Detection of congenital heart defects throughout pregnancy; impact of first trimester ultrasound screening for cardiac abnormalities

Clinical implementation of first trimester screening for congenital heart defects

OBJECTIVE

To examine the feasibility and performance of implementing a standardized fetal cardiac scan at the time of a routine first-trimester ultrasound scan.

METHOD

A retrospective, single-center study in an unselected population between March 2021 and July 2022. A standardized cardiac scan protocol consisting of a four-chamber and 3-vessel trachea view with color Doppler was implemented as part of the routine first-trimester scan. Sonographers were asked to categorize the fetal heart anatomy. Data were stratified into two groups based on the possibility of evaluating the fetal heart. The influence of maternal and fetal characteristics and the detection of major congenital heart disease were investigated.

RESULTS

A total of 5083 fetuses were included. The fetal heart evaluation was completed in 84.9%. The proportion of successful scans increased throughout the study period from 76% in the first month to 92% in the last month. High maternal body mass index and early gestational age at scan significantly decreased the feasibility. The first-trimester detection of major congenital heart defects was 7/16, of which four cases were identified by the cardiac scan protocol with no false-positive cases.

CONCLUSION

First-trimester evaluation of the fetal heart by a standardized scan protocol is feasible to implement in daily practice. It can contribute to the earlier detection of congenital heart defects at a very low false positive rate.

Diagnostic accuracy of ultrasound screening for fetal structural abnormalities during the first and second trimester of pregnancy in low-risk and unselected populations

BACKGROUND

Prenatal ultrasound is widely used to screen for structural anomalies before birth. While this is traditionally done in the second trimester, there is an increasing use of first-trimester ultrasound for early detection of lethal and certain severe structural anomalies.

OBJECTIVES

To evaluate the diagnostic accuracy of ultrasound in detecting fetal structural anomalies before 14 and 24 weeks' gestation in low-risk and unselected pregnant women and to compare the current two main prenatal screening approaches: a single second-trimester scan (single-stage screening) and a first- and second-trimester scan combined (two-stage screening) in terms of anomaly detection before 24 weeks' gestation.

SEARCH METHODS

We searched MEDLINE, EMBASE, Science Citation Index Expanded (Web of Science), Social Sciences Citation Index (Web of Science), Arts & Humanities Citation Index and Emerging Sources Citation Index (Web of Science) from 1 January 1997 to 22 July 2022. We limited our search to studies published after 1997 and excluded animal studies, reviews and case reports. No further restrictions were applied. We also screened reference lists and citing articles of each of the included studies.

SELECTION CRITERIA

Studies were eligible if they included low-risk or unselected pregnant women undergoing a first- and/or second-trimester fetal anomaly scan, conducted at 11 to 14 or 18 to 24 weeks' gestation, respectively. The reference standard was detection of anomalies at birth or postmortem.

DATA COLLECTION AND ANALYSIS

Two review authors independently undertook study selection, quality assessment (QUADAS-2), data extraction and evaluation of the certainty of evidence (GRADE approach). We used univariate random-effects logistic regression models for the meta-analysis of sensitivity and specificity.

MAIN RESULTS

Eighty-seven studies covering 7,057,859 fetuses (including 25,202 with structural anomalies) were included. No study was deemed low risk across all QUADAS-2 domains. Main methodological concerns included risk of bias in the reference standard domain and risk of partial verification. Applicability concerns were common in studies evaluating first-trimester scans and two-stage screening in terms of patient selection due to frequent recruitment from single tertiary centres without exclusion of referrals. We reported ultrasound accuracy for fetal structural anomalies overall, by severity, affected organ system and for 46 specific anomalies. Detection rates varied widely across categories, with the highest estimates of sensitivity for thoracic and abdominal wall anomalies and the lowest for gastrointestinal anomalies across all tests. The summary sensitivity of a first-trimester scan was 37.5% for detection of structural anomalies overall (95% confidence interval (CI) 31.1 to 44.3; low-certainty evidence) and 91.3% for lethal anomalies (95% CI 83.9 to 95.5; moderate-certainty evidence), with an overall specificity of 99.9% (95% CI 99.9 to 100; low-certainty evidence). Two-stage screening had a combined sensitivity of 83.8% (95% CI 74.7 to 90.1; low-certainty evidence), while single-stage screening had a sensitivity of 50.5% (95% CI 38.5 to 62.4; very low-certainty evidence). The specificity of two-stage screening was 99.9% (95% CI 99.7 to 100; low-certainty evidence) and for single-stage screening, it was 99.8% (95% CI 99.2 to 100; moderate-certainty evidence). Indirect comparisons suggested superiority of two-stage screening across all analyses regarding sensitivity, with no significant difference in specificity. However, the certainty of the evidence is very low due to the absence of direct comparisons.

AUTHORS' CONCLUSIONS

A first-trimester scan has the potential to detect lethal and certain severe anomalies with high accuracy before 14 weeks' gestation, despite its limited overall sensitivity. Conversely, two-stage screening shows high accuracy in detecting most fetal structural anomalies before 24 weeks' gestation with high sensitivity and specificity. In a hypothetical cohort of 100,000 fetuses, the first-trimester scan is expected to correctly identify 113 out of 124 fetuses with lethal anomalies (91.3%) and 665 out of 1776 fetuses with any anomaly (37.5%). However, 79 false-positive diagnoses are anticipated among 98,224 fetuses (0.08%). Two-stage screening is expected to correctly identify 1448 out of 1776 cases of structural anomalies overall (83.8%), with 118 false positives (0.1%). In contrast, single-stage screening is expected to correctly identify 896 out of 1776 cases before 24 weeks' gestation (50.5%), with 205 false-positive diagnoses (0.2%). This represents a difference of 592 fewer correct identifications and 88 more false positives compared to two-stage screening. However, it is crucial to acknowledge the uncertainty surrounding the additional benefits of two-stage versus single-stage screening, as there are no studies directly comparing them. Moreover, the evidence supporting the accuracy of first-trimester ultrasound and two-stage screening approaches primarily originates from studies conducted in single tertiary care facilities, which restricts the generalisability of the results of this meta-analysis to the broader population.

Nuchal Translucency and Congenital Heart Defects

Nuchal translucency comprises a temporary accumulation of fluid in the subcutaneous tissue on the back of a fetus's neck, which accompanies the crown-rump length and is observed through an ultrasound performed between 11 and 13 weeks + 6 days gestation. Nuchal translucency is considered to be above normal when values are higher than the 95th/99th percentile or equal to or higher than 2.5/3.5 mm. The first connection between increased nuchal translucency and the presence of congenital heart defects is described in the study of Hyett et al., who observed that they are directly proportional. Since that time, several studies have been conducted to understand if nuchal translucency measurements can be used for congenital heart defect screening in euploid fetuses. However, there is great variability in the estimated nuchal translucency cutoff values for congenital heart defect detection. The purpose of this review was to understand how increased nuchal translucency values and congenital heart defects are related and to identify which of these defects are more frequently associated with an increase in these values.

Four-section approach of fetal congenital heart disease at 11-13+6 weeks

Objective

The objective of the study is to explore the value of the four-section approach in detecting fetal heart defects in the first trimester (11-13+6 weeks), analyze the reasons for the inconsistency between the results of ultrasound examination in the first trimester and subsequent verification, and describe the most common abnormal flow patterns of four sections.

Materials and methods

Between June 2019 and June 2021, a prenatal four-section approach (upper abdominal transverse section, four-chamber section, three vessel-trachea section, and bilateral subclavian artery section) with verification results in early pregnancy was analyzed.

Results

In total, 9,533 fetuses were included. Finally, 176 fetuses with congenital heart disease (CHD), containing 34 types, were identified. The total detection rate of cardiac abnormalities was 1.85%. 102 cases were accurately diagnosed by ultrasonography during early pregnancy. A total of 74 fetuses who had inconsistent results between fetal cardiac ultrasound and verification in early pregnancy were reported, of which the cases of 22 fetuses were inconsistent due to disease evolution and progression and the cases of 52 fetuses were inconsistent due to missed diagnosis and misdiagnosis. The sensitivity, specificity, positive predictive value, and negative predictive value of the four-section approach were 67.05%, 99.96%, 96.58%, and 99.33%, respectively. In this study, a total of 30 abnormal ultrasonic imaging patterns in four sections were summarized.

Conclusion

We confirmed that the four-section approach in early pregnancy has a good diagnostic efficacy for fetal CHD. Intrauterine evolution of the fetal heart, missed diagnosis, and misdiagnosis are the reasons for the inconsistency between the results of early pregnancy ultrasound and subsequent verification. This study also presents the abnormal imaging patterns of four scan sections of CHD in early pregnancy, which are instructive for the rapid identification and diagnosis of CHD in the first trimester.

Prevalence and risk factors for congenital heart defects among children in the Multi-Ethnic Yunnan Region of China

BACKGROUND

To determine the congenital heart defect (CHD) prevalence and identify the associated risk factors in children within the multi-ethnic Yunnan Region of China.

METHODS

This is a prospective matched case-control screening study. Screening for CHD in children residing within 28 county districts of Yunnan Province during the period of January 2001 to December 2016 was conducted. A total of 2,421 and CHD cohort and 24,210 control cohort were derived from a total population of 400,855 children (under 18 years of age).

RESULTS

A total of 2,421 children were diagnosed with CHD, yielding a CHD prevalence of 6.04 cases per 1,000 children. The prevalence of CHD by sex was 6.54 per 1,000 females versus 5.59 per 1,000 males. The ethnic groups displaying the highest CHD prevalence were the Lisu (15.51 per 1,000), Achang (13.18 per 1,000), Jingpo (12.32 per 1,000), Naxi (9.68 per 1,000), and Tibetan (8.57 per 1,000), respectively. The most common CHD was atrial septal defect, amounting to 1.94 instances per 1,000 children. We identified a number of child-associated parameters that significantly correlated with greater CHD risk, such as lower mass at birth, shorter duration of gestation, and younger age at the time of screening. We also identified a number of maternal and familial risk factors.

CONCLUSIONS

This ultrasonic color Doppler imaging study revealed a relatively commonplace prevalence of CHD. Moreover, the prevalence of CHD in Yunnan Region significantly varied with sex and ethnic status. Certain child-associated, maternal, and familial risk factors may contribute to CHD risk.

First-trimester ultrasound detection of fetal heart anomalies: systematic review and meta-analysis

OBJECTIVES

To determine the diagnostic accuracy of ultrasound at 11-14 weeks' gestation in the detection of fetal cardiac abnormalities and to evaluate factors that impact the detection rate.

METHODS

This was a systematic review of studies evaluating the diagnostic accuracy of ultrasound in the detection of fetal cardiac anomalies at 11-14 weeks' gestation, performed by two independent reviewers. An electronic search of four databases (MEDLINE, EMBASE, Web of Science Core Collection and The Cochrane Library) was conducted for studies published between January 1998 and July 2020. Prospective and retrospective studies evaluating pregnancies at any prior level of risk and in any healthcare setting were eligible for inclusion. The reference standard used was the detection of a cardiac abnormality on postnatal or postmortem examination. Data were extracted from the included studies to populate 2 × 2 tables. Meta-analysis was performed using a random-effects model in order to determine the performance of first-trimester ultrasound in the detection of major cardiac abnormalities overall and of individual types of cardiac abnormality. Data were analyzed separately for high-risk and non-high-risk populations. Preplanned secondary analyses were conducted in order to assess factors that may impact screening performance, including the imaging protocol used for cardiac assessment (including the use of color-flow Doppler), ultrasound modality, year of publication and the index of sonographer suspicion at the time of the scan. Risk of bias and quality assessment were undertaken for all included studies using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool.

RESULTS

The electronic search yielded 4108 citations. Following review of titles and abstracts, 223 publications underwent full-text review, of which 63 studies, reporting on 328 262 fetuses, were selected for inclusion in the meta-analysis. In the non-high-risk population (45 studies, 306 872 fetuses), 1445 major cardiac anomalies were identified (prevalence, 0.41% (95% CI, 0.39-0.43%)). Of these, 767 were detected on first-trimester ultrasound examination of the heart and 678 were not detected. First-trimester ultrasound had a pooled sensitivity of 55.80% (95% CI, 45.87-65.50%), specificity of 99.98% (95% CI, 99.97-99.99%) and positive predictive value of 94.85% (95% CI, 91.63-97.32%) in the non-high-risk population. The cases diagnosed in the first trimester represented 63.67% (95% CI, 54.35-72.49%) of all antenatally diagnosed major cardiac abnormalities in the non-high-risk population. In the high-risk population (18 studies, 21 390 fetuses), 480 major cardiac anomalies were identified (prevalence, 1.36% (95% CI, 1.20-1.52%)). Of these, 338 were detected on first-trimester ultrasound examination and 142 were not detected. First-trimester ultrasound had a pooled sensitivity of 67.74% (95% CI, 55.25-79.06%), specificity of 99.75% (95% CI, 99.47-99.92%) and positive predictive value of 94.22% (95% CI, 90.22-97.22%) in the high-risk population. The cases diagnosed in the first trimester represented 79.86% (95% CI, 69.89-88.25%) of all antenatally diagnosed major cardiac abnormalities in the high-risk population. The imaging protocol used for examination was found to have an important impact on screening performance in both populations (P < 0.0001), with a significantly higher detection rate observed in studies using at least one outflow-tract view or color-flow Doppler imaging (both P < 0.0001). Different types of cardiac anomaly were not equally amenable to detection on first-trimester ultrasound.

CONCLUSIONS

First-trimester ultrasound examination of the fetal heart allows identification of over half of fetuses affected by major cardiac pathology. Future first-trimester screening programs should follow structured anatomical assessment protocols and consider the introduction of outflow-tract views and color-flow Doppler imaging, as this would improve detection rates of fetal cardiac pathology. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Effectiveness of fetal ultrasound diagnostics in cardiac malformations and association with polyhydramnios and oligohydramnios

BACKGROUND

Examine the effectiveness of prenatal ultrasound diagnostics in the detection of cardiovascular malformations, and their association with polyhydramnios and oligohydramnios.

METHODS

We examined the fetal ultrasonography and postnatal clinical/fetopathological data of 372 newborns/fetuses over a 7-year period in a tertiary centre. Fetal echocardiography was performed in cases of suspected US findings between 18-32 weeks. During the ultrasound the amniotic fluid amount was measured and the amniotic fluid index (AFI) or largest amniotic fluid pocket was determined.

RESULTS

Prenatal ultrasonographic results and postnatal/fetopathological diagnosis were fully congruent in 236/372 cases (63.4%), and in 66/372 cases of cardiovascular anomalies (17.7%) the discovery was partial, while in 70/372 cases no fetal cardiovascular anomalies were diagnosed during pregnancy (18.8%) (false negative). Cardiovascular malformations were isolated in 255 cases, in 172 of which (67.5%) the results of prenatal ultrasonography and postnatal diagnostics were fully congruent. In 43 cases (16.9%) the prenatal discovery was partial, and in 40 cases (15.7%) there was no prenatal recognition of the malformation. Cardiovascular abnormalities were found as a part of multiple malformations in 76 cases. In 41 fetuses the cardiovascular malformation was associated with chromosomal abnormalities. Cardiovascular malformations were significantly associated with polyhydramnios. Although in some of the cardiovascular malformations the association rate with polyhydramnios was high (AVSD, double outlet right ventricle, tetralogy of Fallot), we found a moderate association rate (19.7%). The association with oligohydramnios was 8.57%.

CONCLUSIONS

Echocardiography plays an important role in the prenatal diagnostics. In cases of polyhydramnios and oligohydramnios, fetal echocardiography should be performed.

Cardiac axis evaluation as a screening method for detecting cardiac abnormalities in the first trimester of pregnancy

Congenital cardiac abnormalities refer to especially anatomic malformations of the heart that normally occur during fetal heart development, before eight weeks after conception. Aim: The aim is to investigate the association between cardiac axis and congenital heart abnormalities for a potential underline clinical application of cardiac axis evaluation during detection by abnormalities at the time of first trimester ultrasound. It is known that aneuploids can be associated in almost half of cases with cardiac abnormalities, so the angle of the cardiac axis could be a potential indirect marker for the detection of aneuploids in the first trimester of pregnancy. Being easy to obtain, from the cross-section at the chest level with the visualization of the four chambers, does not require additional sections to those provided in the current guides, we aim to prove its usefulness in diagnosing aneuploids and congenital cardiac abnormalities along with the translucent nuchal flow, at the level of the venous duct and the presence of tricuspid regurgitation. Conclusions: Cardiac axis has a higher value for the detection of congenital cardiac abnormalities with respect to the nuchal translucency, tricuspid regurgitation and inverted A wave at the level of the venous duct.

Screening performance of congenital heart defects in first trimester using simple cardiac scan, nuchal translucency, abnormal ductus venosus blood flow and tricuspid regurgitation

OBJECTIVE

The objective of this study was to analyze if the addition of simple cardiac scan in cases with increased nuchal translucency (NT) and/or abnormal ductus venosus (DV) blood flow, and/or tricuspid regurgitation (TCR) can improve detection of congenital heart defects (CHD) in chromosomally normal fetuses without non-cardiac defects at 11-13 + 6 gestational weeks in a population of singleton pregnancies.

METHODS

During the 10 years period, all singleton pregnancies at 11-13 + 6 weeks were routinely scanned for NT, DV blood flow and TCR assessment and, if a single of these parameters was abnormal, simple cardiac scan with 2D gray scale and color and/or directional power Doppler in 4-chamber (4-CV) and 3 vessel and trachea views (3VTV) was performed.

RESULTS

The sensitivity and specificity of NT ≥ 95th + DV R/A a-wave + TCR in detecting CHD were 77% and 97%, respectively, and of simple cardiac scan, 67% and 98%, respectively. Area under the curve of receiver operating characteristic curve of NT ≥ 95th + DV R/A a-wave + TCR was 0.838, and of NT ≥ 95th + DV R/A a-wave + TCR + simple cardiac scan was 0.915.

CONCLUSIONS

In chromosomally normal fetuses without non-cardiac anomalies, addition of simple cardiac scan to the combined first trimester screening parameters improves detection of major CHD during first trimester.

Diagnostic value of echocardiography in fetal cardiac malformation and clinical classification

Diagnostic value of echocardiography in fetal cardiac malformation and clinical classification was investigated. In total, 206 high-risk parturients, who received a screening of prenatal fetal cardiac malformation in Jinan Maternity and Child Care Hospital from January 2015 to June 2017, were retrospectively analyzed, among those parturients, the results of labor induction or newborns of 141 parturients were diagnosed as cardiac malformation, the fetuses of 65 parturients were diagnosed as non-cardiac malformation, the detection of fetal cardiac malformation of all the parturients was carried out by two-dimensional ultrasound and four-dimensional ultrasound during gestation period, presence or absence of congenital cardiac malformation of the fetuses and clinical classification were estimated. The sensitivity of two-dimensional ultrasound diagnosis combined with four-dimensional ultrasound diagnosis was significantly higher than that of two-dimensional ultrasound diagnosis and four-dimensional ultrasound diagnosis (P<0.05). In addition, the sensitivity of four-dimensional ultrasound diagnosis was significantly higher than that of two-dimensional ultrasound diagnosis (P<0.05). The specificity and positive predictive value of four-dimensional ultrasound diagnosis were significantly higher than those of two-dimensional ultrasound diagnosis and two-dimensional ultrasound diagnosis combined with four-dimensional ultrasound diagnosis (P<0.05). The diagnostic coincidence rates of four-dimensional ultrasound diagnosis and two-dimensional ultrasound diagnosis combined with four-dimensional ultrasound diagnosis were significantly higher than that of two-dimensional ultrasound diagnosis (P<0.05). The negative predictive values of the combined ultrasound diagnosis and four-dimensional ultrasound diagnosis were significantly higher than that of two-dimensional ultrasound diagnosis (P<0.05). The diagnostic efficiency of two-dimensional ultrasound combined with four-dimensional ultrasound was good in the diagnosis of fetal cardiac malformation in prenatal period of pregnant women, it could improve detection rate of fetal cardiac malformation and is worthy of being generalized in clinic.

Contribution of the Fetal Cardiac Axis and V-Sign Angle in First-Trimester Screening for Major Cardiac Defects

OBJECTIVE

To estimate the potential value of fetal assessment for the cardiac axis (CAx) and V-sign angle (VSA) in the first trimester in the prediction of fetal major cardiac defects.

METHODS

A cohort study was conducted from December 2015 to June 2016. Patients with singleton pregnancies and crown-rump length from 45 to 84 mm were recruited to undergo nuchal translucency sonography. The CAx on the 4-chamber view and the VSA on the 3-vessel and trachea view with Doppler mapping were measured. The estimated performance of different combinations of increased fetal nuchal translucency, CAx, and VSA in screening for major cardiac defects was examined.

RESULTS

The study population of fetuses included 30 fetuses with major cardiac defects and 1538 normal fetuses. The CAx and VSA were 30° to 60° and 30° to 40°, respectively, according to the 2.5th and 97.5th percentiles in normal fetuses. When cases of isolated septal wall defects and an isolated right aortic arch were excluded, nuchal translucency above the 95th percentile, an abnormal CAx, and an abnormal VSA were observed in 63.3% (19 of 30), 63.3% (19 of 30), and 66.7% (20 of 30) of fetuses with major cardiac defects, respectively, and in 4.6% (71 of 1538), 2.0% (30 of 1538), and 5.6% (86 of 1538) of those without cardiac defects. Either an abnormal CAx or VSA was found in 93.3% (28 of 30) of the fetuses with cardiac defects and in 7.3% (113 of 1538) of those without cardiac defects.

CONCLUSION

Assessment of the CAx and VSA is helpful in defining a population at risk for major cardiac defects in the first trimester.

Trends in gestational age at time of surgical abortion for fetal aneuploidy and structural abnormalities

BACKGROUND

Screening for fetal aneuploidy has evolved over the past 2 decades. Whether these advances impact gestational age at abortion has received little study.

OBJECTIVE

We sought to describe trends in the gestational age at the time of abortion by fetal diagnosis over an 11-year study period. We hypothesized that gestational age at time of abortion would decrease for fetal aneuploidy but remain unchanged for structural abnormalities.

STUDY DESIGN

We conducted a retrospective case series of all women undergoing surgical abortion for fetal aneuploidy or structural abnormalities up to 24 weeks' gestation from 2004 through 2014 in a hospital operating room setting at a single, urban medical center. We excluded labor induction abortions (<1% of abortions at our medical center) and suction aspirations performed in the office practice. We performed suction aspiration up to 14 weeks and dilation and evacuation after that gestational age. We describe the median gestational age at abortion by fetal indication and year.

RESULTS

For women undergoing abortion for fetal aneuploidy (n = 392), the median gestational age at time of abortion decreased from 19.0 weeks (interquartile range 18.0-21.0) in 2004 to 14.0 weeks (interquartile range 13.0-17.0) in 2014 (Kruskal-Wallis P < .0001). For women undergoing abortion for fetal structural abnormalities (n = 586), the median gestational age was ≥20 weeks for each year during the study interval (P = .1). As gestational age decreased in the fetal aneuploidy group, fewer women underwent dilation and evacuation and more became eligible for suction aspiration (<14 weeks). In 2004, >90% of women underwent dilation and evacuation for either indication. By 2014, 31% of women with fetal aneuploidy were eligible for suction aspiration compared to 11% of those with structural anomalies.

CONCLUSION

Gestational age at the time of abortion for fetal aneuploidy decreased substantially from 2004 through 2014; earlier abortion is safer for women. In contrast, women seeking abortion for fetal structural abnormalities did not experience a change in timing. Legislation restricting gestational age at the time of abortion could disproportionately affect women with fetal structural abnormalities.

miR-20a regulates proliferation, differentiation and apoptosis in P19 cell model of cardiac differentiation by targeting Smoothened

MicroRNA (miR)-20a, a member of the miR-17-92 cluster related to cardiac development, was obviously downregulated in myocardially differentiated P19 cells compared with normal P19 cells. Smoothened (SMO) is a member of the Hh pathway. Hh signaling induces cardiac differentiation in P19 cells, and SMO mediates the Hh pathway during embryonic development. Using bioinformatic prediction software Targetscan (http://www.targetscan.org/), PicTar (http://pictar.bio.nyu.edu), and miRBase (http://microrna.sanger.ac.uk/), miR-20a and the 3′-untranslated region (3′-UTR) of SMO mRNA were predicted to have complementary binding regions. Accordingly, we inferred that miR-20a might act as a regulator of SMO, and regulate proliferation, differentiation and apoptosis in P19 cells. We determined the expression of miR-20a, SMO and marker proteins of cardiomyocytes (cTnT, GATA4 and desmin) by quantitative real-time PCR (qRT-PCR) and western blot assays, and found that P19 cells had differentiated into cardiomyocytes successfully at differentiation day 10, and downregulation of miR-20a and upregulation of SMO existed in myocardially differentiated P19 cells. Cell proliferation, differentiation and apoptosis detection showed that miR-20a upregulation inhibited proliferation and differentiation and enhanced apoptosis in P19 cells. Moreover, we verified that miR-20a directly targeted SMO and knockdown of SMO and miR-20a overexpression had similar effects on P19 cell proliferation, differentiation and apoptosis, which verified the speculation that miR-20a inhibits proliferation and differentiation and enhances apoptosis in P19 cells by directly targeting SMO. Our results suggest that miR-20a may be a potential target against congenital heart diseases.

Summary: Our findings may bring a new viewpoint into the mechanisms of cardiac abnormalities and suggest that miR-20a may be a potential new therapeutic target for congenital heart diseases.

miR-30c regulates proliferation, apoptosis and differentiation via the Shh signaling pathway in P19 cells

MicroRNAs (miRNAs) are small, non-coding single-stranded RNAs that suppress protein expression by binding to the 3′ untranslated regions of their target genes. Many studies have shown that miRNAs have important roles in congenital heart diseases (CHDs) by regulating gene expression and signaling pathways. We previously found that miR-30c was highly expressed in the heart tissues of aborted embryos with ventricular septal defects. Therefore, this study aimed to explore the effects of miR-30c in CHDs. miR-30c was overexpressed or knocked down in P19 cells, a myocardial cell model that is widely used to study cardiogenesis. We found that miR-30c overexpression not only increased cell proliferation by promoting cell entry into S phase but also suppressed cell apoptosis. In addition, we found that miR-30c inhibited dimethyl sulfoxide-induced differentiation of P19 cells. miR-30c knockdown, in contrast, inhibited cell proliferation and increased apoptosis and differentiation. The Sonic hedgehog (Shh) signaling pathway is essential for normal embryonic development. Western blotting and luciferase assays revealed that Gli2, a transcriptional factor that has essential roles in the Shh signaling pathway, was a potential target gene of miR-30c. Ptch1, another important player in the Shh signaling pathway and a transcriptional target of Gli2, was downregulated by miR-30c overexpression and upregulated by miR-30c knockdown. Collectively, our study revealed that miR-30c suppressed P19 cell differentiation by inhibiting the Shh signaling pathway and altered the balance between cell proliferation and apoptosis, which may result in embryonic cardiac malfunctions.

Effect of miR-20b on Apoptosis, Differentiation, the BMP Signaling Pathway and Mitochondrial Function in the P19 Cell Model of Cardiac Differentiation In Vitro

Objective

To explore the effect of miR-20b on apoptosis, differentiation, the BMP signaling pathway and mitochondrial function in the P19 cell model of cardiac differentiation in vitro.

Methods

A miR-20b over-expression vector, a miR-20b silencing vector and their corresponding empty vectors were constructed and transfected into P19 cells, separately. Stably miR-20b overexpressing and silenced P19 cell lines were successfully selected by blasticidin and puromycin, separately. The cells were induced to undergo apoptosis in FBS-free-α-MEM. The induced cells were examined by flow cytometry and measurement of their caspase-3 activities. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was used to evaluate the relative expression of marker genes of cardiomyocytes during differentiation, such as cTnT, GATA4 and ANP. QRT-PCR was also used to detect the mitochondrial DNA (mtDNA) copy number. We investigated the cellular ATP production using a luciferase-based luminescence assay. The reactive oxygen species (ROS) was determined by DCFDA (2’, 7’-Dichlorofluorescein diacetate) and the mitochondrial membrane potential (MMP) was elucidated by a JC-1 fluorescent probe, both using fluorescence microscopy and flow cytometer. The expression of BMP signaling pathway-related proteins were analyzed by Western blotting.

Results

Stably miR-20b overexpressing and silenced P19 cell lines were successfully obtained. MiR-20b overexpression increased apoptosis and promoted differentiation in P19 cells by promoting the activation of the BMP signaling pathway. In addition, miR-20b overexpression induced mitochondrial impairment in P19 cells during differentiation, which was characterized by lower MMP, raised ATP synthesis and increased ROS levels. The effects of miR-20b silencing were the exact opposite to those of overexpression.

Conclusion

Collectively, these results suggested that miR-20b was very important in apoptosis, differentiation and mitochondrial function of P19 cells. MiR-20b may represent a new therapeutic target for congenital heart diseases and provide new insights into the mechanisms of cardiac diseases.

Factors affecting the feasibility of routine first-trimester fetal echocardiography

OBJECTIVES

The purpose of our study was to assess the factors that may improve the feasibility of routine fetal echocardiography at the time of the first-trimester scan.

METHODS

In this prospective study, we included 616 healthy singleton fetuses. Examinations were performed transabdominally by a single sonographer at the beginning of his training in first-trimester screening. The fetal heart was examined by high-definition color Doppler imaging to obtain the 4-chamber view, right and left ventricular outflow tracts, and 3-vessel and trachea view. Logistic regression was used to investigate the effect on the ability to visualize different cardiac structures.

RESULTS

The frequency of successful heart examinations increased significantly with the number of scans performed (P < .05). The sonographer needed 180 examinations before he could successfully examine the heart in at least 80% of cases. Significant factors that increased the probability of adequate echocardiography were the length of the heart examination and the experience of the sonographer (P< .05) but not transducer-heart distance, maternal body mass index, fetal crown-rump length, placenta interposition, or restrictive fetal position. Visualization of the left ventricular outflow tract could be improved by increasing the experience of the sonographer and decreasing the transducer-heart distance. Also, visualization of the 3-vessel and trachea view depended on the length of the heart examination, the experience of the sonographer, an anterior position of the placenta, and a restrictive fetal position.

CONCLUSIONS

Competence in color flow mapping assessment of the fetal heart at gestational ages of 11 weeks to 13 weeks 6 days is achieved only after extensive supervised training.

Imaging the first trimester heart: ultrasound correlation with morphology

First trimester sonography is a widely used technique to examine the foetus early in pregnancy. The desire to recognise complex anatomy already in early developmental stages stresses the need for a thorough knowledge of basic developmental processes as well as recognition of cardiac compartments based on their morphology. In this paper, we describe the possibilities and limitations of sonographic assessment of the foetal heart between 10 and 14 weeks of gestation and correlate this to morphology. Examples of the most commonly detected congenital anomalies are atrioventricular septal defects, transposition of the great arteries, and hypoplastic left heart, which are shown in this paper.

Fetal heart assessment in the first trimester of pregnancy: influence of crown-rump length and maternal body mass index

OBJECTIVE

To evaluate the influence of the crown-rump length and body mass index on sonographic evaluation of the fetal heart using abdominal and vaginal routes in the first trimester of pregnancy.

METHODS

We conducted a cross-sectional study with 57 pregnant women between 12-14 weeks (CRL< 84 mm). We evaluated the following fetal cardiac plans using the abdominal and vaginal routes: four-chamber view, right ventricle outflow tract, left ventricle outflow tract and aortic arch. We used the B-mode, color Doppler and four-dimensional ultrasonography (spatio-temporal image correlation). To evaluate the influence of crown-rump length and body mass index in the assessment of fetal cardiac planes, we used the t test unpaired.

RESULTS

There were no statistically significant differences in the rates of success and failure between abdominal and vaginal routes in relation to body mass index, however, there was a higher failure rate in vaginal assessment using B mode associated with color Doppler (P<0.01).

CONCLUSION

The crown-rump length and body mass index had no interference in fetal cardiac assessment in the first trimester of pregnancy.

Nuchal translucency and major congenital heart defects in fetuses with normal karyotype: a meta-analysis

OBJECTIVE

To pool published data regarding the sensitivity and specificity of nuchal translucency (NT) in the diagnosis of major congenital heart defects (CHDs) in fetuses with normal karyotype.

METHODS

MEDLINE and Scopus searches using combinations of the terms 'nuchal' and 'cardiac*' were complemented by perusal of references of the retrieved articles and an additional automated search using the 'search for related articles' function on PubMed. Only fetuses with normal karyotype and major CHDs were analyzed. Weighted estimates were made and summary receiver-operating characteristics curves were constructed.

RESULTS

The analysis included 20 studies (205 232 fetuses; 537 cases with major CHDs). The pooled sensitivity and specificity of NT > 95(th) centile for diagnosis of major CHDs was 44.4% (95% CI, 39.5-49.5) and 94.5% (95% CI, 94.4-94.6), respectively. The pooled sensitivity and specificity of NT > 99(th) centile was 19.5% (95% CI, 15.9-23.5) and 99.1% (95% CI, 99.1-99.2), respectively. For the subgroup of studies in which NT was measured by Fetal Medicine Foundation-certified operators, the pooled sensitivity and specificity of NT > 95(th) centile was 45.6% (95% CI, 39.6-51.7) and 94.7% (95% CI, 94.6-94.9), respectively. The corresponding estimates for NT > 99(th) centile were 21.0% (95%CI, 16.5-26.1) and 99.2% (95% CI, 99.2-99.3). The pooled positive likelihood ratio for NT > 99(th) centile was 30.5 (95% CI, 24.3-38.6). There was high across-studies heterogeneity for most estimates.

CONCLUSION

Approximately 44% of chromosomally normal fetuses with CHDs have NT > 95(th) centile and 20% have NT > 99(th) centile. However, there is high heterogeneity across studies, which largely remains even in subgroup analyses of studies of apparently similar design, potentially indicating the presence of some residual unidentified bias.