Ethnic variation in the prevalence of echogenic intracardiac foci and the association with Down syndrome

Society for Maternal-Fetal Medicine Consult Series #57: Evaluation and management of isolated soft ultrasound markers for aneuploidy in the second trimester: (Replaces Consults #10, Single umbilical artery, October 2010; #16, Isolated echogenic bowel diagnosed on second-trimester ultrasound, August 2011; #17, Evaluation and management of isolated renal pelviectasis on second-trimester ultrasound, December 2011; #25, Isolated fetal choroid plexus cysts, April 2013; #27, Isolated echogenic intracardiac focus, August 2013)

Soft markers were originally introduced to prenatal ultrasonography to improve the detection of trisomy 21 over that achievable with age-based and serum screening strategies. As prenatal genetic screening strategies have greatly evolved in the last 2 decades, the relative importance of soft markers has shifted. The purpose of this document is to discuss the recommended evaluation and management of isolated soft markers in the context of current maternal serum screening and cell-free DNA screening options. In this document, "isolated" is used to describe a soft marker that has been identified in the absence of any fetal structural anomaly, growth restriction, or additional soft marker following a detailed obstetrical ultrasound examination. In this document, "serum screening methods" refers to all maternal screening strategies, including first-trimester screen, integrated screen, sequential screen, contingent screen, or quad screen. The Society for Maternal-Fetal Medicine recommends the following approach to the evaluation and management of isolated soft markers: (1) we do not recommend diagnostic testing for aneuploidy solely for the evaluation of an isolated soft marker following a negative serum or cell-free DNA screening result (GRADE 1B); (2) for pregnant people with no previous aneuploidy screening and isolated echogenic intracardiac focus, echogenic bowel, urinary tract dilation, or shortened humerus, femur, or both, we recommend counseling to estimate the probability of trisomy 21 and a discussion of options for noninvasive aneuploidy screening with cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive (GRADE 1B); (3) for pregnant people with no previous aneuploidy screening and isolated thickened nuchal fold or isolated absent or hypoplastic nasal bone, we recommend counseling to estimate the probability of trisomy 21 and a discussion of options for noninvasive aneuploidy screening through cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive or diagnostic testing via amniocentesis, depending on clinical circumstances and patient preference (GRADE 1B); (4) for pregnant people with no previous aneuploidy screening and isolated choroid plexus cysts, we recommend counseling to estimate the probability of trisomy 18 and a discussion of options for noninvasive aneuploidy screening with cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive (GRADE 1C); (5) for pregnant people with negative serum or cell-free DNA screening results and an isolated echogenic intracardiac focus, we recommend no further evaluation as this finding is a normal variant of no clinical importance with no indication for fetal echocardiography, follow-up ultrasound imaging, or postnatal evaluation (GRADE 1B); (6) for pregnant people with negative serum or cell-free DNA screening results and isolated fetal echogenic bowel, urinary tract dilation, or shortened humerus, femur, or both, we recommend no further aneuploidy evaluation (GRADE 1B); (7) for pregnant people with negative serum screening results and isolated thickened nuchal fold or absent or hypoplastic nasal bone, we recommend counseling to estimate the probability of trisomy 21 and discussion of options for no further aneuploidy evaluation, noninvasive aneuploidy screening through cell-free DNA, or diagnostic testing via amniocentesis, depending on clinical circumstances and patient preference (GRADE 1B); (8) for pregnant people with negative cell-free DNA screening results and isolated thickened nuchal fold or absent or hypoplastic nasal bone, we recommend no further aneuploidy evaluation (GRADE 1B); (9) for pregnant people with negative serum or cell-free DNA screening results and isolated choroid plexus cysts, we recommend no further aneuploidy evaluation, as this finding is a normal variant of no clinical importance with no indication for follow-up ultrasound imaging or postnatal evaluation (GRADE 1C); (10) for fetuses with isolated echogenic bowel, we recommend an evaluation for cystic fibrosis and fetal cytomegalovirus infection and a third-trimester ultrasound examination for reassessment and evaluation of growth (GRADE 1C); (11) for fetuses with an isolated single umbilical artery, we recommend no additional evaluation for aneuploidy, regardless of whether results of previous aneuploidy screening were low risk or testing was declined. We recommend a third-trimester ultrasound examination to evaluate growth and consideration of weekly antenatal fetal surveillance beginning at 36 0/7 weeks of gestation (GRADE 1C); (12) for fetuses with isolated urinary tract dilation A1, we recommend an ultrasound examination at ≥32 weeks of gestation to determine if postnatal pediatric urology or nephrology follow-up is needed. For fetuses with urinary tract dilation A2-3, we recommend an individualized follow-up ultrasound assessment with planned postnatal follow-up (GRADE 1C); (13) for fetuses with isolated shortened humerus, femur, or both, we recommend a third-trimester ultrasound examination for reassessment and evaluation of growth (GRADE 1C).

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.

Meta-analysis of validity of echogenic intracardiac foci for calculating the risk of Down syndrome in the second trimester of pregnancy

Echogenic intracardiac foci are a second trimester marker associated with aneuploidy in high-risk populations. The objective of this study is to assess the validity of echogenic intracardiac foci for Down syndrome detection in the second trimester ultrasound scan. A systematic search in major bibliographic databases was carried out (MEDLINE, EMBASE, CINAHL). Twenty-five studies about echogenic intracardiac foci were selected for statistical synthesis in this systematic review. Those 25 considered to be relevant were then subjected to critical reading, following the Critical Appraisal Skills Programme criteria, by at least three independent observers. Then, the published articles were subjected to a meta-analysis. A global sensitivity of 21.8% and a 4.1% false positive rate were obtained. The positive likelihood ratio was 5.08 (95% confidence interval, 4.04-6.41). The subgroups analysis did not reveal statistically significant differences. In conclusion, echogenic intracardiac foci as an isolated marker could be a tool to identify-rather than exclude-the high-risk group of Down syndrome, although it should be noted that it shows low sensitivity.

Fetal proximal humeral epiphysis as an indicator of term gestation in different ethnic groups. J Matern Fetal Neonatal Med 2016;30:2505-2509. [PMID: 27819180 DOI: 10.1080/14767058.2016.1254184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

OBJECTIVES

Accurate pregnancy dating is critical for appropriate clinical management. Our aim was to determine the time of appearance of proximal humeral epiphysis (PHE), consistency of its appearance among ethnic groups and whether 3D imaging helps with its visualization.

METHODS

A cross-sectional study was done on 360 patients with 563 scans in different ethnic groups between August 2013 and July 2015. Inclusion criteria were singleton pregnancies (34-40+  weeks of gestation), well dated by <20 weeks sonogram.

RESULTS

PHE was not seen at 34 (n = 44) or 35 weeks (n = 36) and was present at gestational ages 36 (n = 3), 37 (n = 126), 38 (n = 96), 39 (n = 100) and 40 weeks (n = 28) in 2%, 12%, 51%, 75% and 100%, respectively. PHE was seen in 20 of 50 (60%) African-Americans, 22 of 61 (64%) south Asians, 41 of 72 (57%) Caucasians, 45 of 86 (48%) Hispanics and 41 of 80 (49%) Asians.

CONCLUSION

Appearance of PHE did increase with gestational age, prior to 40 weeks, it was not uniformly present and was seen as early as 36 weeks independent of ethnic group.

Echogenic intracardiac focus on second trimester ultrasound: prevalence and significance in a Middle Eastern population

OBJECTIVE

The association between echogenic intracardiac focus (EIF) and trisomy 21 is well established, with a recognized ethnic variation. Our study aimed to determine the prevalence of EIF in a Middle Eastern population and to examine its association with trisomy 21 and other adverse pregnancy outcomes.

METHODS

Retrospective case-control study of second-trimester obstetric sonograms (16-28 weeks) performed at a tertiary care center over a 5-year period. Cases with EIF were retrieved, and a matched control group with no EIF was identified. The incidence of trisomy 21 and other adverse pregnancy outcomes was compared.

RESULTS

A total of 9270 obstetric sonograms were examined, with an EIF prevalence of 2.5% (95% CI: 2.2-2.8%). Of patients with available outcome data, EIF was not associated with trisomy 21 (0/163 versus 1/163; p value = 1.00). Additionally, EIF was not associated with trisomy 18, trisomy 13, small for gestational age, preterm birth, fetal demise, cesarean delivery, operative vaginal delivery, or admission to the neonatal intensive care unit.

CONCLUSION

In a contemporary Middle Eastern population, EIF is a rare occurrence. As an isolated finding, it is not associated with aneuploidy or other adverse pregnancy outcomes. EIF appears to be incidental with no impact on clinical practice.

Retrospective analysis of live birth prevalence of children with Down syndrome in Denizli, Turkey

Down syndrome (DS) is the most frequent chromosome abnormality among live births. Its prevalence increases with maternal age, and can be diagnosed by antenatal screening. We examined prevalence variations of DS in Denizli, Turkey, through a retrospective study. Sixteen years of survey data were retrieved from the two main state hospital registries from records between 1994 and 2010. We identified 113 DS live births in Denizli for 16 years. The prevalence of DS was 9.07 per 10,000 live births before the year 2000 and 9.90 after 2000. The prevalence did not change significantly. The population in Turkey is still young; the fertility rate is high in women under 35 years old and prenatal screening programs are extensively applied; for these reasons, the prevalence of DS has remained stable during these 16 years.

The association of maternal BMI with fetal echogenic intracardiac foci and echogenic bowel

OBJECTIVES

To evaluate the impact of maternal body mass index (BMI) as well as maternal ethnicity on the detection of either echogenic intra-cardiac focus (EIF) or echogenic bowel (EB).

METHODS

This prospective study identified 74 uncomplicated singleton fetuses in which EIF and/or EB were detected between 18 and 21 weeks of gestation (i.e. study group). Seventy four consecutively scanned fetuses without EIF or EB, at the same gestational age, were selected as controls. The differences in maternal BMI and maternal ethnicity were compared between the two groups using the chi(2) test, Fisher's exact test, and the Student t-test. A multivariable logistic regression model was constructed to control for confounders. Odds ratios (OR) and their 95% confidence interval (CI) were computed.

RESULTS

The mean maternal BMI was significantly lower in the study group as compared to controls (22.9 +/- 3.1 vs. 28.0 +/- 7.5 kg/m(2), respectively; p < 0.0001). Patients with fetal EIF and/or EB were significantly more likely to be Asians (20.3% vs. 5.4%, OR = 4.5; 95% CI 1.3-16.9). Using a multivariable analysis, controlling for ethnicity, the association between maternal BMI and fetal EIF or EB remained significant (OR = 0.83; 95% CI 0.76-0.91). However, based on this model Asian ethnicity was not an independent risk factor for the detection of EIF and/or EB (OR = 2.6; 95% CI 0.8-8.9).

CONCLUSIONS

Our data suggests an inverse relationship between the maternal BMI and the detection of fetal EIF and/or EB. Moreover, it appears that low maternal BMI, and not Asian ethnicity, is an independent risk factor for the detection of these echogenic fetal findings.

Aneuploidy: from a physiological mechanism of variance to Down syndrome

Quantitative differences in gene expression emerge as a significant source of variation in natural populations, representing an important substrate for evolution and accounting for a considerable fraction of phenotypic diversity. However, perturbation of gene expression is also the main factor in determining the molecular pathogenesis of numerous aneuploid disorders. In this review, we focus on Down syndrome (DS) as the prototype of "genomic disorder" induced by copy number change. The understanding of the pathogenicity of the extra genomic material in trisomy 21 has accelerated in the last years due to the recent advances in genome sequencing, comparative genome analysis, functional genome exploration, and the use of model organisms. We present recent data on the role of genome-altering processes in the generation of diversity in DS neural phenotypes focusing on the impact of trisomy on brain structure and mental retardation and on biological pathways and cell types in target brain regions (including prefrontal cortex, hippocampus, cerebellum, and basal ganglia). We also review the potential that genetically engineered mouse models of DS bring into the understanding of the molecular biology of human learning disorders.

Time to reconsider our approach to echogenic intracardiac focus and choroid plexus cysts

Ultrasound soft markers are commonly reported at mid-trimester ultrasounds. Soft markers frequently arouse anxiety in the patient, her family, and the referring clinician. Recent publications have raised concerns that this anxiety may be unfounded. The significance of an echogenic intracardiac focus or choroid plexus cyst in particular is no longer certain. It may be time to discard these two markers; especially if they are reported in isolation and in a patient who is otherwise at low risk for aneuploidy.

Uptake of invasive prenatal diagnostic tests in women after detection of soft markers for chromosomal abnormality on ultrasonographic evaluation

OBJECTIVE

Use of soft ultrasonographic markers during routine prenatal ultrasonography (USG) may be used for the screening of aneuploidy in the low-risk population. The aim of this study was to evaluate the acceptance of an invasive test for prenatal diagnosis and to assess the role of various factors in the decision-making regarding an invasive test when confronted with risk for aneuploidy after a soft marker is detected on routine antenatal ultrasonogram.

STUDY DESIGN

Women were referred for USG in our department by primary obstetricians for indications such as a previous child with a congenital malformation, genetic disorder, stillbirth or in women with recurrent spontaneous abortions. Some of the women were referred after prenatal detection of a soft marker on USG. They were screened for soft markers associated with chromosomal abnormality. They were counseled regarding the age-specific risk and the risk of aneuploidy after detection of a marker in comparison to the general population's risk of Down's syndrome. They were also counseled regarding the risk of a procedure-related abortion (0.5%) following an invasive procedure before their decision regarding the use of amniocentesis was made.

RESULT

Twenty women out of 50 (40%) opted for amniocentesis. Except in one case of trisomy 21 in a fetus with short femur and humerus, all others had normal karyotype. The uptake of the test was comparable between primigravida (33%), women with poor obstetric history (46%) and women with at least one normal live child (45%). There was no statistical difference in the uptake of invasive test based on gestational age as well. Uptake of amniocentesis was higher (78%) in cases with nuchal thickening as compared to other markers (35%).

CONCLUSION

Ultrasonographic detection of soft markers is associated with a high frequency of uptake for invasive prenatal testing. Increased nuchal thickening is associated with a higher acceptance of amniocentesis. Maternal age, gestational age or previous obstetric history were not associated with the decision to undergo amniocentesis.

Management options for echogenic intracardiac focus and choroid plexus cysts: A review including Australian Association of Obstetrical and Gynaecological Ultrasonologists consensus statement

Echogenic intracardiac focus and choroid plexus cysts are common findings at the midtrimester ultrasound. These findings have been linked with an increased risk of Down syndrome and trisomy 18. Most fetuses with these findings will, however, not have chromosomal abnormalities, especially when these findings are isolated. Patients experience considerable anxiety when informed of these findings and require extensive counselling in order to minimize anxiety not only about aneuploidy but also about the structure and development of the heart and brain. Although early studies showed an association with aneuploidies, several recent studies have cast doubt on this association. Many of the early studies were carried out in high-risk populations or in populations that had not had the benefit of other screening tests. Many Australian and New Zealand patients will access screening tests designed to detect these aneuploidies before presenting for a midtrimester ultrasound. Patients who have been screened by nuchal translucency, maternal serum screening or some combination of the two will already have had most cases of Down syndrome and trisomy 18 detected, and any soft marker found will almost certainly be a false positive. It is time to rethink the management of these markers. Recent evidence indicates that if these markers are found in isolation in an otherwise low-risk pregnancy, then there is minimal or no increase in the risk of Down syndrome or trisomy 18: these markers should be considered normal variants. The Australian Association of Obstetrical and Gynaecological Ultrasonologists consensus statement on these markers is included.