|Year : 2020 | Volume
| Issue : 2 | Page : 103-110
Prenatal echocardiographic diagnosis of congenital heart disease in high-risk antenatal mothers in a tertiary care center and their postnatal outcome: An experience from third world
Amber Bashir Mir1, Kaisar Ahmed1, Farhat Jabeen2, Muzafar Jan1, Sitaraman Radhakrishnan3
1 Department of Paediatrics, GMC, Srinagar, Jammu and Kashmir, India
2 Department of Gynaecology and Obstetrics, GMC, Srinagar, Jammu and Kashmir, India
3 Fortis Escorts Heart Institute, New Delhi, India
|Date of Submission||21-Feb-2019|
|Date of Decision||01-Mar-2019|
|Date of Acceptance||13-Jun-2019|
|Date of Web Publication||4-Aug-2020|
Dr. Amber Bashir Mir
Department of Paediatrics, GMC, Srinagar, Jammu and Kashmir
Source of Support: None, Conflict of Interest: None
Background: Congenital heart diseases (CHDs) are the most common fetal congenital defects, and until nowadays, most of them are bypassed without prenatal diagnosis. In this study, we found the incidence of fetal CHD in high-risk mothers, various indications of fetal echocardiography (FE), and their postnatal outcome in developing nation with limited resources.
Materials and Methods: A total of 106 cases of antenatal mothers, who are having risk factors such as abnormal obstetric screening, diabetes mellitus, and family history, are included in the study group. The FE was done for pregnant mothers between the age groups of 20 and 40 years at different gestational ages after 20 weeks of pregnancy in the Postgraduate Department of Pediatrics, GMC, Srinagar, between January 2016 and January 2018.
Results: The mean gestational age at diagnosis was 30.63 ± 4.3 weeks. The mean age of mothers at diagnosis was 29.99 ± 3.6 years. We identified indications for FE in 106 cases. The most common indication was abnormal cardiac findings in obstetrical screening sonography (30.18%). Among the 106 FE results, 80 (75.47%) were normal, eight (7.54%) were minor abnormalities, three (2.8%) were significant cardiac anomalies, eight (7.5%) were complex cardiac anomalies, and 60.7 (6.6%) were arrhythmias. The most common CHD was hypoplastic left heart syndrome (n = 4). Ninety-one neonates were examined by postnatal echo. We analyzed differences between FE and postnatal echo. There were minor differences in nine cases (9.89%) and major in only two (2.19%) cases. Transplacental fetal therapy was given in four cases. Two cases had fetal tachycardia that was reverted to sinus rhythm and two cases had complete heart block in which heart block persisted despite transplacental therapy.
Conclusion: FE is a very useful tool for prenatal diagnosis of CHD. It has proven itself in the diagnosis and management of fetal arrhythmia, even in developing countries with limited resources.
Keywords: Congenital heart defect, fetal echocardiography, prenatal diagnosis, ultrasonography
|How to cite this article:|
Mir AB, Ahmed K, Jabeen F, Jan M, Radhakrishnan S. Prenatal echocardiographic diagnosis of congenital heart disease in high-risk antenatal mothers in a tertiary care center and their postnatal outcome: An experience from third world. Heart India 2020;8:103-10
|How to cite this URL:|
Mir AB, Ahmed K, Jabeen F, Jan M, Radhakrishnan S. Prenatal echocardiographic diagnosis of congenital heart disease in high-risk antenatal mothers in a tertiary care center and their postnatal outcome: An experience from third world. Heart India [serial online] 2020 [cited 2020 Sep 19];8:103-10. Available from: http://www.heartindia.net/text.asp?2020/8/2/103/291365
| Introduction|| |
Congenital heart diseases (CHDs) are the most common abnormalities in fetuses, being six times more common than chromosomal abnormalities and four times more common than neural tube defects. The incidence of CHD with intrauterine diagnosis ranges from 2.4% to 54%.,,,,, Some countries have a high incidence of CHD because they have instituted an organized policy to perform heart screening by ultrasound systematically.,,
A detail evaluation of the fetal heart optimizes the diagnosis of CHD. This provides an appropriate prenatal and postnatal planning, enabling an improvement in neonatal morbidity and surgical outcome.,,,,
The use of fetal echocardiography (FE) for prenatal diagnosis has increased since it was introduced in 1964. Prenatal diagnosis with FE has improved the preoperative condition, morbidity, and mortality of patients with CHD. FE is now widely used in pediatric cardiology and perinatology and even for fetal cardiac intervention.
FE is a method, which takes long time, requires highly skilled and experienced investigators, and is costly. There is no chance to perform FE to all pregnant women in developing countries. As a result of this, it is very important to define the pregnant women who need FE in such a situation.
In this study, we evaluated reasons for referral of pregnant women who underwent FE, incidence of fetal CHD, effects of transplacental fetal therapy, and their postnatal outcome.
| Materials and Methods|| |
The present prospective study was conducted in the tertiary-level medical college teaching hospital, between January 2016 and January 2018. Ethical clearance was obtained from the Institutional Ethical Clearance Committee. A total of 106 pregnant mothers, who have undergone FE evaluation between 18 and 32 weeks of pregnancy, were enrolled in the study. We created a classification system for indications based on the indications reported by Jone and Schowengerdt. The two major categories of indications were fetal risks and maternal. We further classified fetal risks into six subcategories:
- Abnormal cardiac findings of obstetric screening ultrasonography (USG)
- Abnormal extracardiac findings of obstetric screening USG
- Fetal dysrhythmia
- Suspected chromosomal anomaly (increased nuchal translucency at the first trimester or abnormal triple or quadruple test)
- Other fetal risks (such as hydrops fetalis or fetal pericardial collection)
- In vitro pregnancy.
Maternal or familial risks included six subcategories:
- Maternal diabetes mellitus (DM) and gestational diabetes
- Previous child with CHD diagnosis
- Maternal systemic lupus erythematosus or lupus nephritis
- Maternal exposure to teratogen during pregnancy
- Previous history of CHD in sib
- Increasing maternal age >35 years.
Fetal hearts were examined by two-dimensional, pulsed, wave, and color Doppler echocardiographic methods using the Siemens Acuson S2000 machine equipped with a convex transducer. All examinations included a two-dimensional evaluation of cardiac structures with the “basic” (four-chamber view of the fetal heart) and the “extended basic” cardiac screening examination (views of the outflow tracts)., We also performed the ductal and aortic arch position, and we used the color Doppler. We assessed the cardiac situs, rhythm, venous inflow, atrial and ventricular chambers, atrioventricular and semilunar valves, and ventriculoarterial connections.,
Fetal echocardiography results and the postnatal outcomes in fetuses with congenital heart disease
Referring to the grading of the CHDs that Hunter et al. suggested, we defined five classes of FE results such as normal, minor abnormalities, significant, complex cardiac anomalies, and dysrhythmia classification system of fetal heart diseases used according to the complexity of the heart anatomical abnormalities.
- Complex: Heterotaxy or atrial isomerism, atresia or severe hypoplasia of a valve or chamber (hypoplastic left heart syndrome [HLHS], pulmonary atresia, tricuspid atresia, aortic atresia, mitral atresia, and Ebstein's anomaly), and abnormalities of the valve inlet or outlet (complete atrioventricular septal defect [AVSD], truncus arteriosus, double-inlet left or right ventricle, and double-outlet left or right ventricle congenitally corrected transposition of the great arteries)
- Significant: Transposition of the great vessels, tetralogy of Fallot (TOF), large ventricular septal defect (VSD), coarctation of the aorta, aortopulmonary window, critical aortic or pulmonary stenosis (PS), partial AVSD, total anomalous pulmonary venous connection, and tricuspid valve (TV) dysplasia (no Ebstein's anomaly)
- Minor: Small VSD and less severe aortic or PS, secondary dextrocardia/levocardia, pulmonary sequestration, and restrictive ductus arteriosus
- Dysrhythmias: abnormalities of cardiac rhythm.
The classification was adapted from Hunter et al. and Wren et al.
Comparison of prenatal and postnatal echocardiography results
We compared the results of fetal and postnatal echoes to assess the reliability of FE as a method for prenatal diagnosis. Based on Berkley's suggestions, we classified differences as a minor or major difference. A minor difference is one that does not result in a change in treatment plan, and a major difference does result in a change in treatment plan. If the surgical plan changed significantly, we identified the difference between fetal and postnatal echoes as a major difference.
| Results|| |
The 106 antenatal mothers who were included in the study, after identifying the risk factors, were categorised into groups according to their age. As per that, it has been found that the maximum number of patients belonged to the age group of 26–30 years, whereas the least number of patients presented between 20 and 25 years' age groups [Table 1].
[Table 2] depicts the gestational age at the time of diagnosis; majority of the women underwent echocardiography from 24 weeks to 32 weeks.
[Table 3] shows the indications for FE in 106 cases, in which 60 (56.6%) cases underwent fetal cardiac scan for fetal reasons while 46 (43.39%) cases for maternal indication. The most common indication was abnormal cardiac findings of obstetric screening (30.18%), and the second most common indication was maternal diabetes (26.4%).
|Table 3: Indication of the fetal echocardiography and frequency of congenital heart disease among them|
Click here to view
Distribution of congenital heart diseases diagnosed by fetal echocardiography
CHDs were diagnosed by FE in 26 fetuses. The distribution of CHDs diagnosed by FE was shown in [Table 4]. The cases were distributed in complex, significant, and minor defects and dysrhythmia according to the classification system by Hunter et al.: According to our study, we had eight cases each in the complex and minor group, seven cases in fetal dysrhythmia, and three cases in the significant group. The most common CHD was HLHS.
|Table 4: Distribution of congenital heart diseases diagnosed by fetal echocardiography|
Click here to view
[Table 5] depicts the FE results and the postnatal outcomes in fetuses with CHD.
Among the 106 FE results, 80 (75.47%) were normal, 8 (7.54%) were minor abnormalities, 3 (2.8%) were significant cardiac anomalies, 8 (7.5%) were complex cardiac anomalies, and 7 (6.6%) were arrhythmia. There were 26 diagnoses of CHD (minor, significant, complex, and dysrhythmia), and their clinical courses are outlined in [Table 5].
Of eight fetuses with minor cardiac anomalies, all babies were followed postnatally. A baby with restrictive ductus was delivered electively at 38 weeks; one baby with secondary dextrocardia died due to bilateral polycystic kidney. One baby with pericardial collection had significant respiratory distress and was admitted in the neonatal intensive care unit. One baby with TV dysplasia had severe tricuspid regurgitation and required antifailure treatment. Of three fetuses with significant cardiac anomalies, one with transposition of great vessels underwent arterial switch operation; one with Ebstein's anomaly died due to respiratory distress due to lung hypoplasia; and one with large inlet VSD and straddling TV had hypoplastic right ventricle later and had a staged operation for univentricular repair. Seven of 26 fetuses with complex cardiac anomalies were followed postnatally. We lost one fetus to follow-up. Pregnancy was aborted in four cases. One with HLHS was found to have aortic atresia with interrupted aortic arch died before any intervention. One with pulmonary atresia and VSD survived the neonatal period. One with complete AVSD was found to have complete AVSD with double-outlet right ventricle (DORV) and was put on antifailure drug and subsequently planned for surgical correction.
Among patients who had fetal tachycardia, one had structurally normal heart with short RP interval atrioventricular reentrant tachycardia and fetal ascites with moderate biventricular dysfunction. Fetal transplacental therapy (TPT) was started after admitting mothers in the hospital using intravenous digoxin loading, followed by oral digoxin along with oral sotalol. Rhythm was reverted to sinus rhythm, followed by decrease in fetal ascites along with improvement in ventricular function. The baby was delivered electively at 38 weeks through lower segment caesarean section (LSCS). Postnatally, the baby had normal sinus rhythm. Others had atrioventricular nodal reentrant tachycardia along with fetal hydrops and severe ventricular dysfunction and severe tricuspid regurgitation. TPT was given after admitting mothers in the hospital with intravenous digoxin, followed by oral digoxin and oral flecainide. Rhythm was reverted to sinus rhythm; there was a regression of fetal ascites but scalp edema persisted. A mother had early onset of labor and the baby was delivered prematurely at 36–37 weeks; the baby expired postnatally due to congenital hydrocephalus. Among two fetuses who presented with complete heart block (CHB), both had structurally normal heart: one received in utero sympathomimetic and another oral dexamethasone along with sympathomimetic. Postnatally, one baby developed signs of low cardiac output and hence had permanent epicardial pacemaker, and another baby had good ventricular rate and was kept under follow-up. Two cases with premature atrial contractions had normal sinus rhythm postnatally and one was lost to follow-up.
| Comparison of Prenatal and Postnatal Echocardiography Results|| |
For the 106 fetuses that underwent FE, 11 were lost to follow-up, 4 opted for medical termination of pregnancy (MTOP), and the remaining 91 underwent echo after birth. We compared fetal and postnatal echo results. The difference was minor in 8.7%. Major differences resulting in a change of treatment plan, especially surgery, occurred in only 2.19%. Cases with normal prenatal results that were diagnosed as small VSD, peripheral PS, patent ductus arteriosus (PDA), or patent foramen ovale (PFO) after birth were considered to have no difference in prenatal and postnatal echoes. There were two cases with major differences. The first was diagnosed as perimembranous VSD with straddling TV in utero, but the postnatal diagnosis was large VSD with straddling of TV and hypoplastic right ventricle. The second case was diagnosed as complete AVSD in utero, but the postnatal diagnosis was complete AVSD with DORV.
| Discussion|| |
In our study, it has been found that the maximum number of patients belonged to the age group of 26–30 years, followed by 36–40 years (24%). In our study, the number of women aged ≥ 36 is higher than in a study by Pradeep et al. As per the current information, elderly age could be an additive factor for the occurrence of CHD in the fetus in addition to other risk factors. In fact, in a study by Zhu et al., the advanced maternal age was the most common indication for FE.
In general, most of the fetal echocardiographies are done following fetal anomaly scan, usually at about 20–22 weeks of pregnancy. According to Caserta et al., the echocardiographic study of the fetal heart is optimally performed between 18 and 22 weeks of gestational age, a time window which enables the evaluation of most details of fetal cardiac anatomy. However, in our study, FE was done at various gestational ages for various indications, including late references by primary or secondary health-care centers for further evaluation. As per that in this study, majority of the echocardiographies were done between 28 and 32 weeks of gestation, followed by 20–24 weeks of gestation. The least number of patients presented between 32 and 36 weeks of gestation. There is a need for early referral for fetal cardiac scan, as with increasing maternal gestational age, detailed fetal cardiac visualization is difficult due to suboptimal echo windows.
We were able to identify indications for FE in 106 cases. Sixty cases underwent fetal cardiac scan for fetal reasons while 46 cases for maternal indication. The most common indication was abnormal cardiac findings of obstetric screening USG including the presence of intracardiac echogenic foci. According to Ozkutlu et al. in 2010, isolated echogenic focus is considered as a normal finding in the developing heart and hence is not considered as a pathologic symptom. In their study, they detected 17 cases of isolated echogenic focus in 1370 cases, and none of them had any CHD or Down's syndrome. The second most common indication was maternal diabetes including gestational diabetes comprising 26.4%. This was followed by suspected chromosomal anomaly and increased maternal age (8.4% and 6.6%, respectively). Indications for FE have changed with time. In the 1990s, the major indications for FE were a family history of CHDs, maternal DM, and arrhythmia.,, In 2004, Friedberg reported that the most common indication was a family history of CHD (23%), and the second most common indication was maternal DM (18%). Obstetrical ultrasound suspicious for CHD accounted for only 13%. Similar results were obtained by Meyer-Wittkopf et al. who reported that the most common indication for FE was a family history of CHD (44.5%). In the latter study, however, the second most common indication in 2001 was suspected CHD on obstetric scan (25.8%), instead of maternal DM. In these two studies, abnormal cardiac findings of obstetric screening USG accounted for 18% and 25.8% of indications, and these increased from 4% to 5% in the 1990s., Obstetric screening USG has recently found an even greater prevalence of cardiac abnormalities. Our results show that approximately 30% of all FEs were performed because of abnormal cardiac findings of obstetric screening USG. The distribution of indications can be expected to differ according to the institute and nation. Furthermore, the highest number of cases with CHD (n = 10, 83%) was among those antenatal women who underwent cardiac scan due to abnormal anomaly scan suggesting the need for timely referral of all pregnant women with abnormal Level 2 ultrasound scan.
The incidence of CHD in our study was 24.5% (n = 26). The prenatal incidence of CHD has a great variability ranging from 2.4% to 54%.,,,,,, This variability depends on the screening protocol and referral indications in different studies.
In general, isolated VSD is the most common CHD defect, and ASD is the second most common. Among cyanotic CHDs, TOF is considered most common. The most common CHD diagnosed prenatally in our study was HLHS, which is similar to a study by Berkley et al. and Boldt et al., There is a difference in the distribution of CHD diagnosed prenatally from those diagnosed postnatally. To explain this difference, we considered the detection rate of prenatal echo for certain CHDs. Zhang et al. showed that the prenatal detection rate for major defects requiring intervention or surgery during the 1st year of life is higher than the rate for minor defects (83% vs. 3%, P < 0.0001). This may be because the structural anomalies of complex CHDs can be detected much more easily by FE than those of simple CHDs.
In our study, of the 91 paired prenatal and postnatal echoes, 80 were normal before birth. Of the 80 neonates, 7 had CHD: 1 case of small VSD, 3 cases of mild peripheral PS, 2 cases of PFO, and 1 case of PDA. These are minor abnormalities that do not require change in treatment.
Many studies have mentioned discrepancies between prenatal and postnatal echo results. Berkley et al. qualified the degrees of the discrepancy. They reported that 3 (5.7%) of 53 paired prenatal and postnatal echo reports had minor variations and 3 (5.7%) had major variations. In comparison, we observed a lower rate of major differences (2.1%) and minor differences (9.1%). We could assume that minor differences are acceptable because they do not result in a change in treatment plan or surgical strategy. If we consider minor differences in the diagnosis of CHD to be acceptable, then the diagnostic accuracy of FE in our study is 97.8%. This is within the previously reported range of the diagnostic accuracy of FE (94.3%–99.0%).,
In our study, both patients with fetal tachycardia reverted with fetal TPT using combination of drugs. There was an improvement in fetal cardiac function and regression of fetal hydrops showing that early diagnosis and prompt referral is critical for better outcome. This is in concordance with a study by Karmegeraj et al. Both the cases with CHB mother were evaluated for autoimmune disease and were found to be anti-ds DNA positive in one case and anti-Ro anti-La antibody positive in another. Both the cases were given TPT. One woman received both dexamethasone and sympathomimetic drug, while in another case, dexamethasone was stopped in view of oligohydramnios. Both the neonates survived; however, one required permanent pacemaker. The use of fetal TPT in the management of isolated CHB has contributed importantly to significant improvement in fetal and neonatal mortality and morbidity.
| Conclusion|| |
FE is a very useful tool for prenatal diagnosis of CHD. It has proven itself in the diagnosis and management of fetal arrhythmia. FE helps in parental counseling and planning deliveries of affected babies in a tertiary cardiac center. This is especially important in developing countries like ours where there is scarce availability of pediatric cardiac care center.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
The ethical approval was obtained from the Ethical Clearance Committee of our institution.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]