Strategy For Prenatal Diagnosis Of Congenital Heart Disease And Evaluation Of Its Effectiveness

Congenital heart disease (CHD) represents the most common form of severe congenital malformation, with an incidence of 6-8/1000 live births. Fetal echocardiography has been reported to be a feasible and effective technique for detecting and diagnosing congenital heart disease prenatally. The accuracy of fetal echocardiography examination is critical to correct perinatal management. Research in this field is of important significance to medical practice of perinatal cardiology.Part OneEvaluation of prenatal diagnosis of congenital heart diseases ObjectivesThe aim of this study was to evaluate the detection and accuracy of fetal echocardiography for congenital heart defects among high-risk populations.MethodsA prospective observational study of prenatal diagnosis of congenital heart disease was conducted in two tertiary obstetrics and gynecology hospitals between January 2003 and December 2004. Consecutive fetuses at risk of CHD underwent detailed fetal echocardiography during the study period. B-mode and colour/pulsed Doppler flow imaging were used in all cases. Follow-up was sought for all pregnancies. Indications for referral, maternal and gestational age at diagnosis, associated extracardiac anomalies as well as prenatal and postnatal diagnosis were recorded prospectively. By comparing prenatal and postnatal diagnoses, sensitivity, specificity, and predictive values were estimated.ResultsA series of 2063 high-risk fetuses underwent detailed fetal echocardiography during study period. The mean gestation age at examination was 26.5 weeks (ranged 16-42 weeks). The most common indications for fetal echocardiography were advancedmaternal age (31.7%), fetal arrhythmias (13.5%) and maternal infections (10.4%). 43 cases of fetal congenital heart disease were detected. Mean gestational age at prenatal diagnosis was 27.3 weeks (ranged 16-40 weeks). There were 3 false-negatives and 1 false-positive. The sensitivity, specificity, positive and negative predictive values were 92.1, 99.9, 97.2, and 99.8%, respectively. Diagnostic accuracy was 86.1%. A cardiac defect suspected on routine prenatal sonography accounted for the highest proportion of abnormal cases (67.4%). Associated extracardiac anomalies were present in 19.6% cases. As for pregnancy outcome, there were 24 (52.1%) terminations. 2.2% died in utero, 13% postnatally, and 28.3% survived.Conclusionsfetal CHD can be identified reliably by prenatal echocardiography. Possible CHD suspected heart defect noted on a screening obstetric sonogram is an important indication for fetal echocardiography. A sequential segmental approach is critical for correct evaluation of the cardiac malformation. The outcome of the patients is poor and a multidisciplinary approach is needed to the parental counseling and perinatal management planning.Part TwoThe role of three echocardiographic planes in prenatal diagnosis of common congenital heart diseaseObjectivesThe purpose of the study was to assess the value of the three echocardiographic planes: the four-chamber (4CV), five-chamber (5CV) and three-vessel (3VV) views in diagnosing fetal common congenital heart defects.MethodsThe echocardiographic records of fetal congenital heart diseases (CHDs) performed from 5/03 to 7/04 were reviewed retrospectively. Only cases with postnatal confirmation by echocardiogram or autopsy were included. The abnormalities detected in each view were analyzed and classified.Results26 fetuses with congenital heart defects were included in the study. The abnormalities include: atrioventricular septal defects, ventricular septal defect, univentricular heart, single atrium, hypoplastic left heart syndrome, Tetralogy of Fallot, double outlet right ventricle, complete and congenitally corrected transposition of the great arteries, truncus arteriosus, hypertropic cardiomyopathy and cardiac tumor. At least one plane shows abnormality in each case. Each specific cardiac defect has its typical finding in these three planes. 73% of cardiac defects were noted on the two-dimensional (2D) four-chamber view examination. 7 cases of conotruncal malformation had normal 4CV by 2D scanning. Satisfactory 4CV, 5CV, 3VV were obtained in 96.2%, 88.5%, 84.6% of cases respectively.ConclusionsThe examination of the 4CV, 5CV, 3VV with Color Doppler provides essential information for the detection and diagnosis of fetal common CHDs. The application of these three planes has promising potential in the screening of fetal common CHDs. Compared with the two-dimensional four-chamber view for cardiac screening, a combination of three plane scanning may improve the detection rate of fetal CHD, especially of conotruncal anomalies.Part Three Cerebral vascular resistance in fetuses with congenital heart diseaseObjectiveThe aim of this study was to evaluate the significance of changes in cerebral vascular resistance in fetuses with specific CHD.MethodDoppler blood flow velocimetry was performed in the middle cerebral artery (MCA) and umbilical artery (UA) in 25 consecutive fetuses with isolated CHD. Gestation age ranged between 21 and 40 weeks. Fetuses with HLHS/AS/TGA (group 1, n=12) were separated from 13 fetuses with right-sided obstructive lesions (group 2). The control group comprised 100 healthy fetuses of uncomplicated pregnancies matched for gestational age. The cerebral-to-placental resistance ratio (CPR) was calculated.