardiac echogenic foci are associated with childhood cardiac dysfunction and persistence.

METHODS

Children in whom intracardiac echogenic foci were shown on prenatal sonography at 1 perinatal center underwent echocardiography at ages 2 to 7 years. A single pediatric cardiologist, blinded to the prenatal sonographic intracardiac echogenic focus locations, assessed cardiac function by measuring the left ventricular shortening fraction and myocardial performance index. The presence of tricuspid and mitral valve regurgitation was also sought. The secondary outcome was intracardiac echogenic focus persistence.

RESULTS

Twenty-five children, 14 (56%) male and 11 (44%) female, were examined at a mean age +/- SD of 3.0 +/- 1.0 years. Prenatally, 18 children (72%) had left ventricular intracardiac echogenic foci, and 7 (28%) had right ventricular intracardiac echogenic foci. The left ventricular shortening fraction was normal in all children. The overall mean left ventricular myocardial performance index (reference value, 0.36 +/- 0.06), was normal for both children with left ventricular intracardiac echogenic foci (0.36 +/- 0.06) and those with right ventricular intracardiac echogenic foci (0.36 +/- 0.04). Two children with left ventricular intracardiac echogenic foci had an isolated left ventricular myocardial performance index of greater than 2.5 SD above the mean. Trace tricuspid valve regurgitation and mitral valve regurgitation were noted in 13 (52%) and 2 (8%) of the children, respectively, similar to the general population. Left ventricular intracardiac echogenic foci persisted in 16 children (89%), whereas right ventricular intracardiac echogenic foci persisted in 2 (29%) (P = .007).

CONCLUSIONS

Prenatally diagnosed intracardiac echogenic foci are often persistent but not associated with childhood myocardial dysfunction.