Congenital heart disease (CHD) is the most frequent congenital disorder in newborns, and it is also the most common type of structural malformation of heart and large blood vessels [1]. Complex CHD refers to tetralogy of Fallot, pulmonary atresia, double outlet right ventricle, transposition of great arteries, left ventricular dysplasia, right ventricular dysplasia, complete anomalous pulmonary venous drainage, complete endocardial cushion defect, interrupted aortic arch and other complex cardiovascular malformations. There was an estimated incidence of 0.6% to 0.8% in China each year [2]. According to the National Center for Birth Defects Monitoring in China, the incidence of CHD has a steep rise from the fifth to the most common birth defect from 2005 to 2009 [3, 4]. The phenotype of CHD is usually related to other cardiac and/or extracardiac malformations and genetic syndromes [5]. Patients with congenital heart disease require surgical intervention, intensive medical management, and multidisciplinary follow-up [6]. In addition, serious CHD is one of the main causes of the death or disability of the newborn and children, which seriously affects the quality of the born population and brings heavy mental and economic burden to the family and society.

With the wide application of prenatal diagnosis, such as echocardiography, many fetal complex CHD can be diagnosed earlier and more accurately. According to the results of echocardiography, doctors can make a prediction and evaluation of the outcome and prognosis of these fetuses with complex CHD, and provide professional guidance for pregnant women and their families [7]. Furthermore, it has been reported that the postnatally diagnosed neonates with CHD were much more likely to present with cardiovascular compromise and multi-organ dysfunction [8].

In response, a CHD network has been established in our institution based on the integrated “prenatal diagnosis-postnatal treatment” model. Therefore, in the present study, we aimed to explore the clinical value and prognosis of the “prenatal diagnosis-postnatal treatment” model for fetuses with CHD by directly comparing the outcomes between prenatal and postnatal diagnosis.

As the most common birth defect in China, complex CHD is a major public health concern. It severely affects physical health, mental health, and quality of life of infants. It is also a major complication for family planning in China. Pregnancies in which the fetuses present a CHD have higgher rates of preclampsia, small for gestational age (SGA) and preterm birth [9]. Early diagnosis and treatment can reduce the morbidity and mortality rates of CHD in fetuses. In developed countries, the diagnostic rate of fetal CHD is as high as 90% and the cure rate with early intervention has reached 80% [2, 10]. In the past 8 years, a CHD network has been established in our hospital according to the integrated “prenatal diagnosis-postnatal treatment” model. Pregnancy termination should be considered for severe and untreatable cardiac defects to reduce the birth rate and postnatal death rate of infants with complex CHD. Almost half of infants with complex CHD can be diagnosed within 28 weeks of pregnancy. For certain complex CHD cases, the decision to induce labor or perform scheduled cardiac surgery is determined after comprehensive consultation between the mother and her physicians [11]. For CHD infants scheduled to receive treatment, the delivery mode can be chosen according to the physician’s advice, and vaginal delivery is usually the safest option [12].

In this study, 56 pregnant women whose fetuses was diagnosed as CHD by prenatal diagnosis chose induced labor to the termination of pregnancy in the 4–5 months of pregnancy, which eliminated the births of fetuses with severe life-threatening CHD, while postnatal diagnosis failed to avert the birth of infants with severe or untreatable complex CHD. However, early screening and treatment of CHD cannot be performed in many Chinese hospitals, especially primary hospitals. Thus, effective approaches for early prevention and treatment are urgently required.

In China, prenatal screening of fetal CHD mainly depends on fetal echocardiography. In recent years, new technologies, including three-dimensional and four-dimensional echocardiography, magnetic resonance imaging, and fetal magnetocardiography, have been adopted to improve the prenatal diagnosis rate [13]. In primary Chinese hospitals, many infants with complex CHD die soon after birth due to lack of expertise and medical technologies, and the surviving CHD infants must be referred to major centers for subsequent treatment. However, an array of issues may disrupt the efficient referral, including unclear referral pathways, lack of a referral network between large and primary hospitals, insufficient staff, and poor transportation equipment. Lack of accesses of diagnostic and therapeutic technologies for complex CHD leads many physicians in primary hospitals to abandon therapy for treatable CHD. In the present study, the diagnosis was not confirmed in the postnatal diagnosis group before admission to our institution. After diagnosis of complex CHD was validated, subsequent treatment was abandoned in 45 cases. While in the prenatal diagnosis group, treatment was terminated in only 10 of 126 (7.94%) cases. In addition, the number of infants eligible for follow-up was significantly higher in the prenatal diagnosis group than that in the postnatal diagnosis group (p 0.05), suggesting that accurate prenatal diagnosis and timely pregnancy termination can mitigate the harm to the mother and family and enhance the clinical prognosis of delivered infants.

Infants with CHD must be closely monitored during the neonatal period. Therefore, these infants should be delivered in the monitoring center of a tertiary hospital if possible to reduce the incidence of complications and ventilator time, and lower the risks conferred by antibiotics use and emergency surgery [14]. In this study, prenatal diagnosis of CHD was not associated with reduced preoperative or predischarge mortality, which was consistent with a previous finding [15]. Furthermore, the time to ventilator weaning after cardiac surgery and the length of postoperative hospital stay did not differ between the two groups. However, the number of infants with postoperative complications was significantly higher in the postnatal diagnosis group, which confirmed the certain safety advantages of “prenatal diagnosis-postnatal treatment”. The apparent discrepancy between actual complication rate and other complication indices may be due to the limited sample size and warrants further investigation. The outcome of fetuses with CHD shows and increase rata of SGA, particularly with small head circumpherence [16].

The results of this study are consistent with the previous findings that prenatal diagnosis of left ventricular dysplasia syndrome can significantly improve right ventricular function after birth and reduce the risk of metabolic acidosis and terminal organ dysfunction [17]. Prenatal counseling involves providing an accurate diagnosis of CHD, clearly explaining complex medical information to parents in crisis, including management options and outcomes, preparing parents for the delivery and disease course after birth, which supports them through the process of decision-making and throughout the pregnancy. Improved prenatal detection of CHD is needed in order to provide parents important opportunity for counseling and education to optimize outcomes in infants with CHD [18]. For newborns who were likely to benefit from treatment for critical CHD, such as the absence of additional risk factors and/or the family who was committed to treatment, prenatal diagnosis reduced the risk of death prior to planned cardiac surgery in comparison with infants with a comparable postnatal diagnosis [19]. Due to lack of prenatal diagnosis, some newborns with untreatable CHD are inevitably delivered, while others may not receive proper treatment during the neonatal period, especially if delivered at local hospitals. Therefore, the integrated model of “prenatal diagnosis-postnatal treatment” is highly recommended and derserves widespread application. In addition, the establishment of a monitoring network for complex CHD, including a standardized prenatal screening and diagnostic system, are key to improving coverage rate and postnatal outcomes.

In conclusion, integrated “prenatal diagnosis-postnatal treatment” model can confirm prenatal diagnosis, reduce complications after cardiac surgery, improve clinical prognosis, and decrease the birth rate of infants with untreatable complex CHD, thereby alleviating economic and emotional burdens on families.

SW and YJ contributed to the collection of data and writing the manuscript. LC, JH and FH contributed to analysis of the data and writing the manuscript. All authors approved the final version of the manuscript.

All subjects gave their informed consent for inclusion before they participated in the study. The study was conducted in accordance with the Declaration of Helsinki, and the research was approved by the Guangdong Provincial People’s Hospital Ethics Committee (No. GDREC2019657H).

Not applicable.

This study was supported by Guangzhou Science and Technology plan Major Project of Collaborative Innovation (NO. 201604020008) and Medical Science and Technology Research Fund Project of Guangdong Province (NO. A2020623).

The authors declare no conflict of interest.