Introduction

The title alone prompts the question: Is the failure to detect one of the most common critical heart defects in a fetus the result of an error by the individual physician performing the ultrasound examination or rather a consequence of the limitations of the entire prenatal diagnostic system?

D-transposition of the great arteries (d-TGA) accounts for approximately 5-7% of all congenital heart defects in fetuses and newborns and is one of the most common critical defects that may require intervention within the first few days of life [1-4]. In the absence of prenatal detection, the newborn may experience rapid decompensation following the physiological closure of the ductus arteriosus, and a delay in appropriate treatment is associated with an increased risk of severe hypoxaemia, metabolic acidosis, central nervous system damage, and death. Prenatal detection by an obstetrician, followed by targeted echocardiography at a tertiary centre, allows for planned delivery at a referral centre with paediatric cardiology and cardiac surgery services, initiation of appropriate pharmacological treatment, and, in selected cases, life-saving procedures such as balloon atrial septostomy [5-8], followed by arterial switch surgery. After appropriate treatment, the child may develop similarly to healthy peers.

Case history

A newborn was delivered by a healthy 32-year-old woman who had given birth to a healthy daughter two years earlier. The current pregnancy had no identified risk factors. An ultrasound examination at 12 weeks was described as normal. Karyotype results were normal. An ultrasound examination at 23 weeks was described as normal. At 32 weeks, another ultrasound examination was also described as normal. At 39 weeks of gestation, a male newborn weighing 3500 g was delivered vaginally with an Apgar score of 9/10. After birth, the newborn developed cyanosis, followed by circulatory failure. Postnatal echocardiography revealed d-TGA. The newborn required urgent treatment and immediate transport to a cardiac surgery centre 150 km away. A Rashkind procedure was performed on day 1. The newborn developed renal and hepatic failure. Cardiac surgery was performed while the newborn was in critical condition on day 8 of postnatal life. After surgery, the newborn remained in serious condition, requiring prolonged intubation and experiencing renal and hepatic failure and encephalopathy. Finally…

The question that arose almost immediately was: Why was the defect not detected before birth? We hear this question often. Even more often, we hear the follow-up question: “Who is responsible for this?”.

Why d-TGA, specifically?

Prenatal diagnosis of d-TGA may change the prognosis. It allows for planning the delivery location, ensuring the presence of a neonatologist and a paediatric cardiologist, immediate administration of prostaglandin E1, performance of the Rashkind procedure without delay, and preparation for cardiac surgery [9, 10]. Numerous studies have shown that prenatal diagnosis of d-TGA reduces the risk of severe metabolic acidosis, hypoxic-ischaemic encephalopathy, and neonatal death [11-13]. It can therefore be said that, in the case of this defect, prenatal diagnosis does not merely provide additional diagnostic information; it is an integral part of treatment. Despite tremendous advances in prenatal diagnostics, the detection rate for d-TGA is improving but remains unsatisfactory (Table 1). For other fetal heart defects, such as HLHS, the prenatal detection rate currently exceeds 70-80% [14, 15].

This raises the question: Why does a defect of such great clinical significance remain so difficult to detect? The answer lies partly in the anatomy of the defect itself. The classic four-chamber view of the fetal heart usually appears normal. We do not observe abnormal ventricular dimensions, marked functional abnormalities, or significant asymmetries. The heart may appear completely normal. The abnormality only becomes apparent during the evaluation of the outflow tracts, the great vessel crossings, and the three-vessel and tracheal views. In practice, this means that a physician who limits the evaluation to the four-chamber view may have no clues suggesting the presence of a severe defect.

Table 2 presents the current state of knowledge according to the International Society of Ultrasound in Obstetrics and Gynaecology (ISUOG).

Let us consider the first part of the posed question. Does the failure to detect d-TGA indicate an error on the part of the obstetrician-ultrasonographer managing the pregnancy? The answer is not clear-cut. If the examination was performed in accordance with current standards (which are typically updated every 4–5 years) and included assessment of the four-chamber view, the outflow tracts, and the three-vessel view, but the defect was still not diagnosed, it is difficult to classify this as an error. Fetal cardiac examination is one of the most difficult and challenging aspects of prenatal diagnosis. Therefore, a distinction must be made between detection during fetal screening ultrasound and detection at expert centres.

Prenatal diagnosis never achieves 100% sensitivity. There are situations in which examination conditions are unfavourable, for example when the fetus is in a suboptimal position, the patient has significant obesity, or the quality of the ultrasound equipment is limited. In such cases, even an experienced specialist may fail to make the correct diagnosis. The situation is different when the examination is performed in violation of standards or when the required views are not assessed.

In such cases, we can speak of a diagnostic error resulting from the improper conduct of the examination. A missed prenatal diagnosis does not, by itself, establish negligence if the scan was appropriately performed according to the applicable standard of care.

The assessment for various situations is presented in Table 3.

The causes may arise at different levels. First, pregnant women may lack information about fetal echocardiography. This does not mean that every woman should be offered targeted fetal echocardiography; rather, information about expert fetal cardiology centres should be readily available. In many regions, patients still do not have easy access to referral centres specialising in prenatal cardiology. Second, the level of training varies among professionals who perform examinations in pregnant women. A distinction must be made between the following:

· Fetal heart screening performed as part of a general ultrasound examination by an obstetrician within 3 minutes (a complete ultrasound examination usually takes 15-20 minutes).

· A basic specialised fetal heart examination performed by an ultrasound technician/echocardiographer within 30 mi-nutes.

· A specialised, targeted echocardiographic examination performed by a prenatal cardiologist within 60-90 minutes.

So, can we really expect a single obstetrician or ultrasound technician to achieve a level of effectiveness that the system does not support? When discussing the failure to detect d-TGA prenatally, can we limit ourselves solely to evaluating the work of a single physician? The effectiveness of prenatal diagnosis is influenced by at least three interrelated areas of systemic responsibility.

The first is an organisational issue – encompassing access to testing at referral centres, the time allocated for testing, and the organisation of perinatal care.

The second is an educational issue – related to the level of training of those performing echocardiography and their knowledge of d-TGA markers.

The third is an economic issue – concerning the funding of prenatal cardiac testing, access to modern equipment, and opportunities for continuing education for staff.

Only by analysing all these elements can we objectively assess the causes of a missed prenatal diagnosis of the defect and identify areas requiring improvement.

However, the most important points are as follows:

· Information on the importance of basic and specialised fetal cardiac examinations and the dissemination of this information.

· The development of prenatal cardiology.

· Practical pre- and postgraduate training programs.

· Continuous quality assurance and audits focusing on missed or incorrect fetal heart assessments.

The greatest improvements are achieved by centres that conduct regular echocardiography training. Training is important, but equally important is the analysis of cases that were not detected prenatally; such analysis should be part of the system’s continuous improvement. The aim is not to assign blame, but to identify areas requiring improvement.

“The best treatment for a newborn with a critical heart defect is to diagnose the defect before birth, following appropriate detection.”

In the case of d-TGA, the question should not be: Who is to blame? A far more important question is: What can we do to ensure that this defect is detected and diagnosed before birth in the next pregnancy?

In prenatal cardiology, the goal is not to assign blame, but to identify causes. Only then can we improve the quality of cardiac diagnostics and enhance the safety of our youngest patients – even before they are born. Success does not lie in diagnosing every heart defect. Success lies in continuously reducing the number of defects that remain undiagnosed. And this is the responsibility of everyone – doctors, educators, healthcare system administrators, and the scientific community.

Modern medicine is increasingly moving away from a culture of assigning blame toward a culture of patient safety, which involves analysing adverse events with a view to preventing them in the future.

This may offer a new perspective on the evaluation of cases of prenatally undetected d-TGA.

The issue of a physician’s liability for failing to undertake appropriate diagnostic procedures in accordance with current medical knowledge was examined in Poland in a Supreme Court judgment of 12 June 2008, Case No. III CSK 16/08 concerning the lack of prenatal genetic testing aiming to diagnose Turner syndrome in the fetus. The Supreme Court stated that “The entitlement to undergo prenatal testing derives from a pregnant woman’s right to receive information concerning the condition of the fetus, any potential diseases or abnormalities affecting it, and the possibilities for their treatment during the prenatal period (Article 19 paragraph 1 point 1) and 2) of the Act of 30 August 1991 on Health Care Institutions, Journal of Laws (Dz.U.) No. 91, item 408, as amended).” “Pursuant to Article 19 paragraph 1 point 1) and 2) of the Act on Health Care Institutions, a patient has the right to receive healthcare services consistent with current medical knowledge and the right to be informed about their state of health. These rights correspond to the obligations imposed on physicians under Articles 31 and 37 of the Medical Profession Act, which require physicians to provide patients with clear and comprehensible information regarding their health condition, diagnosis, proposed and available diagnostic and therapeutic methods, as well as the foreseeable consequences of undergoing or foregoing such methods. Furthermore, where diagnostic or therapeutic doubts arise, the physician is obliged, either on their own initiative or at the patient’s request, if justified by current medical knowledge, to seek the opinion of an appropriate medical specialist. In light of these provisions, and given the undisputed fact established at the outset that the only diagnostic examination capable of confirming or excluding (in the case evaluated by the Supreme Court) the presence of Turner syndrome in the fetus was prenatal genetic testing, each of the defendant physicians had a statutory duty, on their own initiative, to refer the claimant for such testing. They were also required to inform her of the significance of the examination, the consequences of undergoing or declining it, and the possible effects of the suspected genetic abnormality of the fetus. The claimant had the right to receive reliable and comprehensible information concerning the suspected condition and the available genetic tests, and, above all, the right to obtain a referral for such testing free of charge, which she was free to accept or decline. As the Supreme Court held in its judgment of 13 October 2005 (Case No. IV CK 161/05, OSP 2006, No. 6, Item 71), every physician is under a duty to possess the appropriate professional competence and to provide patients with adequate information. Such competence must be genuine and substantive, enabling the physician to properly assess the patient’s condition and to apply the necessary diagnostic and therapeutic measures. Likewise, the duty to provide information must be fulfilled in such a manner as to equip the patient with sufficient and understandable information necessary for making an informed decision regarding further medical treatment. A patient has the right to make autonomous decisions concerning matters of fundamental personal importance, while it is the physician’s duty to provide reliable, objective, and comprehensible information enabling the patient to make such decisions, as well as to issue referrals for examinations necessary to establish an accurate diagnosis. The physician must perform these duties on their own initiative, because patients – who generally lack medical expertise – may be unaware not only of their own medical condition but also of the diagnostic methods available to clarify it. A physician’s failure to provide the required information, the provision of inaccurate or misleading information, or the failure to issue a referral for specialist examinations where such examinations are necessary to determine the patient’s condition constitutes negligence on the part of the physician. Each of the defendant physicians was therefore under a duty to provide the claimant with reliable information regarding the condition of the fetus and to issue a referral for prenatal genetic testing, while explaining its purpose, nature, method of performance, and any potential risks associated with the procedure”. Mirosław Nesterowicz in Commentary on the Judgment of the Supreme Court of 13 October 2005, Case No. IV CK 161/05. Published in: Orzecznictwo Sądów Polskich (OSP), 2006, No. 6, item 71. “In the context of the physicians’ conduct in the case, their failure to provide the claimant with reliable information about her health condition and the risks associated with her pregnancy, as well as their failure to refer her for prenatal testing despite the pregnancy being classified as high-risk and her first child having a genetic disorder, the Supreme Court made important observations regarding physicians’ fault that have broader significance. Traditionally, a physician’s fault has been understood to include negligence, failure to exercise due care, lack of skill, inattention, or undertaking treatment without the necessary qualifications. In this case, however, the Supreme Court expressly held that physicians have a duty to continuously improve their professional qualifications and to keep abreast of advances in medical science and technology, as required by Article 18 of the Act on the Medical Profession and Article 55 of the Code of Medical Ethics. The Court considered it particularly significant that ‘ignorance in this respect constitutes fault on the part of the physician.’ Accordingly, a physician cannot defend themselves by claiming that they were unaware of information that they could and should have known. Because patients have the right to make autonomous decisions concerning personal matters (…), it is the physician’s duty to provide them with reliable, objective, and comprehensible information that enables them to make an informed decision. Therefore, the Supreme Court made a second important finding, namely that “misinformation, unreliable information, as well as the absence of information, constitute fault on the part of the physician.”

The lawyer’s opinion cited above indicates that an undetected fetal heart defect may be attributable to the obstetrician-gynaecologist if the physician failed to inform the patient about the possibility of undergoing specialised fetal echocardiography. Deficiencies in the organisation of the perinatal care system do not, in themselves, provide an adequate explanation.

Both the obstetrician and the patient need to understand the difference between fetal cardiac ultrasonography and fetal echocardiography. Fetal cardiac ultrasonography, because of the limitations of the method, may not be sufficient for a comprehensive assessment of fetal cardiac development and function. Fetal echocardiography should be performed at least once per trimester, beginning from the 15^th week of gestation. This examination should be performed at a designated centre of excellence in fetal cardiology and echocardiography. A comprehensive fetal examination consists of ultrasonography and echocardiography (Figure 1).

Disclosures

Ethical considerations: none.

This research received no external funding.

The authors declare no conflict of interest.