Z-Score in Fetal Echocardiography–Is there Still Room for New Studies?

Congenital heart disease(CHD)is the most common type of birth defect,representing a significant cause of peri-natal morbidity and mortality.Early diagnosis of such anomalies is crucial for improving outcomes.Current pro-tocols recommend a qualitative assessment of cardiac structures using two-dimensional ultrasound(2DUS)and color Doppler imaging.In cases of suspected abnormalities,quantitative assessments through cardiac structure measurements and reference curves can aid in accurate diagnosis.Similar to centiles widely employed in obste-trics,Z-scores provide more precise quantification of various cardiac structures,particularly at the extremes of the curve.While the development of reference curves and Z-scores has progressed over the past two decades,a lack of standardization in measurements and statistical methodology for their determination is evident.Establishing reference curves requires adherence to specific recommendations to improve their accuracy.The purpose of this study is to provide a narrative review of the major studies that have generated reference values for cardiac struc-tures using 2DUS and Z-scores,to evaluate their methodology,and to provide a summary of the results.

Comparison study of harmonic imaging （HI） and fundamental imaging （FI） in fetal echocardiography

Objectives: To directly compare the quality of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography and to determine any differences in image quality between the two modalities. Methods: Fetal echocardiograms were performed with the use of FI and HI in 58 fetuses, image quality and visualization of left and right atria, left and right ventricles, mitral and tricuspid valves, aortic and pulmonary valves, left and right ventricular outflow tracts were evaluated and compared between FI and HI. Results: Mean HI scores were higher than mean FI scores (2.73±0.43 vs 2.16±0.69, P <0.001)for all the cardiovascular structures evaluated. Compared with FI, HI improved the image quality and visualization of fetal cardiac structures in subjects with both good (2.73±0.43 vs 2.88±0.32, P <0.001) and suboptimal (1.65±0.41 vs 2.58±0.47, P <0.001) echocardiographic windows. The interobserver correlation coefficient for the grading scores was 0.74 ( P <0.001). Conclusions: harmonic imaging enhances and improves the image quality of fetal echocardiography; and has important potential role in cardiac imaging in the fetus.

Differential Diagnosis of Cardiac Malposition by Fetal Echocardiography

To explore the method and operating skill of fetal echocardiography in diagnosing cardiac malposition.Methods 91 consecutive fetuses were studied （control： 50 cases, cardiac malposition ： 41 cases） between 2003 and 2008. The position of fetal heart was evaluated according to the fetal posture and the visceral situs by fetal routine scan- ning. The detailed echocardiography should be performed in the differential diagnosis of cardiac lesions when the heart was found to be abnormal position. Results In the control group, all fetuses were levocardia. 39 cases of cardiac mal- positions were detected by fetal echocardiography, included 25 fetuses with dextrocardia, 6 mesocard, 5 with levover- sion of heart, 3 common heart of conjoined twins and 2 extrathorax heart. Two of dextroversion were missed by fetal routine scanning, but found by autopsy or operation after birth. Conclusions When the abnormal visceral situs was found by fetal routine scanning , there is exceedingly high incidence of cardiac malpositions. Proficiently operating skill of fetal echocardiography is helpful to detect abnormal fetal cardiac position. （ S Chin J Cardiol2009 ; 10 （1） ： 23 -25）

CLINICAL SIGNIFICANCE AND PROGNOSIS OF FETAL ARRHYTHMIAS

Objective To explore fetal arrhythmia clinical significance and its correlation with fetal prognosis. Methods Twenty-six cases of fetal arrhythmia detected among 12 799 pregnant women recorded over a ten-year period in Peking Uinon Medical College (PUMC) Hospital were reviewed retrospectively. Fetal arrhythmia was diagnosed by fetal auscultation, ultrasonography, electric fetal heart monitoring, and fetal echocardiography. Results Twenty-six fetuses were documented with fetal arrhythmia (3 tachycardia, 4 bradycardia, 19 normal heart rate with irregular fetal cardiac rhythm). The incidence of fetal arrhythmia in our hospital was 0.2%. They were diagnosed at the average of 35 weeks’ gestation (15 to 41 weeks). Twenty-two cases were diagnosed by antenatal fetal auscultation, 1 case was diagnosed by ultrasonography, and 3 cases were diagnosed by electric fetal heart monitoring. Fetal echocardiograms were per-formed on 17 fetuses, 6 cases (35.3%) of which showed that ventricular premature beats with normal structure of fetal heart. All neonates survived postnatally and 24 of them (92.3%) were followed up. Echocardiograms were performed for 16 neonates and 2 of them were identified as atrial septal defects with normal heart rhythms. The results of follow-up showed that the two patients had no apparent clinical manifestation. The echocardiogram showed that atrial septal defect obliterated already. Conclusion The prognosis is well for most of the fetuses with arrhythmias, with low incidence of heart deformation.

Morphological Features of Complex Congenital Cardiovascular Anomalies in Fetuses:as Evaluated by Cast Models

Accurate prenatal diagnosis of complex congenital cardiovascular anomalies, vascular ones in particular, is still challenging. A fetal cardiovascular cast model can provide a copy of the cardiac chambers and great vessels with normal or pathological structures. This study was aimed to demonstrate three-dimensional anatomy of complex congenital cardiovascular anomalies in fetuses by means of corrosion casting. Twenty fetuses with prenatal-ultrasound-diagnosed complex cardiovascular anomalies were enrolled in this study（19 to 35 gestational weeks）. Fetal cardiovascular cast models were made by a corrosion casting technique. The specimens were injected with casting material via the umbilical vein, and then immersed in strong acid after casting fluid was solidified, to disclose the geometries of cardiovascular cavities. Nineteen cast models were successfully made from 20 specimens. The casts distinctly showed the morphological malformations and spatial relationship between cardiac chambers and great vessels. One hundred and eleven abnormalities were revealed by casting in the 19 specimens, including 34 abnormalities located in the cardiac chambers（3, 4 and 27 anomalies in the atria, atrioventricular valves and ventricles, respectively）, and 77 in the great vessels（28, 20, 24 and 5 anomalies in the aorta and its branches, the pulmonary artery, the ductus arteriosus and the major veins, respectively）. Corrosion casting can display three-dimensional anatomy of fetal complex cardiovascular anomalies. This improves our understanding of related pathomorphology and prenatal diagnosis.

Incidence of congenital heart disease in Beijing, China

Background The incidence of congenital heart disease has been studied in developed countries for many years, but rarely in the mainland of China. Fetal echocardiographic screening for congenital heart disease was first performed in Beijing in the early 2000s, but the impact was not clear. The current study was undertaken to determine the incidence of congenital heart disease in Beijing, China and to estimate the impact of fetal echocardiography on the incidence of liveborn congenital heart disease.Methods The study involved all infants with congenital heart disease among the 84 062 total births in Beijing during the period of January 1 and December 31, 2007. An echocardiographic examination was performed on every baby suspected to have congenital heart disease, prenatally or/and postnatally.Results A total of 686 infants were shown to have congenital heart disease among 84 062 total births. The overall incidence was 8.2/1000 total births. Mothers of 128 of 151 babies diagnosed prenatally were chosen to terminate the pregnancy. Two of the 151 infants died in utero. A specific lesion was identified for each infant and the frequencies of lesions were determined for each class of infants （total births, stillbirths and live births）. The incidence of congenital heart disease in stillbirths and live births was 168.8/1000 and 6.7/1000, respectively. The difference between the incidence of total birth and the incidence of live birth was statistically significant （P 〈0.001）. Conclusions The incidence of liveborn congenital heart disease in Beijing is within the range reported in developed countries. Fetal echocardiography reduce significantly the incidence of liveborn congenital heart disease.

Prenatal Diagnosis of Right Dominant Heart in Fetuses： A Tertiary Center Experience over a 7-year Period

Background： Right dominant heart （RDH） in fetuses can occur with a number of cardiac as well as noncardiac anomalies. Analysis of the enlargement of the right cardiac chamber in the fetus remains a major challenge for sonographers and echocardiographers. The aim of this study was to report the experience with prenatal diagnosis of RDH in the fetuses over a 7-year period. Methods： Fetuses with prenatal diagnosis of RDH from July 2009 to July 2016 were evaluated in two different categories： according to the gestational age, Group I （n = 154, second trimester） and Group II （n = 298, third trimester）; and according to the fetal echocardiography diagnosis, Group A （n = 452, abnormal cardiac structure） and Group B （n = 90, normal cardiac structure）. Differences in categorical variables were assessed by Chi-square exact test and continuous variables were evaluated by independent Student＇s t-test or Mann Whitney U-test depending on parametric or nonparametric nature of the data. Results： Over a 7-year period, 452 fetuses were referred for the assessment of suspected RDH. Left-sided obstructive lesions were observed most frequently in the fetuses with RDH. When comparing Group I with Group II and Group A with Group B, the latter groups exhibited significant differences in the right/left ventricle （RV/LV） ratio （1.435 vs. 1.236, P = 0.002; 1.309 vs. 1.168, P = 0.047）, RV width Z-score （1.626 vs. 1.104, P〈 0.001; 1.553 vs. 0.814, P= 0.014）, and above ＋2 cutoff percentages （14.3% vs. 22.5%; P= 0.038; 21.5% vs. 12.2%, P = 0.046）. Multivariable logistic regression revealed no variables associated with perinatal survival. Conclusions： The study demonstrates that RDH warrants careful attention to the possible presence of a structural cardiac anomaly, especially left-sided obstructive lesions. A diagnosis of RDH is best supported by a combination of the RV Z-score and RV/LV ratio. Most of the fetuses with RDH and structurally normal hearts had favorable outcomes.

Prenatal ultrasonographic characteristics and prognosis of isolated redundant foramen ovale flap

Objective:To analyze the prenatal ultrasonographic characteristics and prognosis of the isolated redundant foramen ovale flap(RFOF).Methods:From January 2014 to December 2021,we collected data on fetal echocardiography analyses and perinatal outcomes for fetuses with isolated RFOF in Peking University People's Hospital.Results:We found that 0.31%(87/28308)of participants have RFOF.The four-chamber results of the foramen ovale flap(FOF)showed that it was stiff and extended>50%or reached the lateral wall of the left atrium(LA)in diastole.As seen from the foramen ovale(FO)channel and four-chamber views,the hypermobile and redundant flap were observed shrinking and stretching with the fetal cardiac cycle,which is similar to jellyfish.The lateral displacement of flow from LA to the left ventricle(LV)around the FOF on color doppler demonstrated thin linear blood flow from the right to left and a reversal of flow across FO.A uniphasic,but not biphasic,pattern of FOF displacement was observed on M-mode.Stages I(23/87)and II(51/87)had a higher ratio of ventricular disproportion than Stage 0(11/87)and III(2/87).We observed the RA/LA(right/left atrium)>1.2 in 53 cases(60.9%),RV/LV(right/left ventricle)>1.2 in 53 cases(60.9%),PA/AO(pulmonary/aortic artery)>1.2 in 53 cases(60.9%),and moderate or severe tricuspid regurgitation in 10 cases and moderate pericardial effusion in 2 cases(2.2%).Seventy-four RFOF cases had follow-up data.Neonatal death occurred in 2 cases;72 fetuses survived with normal or minor heart defects.Conclusion:RFOF should be considered if the left side of the heart of a fetus is smaller and related to hypermobile FOF.For isolated RFOF cases,a monthly follow-up is recommended to monitor arrhythmia or fetal hydrop status.Prompt treatment is recommended for those with adequate gestational age and lung maturity.