Abnormal findings in fetal echocardiography and maternal disease: A cross-sectional study

Abstract Background Congenital cardiovascular malformation is the most common group of birth defects. Fetal echocardiography is highly sensitive and specific in the diagnosis of congenital heart disease in low- and high-risk populations. Objective This study aimed to assess abnormal findings in fetal echocardiography and maternal disease. Materials and Methods This cross-sectional study was performed on 114 pregnant women referred to Afshar hospital, Yazd, Iran from October 2016 to March 2017. All pregnant women underwent fetal echocardiography through fetal heart screening protocol, which is administered by the international society of ultrasound in obstetrics and gynecology guidelines. Data collected included referral cause, gestational age, maternal age, gravida, and final diagnosis after an accurate fetal echocardiography. Results The mean gestational age was 20 wk. The most common referral cause of pregnant women included diabetes (36.8%), fetal arrhythmia (14%), high maternal age (7%), and echogenic focus on ultrasound (6.1%). The most common postpartum findings were normal (68.4%), cardiac abnormalities (17.6%), and arrhythmias (14%). In postnatal echocardiography, the results were consistent with fetal echocardiography except in 2 women. Conclusion This study showed that fetal echocardiography can be used in the early diagnosis and treatment of congenital heart diseases.


Introduction
Congenital heart disease (CHD) is usually triggered by an abnormal development in the fetal heart structure in early embryonic stage (1). Some abnormalities may occur when the heart splits into 4 chambers and the valves form. Conotruncal disorders or valvular formation anomalies occur during these stages. These defects do not trigger prenatal or dynamic problems (2). Congenital vascular malformations are the most common group of birth defects and affect about 6-8 per thousand newborns (3). According to the previous studies, the prevalence of CHD is 6 times higher than chromosomal abnormalities and 4 times higher than neural tube defects. There are several risk factors involved in these diseases, which are generally divided into 2 categories maternal and fetal (4). In most cases, the cause is unknown; some are genetic, and some are environmental (5). Although in most cases they are multifactorial, several are also associated with chromosomal abnormalities, congenital defects, teratogens, or maternal metabolic disease. The range of lesions varies from asymptomatic to fatal anomalies (6).
Due to the high prevalence of congenital heart defects, fetal echocardiography is an important part of screening during pregnancy to diagnose fetal heart defects and arrhythmias (7).
Fetal echocardiography has high sensitivity and specificity in diagnosing CHD in low-and highrisk populations (8). Fetal echocardiography is considered a standard part of pregnancy services (9). Techniques such as fetal heart magnetic resonance imaging and electrocardiogram are performed in only a few facilities due to their high cost and difficulty of access and are used only in research protocols. Fetal cardiac magnetic resonance imaging and fetal electrocardiography alternatives are acceptable procedures in diagnosing fetal atrial and ventricular arrhythmias (10). Although in fetal echocardiography, it is impossible to calculate details such as the pwave axis or the width of QRS and QT C interval, the type of arrhythmia can only be identified based on changes in Doppler waves (11).
Moreover, in several other cases, such as fetal tachyarrhythmias, it is possible to prevent or treat heart failure by drugs prescribed to the mother.
Another application of echocardiography in the treatment of non-autoimmune hydrops associated with fetal heart failure is performed by prescribing high-dose digoxin to the pregnant mother and monthly follow-up (4). Also, with early diagnosis of these diseases, fetal heart interventions can be used to treat these defects. One of the most successful of these interventions is transplacental drug therapy to treat fetal tachyarrhythmias (7). Therefore, this study aimed to assess abnormal findings observed in fetal heart based on echocardiography and maternal disease.

Materials and Methods
This cross-sectional study was performed on

Statistical analysis
The qualitative variables were reported as frequency and percentage. Data were analyzed by SPSS19 (IBM Corporation, New York, USA).    had a history disease in their previous children or fetuses. Cardiac abnormalities were observed in all 6 cases. Also, 2 cases (1.8%) were referred due to drug use in the mother; one of which (0.9%) was diagnosed with cardiac abnormality (Table III) (Table III).

Discussion
In this study, of 114 referred pregnant women, the most common reason for fetal echocardiography was diabetes (36.8%), 14% of referrals were due to fetal arrhythmia, and 49.2% were because of other problems. The results of fetal echocardiography revealed that 68.4% of cases were normal, 17.6% had cardiac anomalies, and 14% had abnormal cardiac rhythm.
In fetal echocardiography, we are faced with a host of images that fail to be sequenced, all of which may lead to errors in the correct diagnosis of fetal heart abnormalities or arrhythmias, thus warning us of the need for postnatal follow-up echocardiography (12).
In this study, the prevalence of CHD was 13.1%.
However, in a study that had examined 1,200 cases of pregnancy for a year, the incidence of CHD was reported to be 15 per 1,000 births (4). In the present study, the mean age of the Also, Sharma and colleagues reported a complete association between the 2 echocardiography amounting to 68.17% (4). Further, in another study, the sensitivity and specificity of the method were expressed as 85.5 and 100%, respectively (18).

Conclusion
This study showed that fetal echocardiography is a non-invasive method suitable for early diagnosis of CHDs with high sensitivity and specificity, being appropriate in high-risk and lowrisk pregnancies. Also, it could be employed in early diagnosis and treatment of CHD if present or in abortion therapy.