Applied Radiology

Frank A. Chervenak, MD and Laurence B. McCullough, PhD

Dr. Chervenak is Acting Chairman and a Professor of Obstetrics and Gynecology at The New York Presbyterian Hospital Cornell Medical Center, New York, NY. Dr. McCullough is a Professor of Medicine and Medical Ethics at Baylor College of Medicine, Houston, TX.

Whether all pregnant women should have an ultrasound examination continues to be controversial. This question has been answered affirmatively in most of Europe and the rest of the world. We will argue that ultrasound should be offered to all pregnant women.

The RADIUS trial remains the largest and most expensive prospective study of the routine use of obstetric ultrasound. Screening ultrasound was found not to significantly improve perinatal or maternal outcome and the investigators concluded that routine obstetric ultrasound was not indicated. ¹ The American College of Obstetricians and Gynecologists (ACOG) supported this conclusion in the November 1993 Newsletter ² and in the December 1993 Technical Bulletin ³ on Ultrasonography in Pregnancy. The Bulletin states that "... in the United States the routine use of ultrasonography cannot be supported from a cost-benefit standpoint." The newsletter adds that ";... the College not recommend routine ultrasound screening." There is no uniform support for this stance. Critics have pointed out scientific shortcomings in both the methods and conclusions of the RADIUS trial. ^4,5

There is another unstated concern that needs to be addressed. In the authors' view, ethics is an essential dimension of the routine obstetric ultrasound debate. ⁶ This is not so much a clinical issue to which there are ethical aspects, but rather it is a clear example in modern obstetrics in which widespread ignorance of basic ethical concepts can lead to inappropriate clinical judgment.

A primer on medical ethics

Ethics can be defined as the disciplined study of morality. Morality concerns both right and wrong behavior (i.e., what one ought and ought not to do), and good and bad character (i.e., virtues and vices). Since the goal of ethics is to improve human behavior and character, the fundamental question that ethics addresses is, "What ought morality be?" This question involves two further questions, "What ought our behavior be?" and "What virtues ought to be cultivated in our moral lives?" Medical ethics deals with these same questions, focusing on what morality ought to be for physicians.

The bedrock for what morality ought to be in clinical practice for centuries has been the obligation to protect and promote the interests of the patient. There are two perspectives in terms of which the patient's interests can be understood: that of the physician and that of the patient. ⁶

The first of these two perspectives on the interests of patients in the history of medical ethics is the perspective of medicine. On the basis of scientific knowledge, shared clinical experience, and a careful, unbiased evaluation of the patient, the physician should identify those clinical strategies that will likely serve the health-related interests of the patient and those that will not do so. The health-related interests of the patient include preventing premature death and preventing, curing, or at least managing disease, injury, handicap, or unnecessary pain and suffering. That these matters are constitutive of any patient's health-related interests is a function of the competencies of medicine as a social institution. ⁶ We cannot overemphasize the point that the identification of a patient's interests is not a function of the personal or subjective outlook of a particular physician, but rather of rigorous clinical judgment.

The ethical principle of beneficence obliges the physician to seek the greater balance of goods over harms for patient care. On the basis of rigorous clinical judgment, physicians should identify those clinical strategies that are reliably expected to result in the greater balance of goods (i.e., the protection and promotion of health-related interests), over harms (i.e., impairments of those interests). The principle of beneficence has an ancient pedigree in Western medical ethics, at least back to the time of Hippocrates. ⁶

The principle of beneficence in medical ethics should be distinguished from the principle of nonmaleficence, commonly known as "primum non nocere" or "first, do no harm." It is important to note that primum non nocere does not appear in the Hippocratic Oath or in the texts that accompany the Oath. Instead, the principle of beneficence was the primary consideration of the Hippocratic writers: "As to diseases, make a habit of two things-to help or to at least do no harm." ⁶ In fact, the historical origins of primum non nocere remain obscure. ⁶

There are more than historical reasons to reject primum non nocere as a principle of clinical ethics, because virtually all medical interventions involve unavoidable risks of harm. If primum non nocere were to be made the primary principle of clinical ethics then invasive radiological procedures would be unethical, an obviously absurd conclusion.

Primum non nocere is therefore super-seded in medical ethics of maternal-fetal medicine by the principle of beneficence. The latter is sufficient to alert the physician to those circumstances in which a clinical intervention has the potential to harm the patient. When a clinical intervention is on balance harmful to a patient, it should not be employed.

A well-formed clinical perspective on the interests of the patient is not the only authoritative perspective on those interests, because the perspective of the patient on the patient's interests is equally worthy of consideration by the physician. Each adult pregnant patient has developed a set of values and beliefs according to which she is capable of making judgments about what will and will not protect and promote her interests. It is commonplace that in other aspects of her life the patient regularly makes such judgments concerning matters of considerable complexity (e.g., choosing a professional calling, rearing children, entering into contracts, and writing a will of property). Despite the complexity of these decisions, she is rightly assumed to be competent to make them, with the burden of proof on anyone who would challenge her competence. ⁶

The same is true regarding health care decisions made by the pregnant patient. She must be assumed by her physician to be competent to determine which clinical strategies are consistent with her interests and which are not. In making such judgments, it is important to note that the patient utilizes values and beliefs that can range far beyond the scope of health-related interests (e.g., religious beliefs or beliefs about how many children she wants to have). Beneficence-based clinical judgment, because it is limited by the competencies of medicine, gives the physician no authority to assess the worth or meaning to the patient of the patient's non-health-related interests. Therefore, these are matters solely for the pregnant patient to determine.

The ethical significance of this perspective is captured by the ethical principle of respect for autonomy. This principle obligates the physician to respect the integrity of the patient's values and beliefs, to respect her perspective on her interests, and to implement only those clinical strategies authorized by her as the result of the informed consent process. This process is understood to have three elements: 1) disclosure by the physician to the patient of adequate information about the patient's condition and its management; 2) understanding of that information by the patient; and 3) a voluntary decision by the patient to authorize or refuse clinical management. ⁷

Medical ethics and routine obstetrical ultrasound

Providing patients with information about diagnostic and therapeutic alternatives is an essential component of respect for the patient's autonomy. Failure to provide the patient access to information deprives the patient of the opportunity to consider alternatives about the management of her pregnancy, some of which may be highly in accord with her values. Nondisclosure of diagnostic alternatives therefore seriously impairs the exercise of the patient's autonomy. Routinely offering obstetric ultrasound respects the autonomy of pregnant women and not routinely offering obstetric ultrasound systematically disrespects the autonomy of pregnant women, because the woman's access to the diagnosis of serious anomalies and, therefore, access to abortion for serious fetal anomalies is restricted. ⁸ These matters are not ethically or clinically trivial.

The implication of respect for autonomy in clinical practice means that every pregnant woman should be informed of the availability of this diagnostic modality at the physician's initiative. ⁸ A practice of discussing ultrasound only when women initiate inquiries makes a sham of respect for autonomy because many women are informed about this modality and its ability to detect at least three times the background detection rate of fetal anomalies. ^1,8,9 Instead, the clinical strategy of prenatal informed consent for sonogram (PICS) should be employed with every pregnant woman. ⁸

PICS should be undertaken in several stages. Soon after the pregnancy has been diagnosed, the pregnant woman should be provided by her obstetrician with information about the actual and theoretical benefits and harms of obstetric ultrasound. The pregnant woman should then be given an opportunity to evaluate this information in terms of her own values, something every autonomous patient can do. It may be helpful to some women to consider, at this point in the process, the physician's scientific evaluation of the clinical data that have been reported in the literature. The pregnant woman should be asked to articulate her preference regarding the use of ultrasound in the management of her pregnancy. The physician should then provide the pregnant woman with the physician's own recommendation, and there should be discussion of any disagreement that may emerge. On the basis of the foregoing, the woman makes her final decision. This decision should then determine the use of obstetric ultrasound for that pregnant woman.

In other words, PICS establishes a patient-based indication for routine obstetric ultrasound. ⁸ The RADIUS investigators have explicitly opposed this indication ⁹ and ACOG, by its silence on this matter and its support of the conclusions of the RADIUS study, gives the appearance that it also opposes this indication. As a result, ACOG reduces the ability of physicians to be effective advocates for the autonomy of pregnant women regarding access to routine obstetric ultrasound. The authors propose that obstetricians act on their autonomy-based obligation to pregnant women and advocate for their autonomy by offering, and thereby providing, access to routine obstetric ultrasound.

Objections to routine ultrasound

There are two possible objections to our proposal: lack of benefit and excessive cost. We will show how each of these objections fails.

Lack of Benefits - Treating lack of benefit of routine obstetric ultrasound as decisive implies that beneficence-based considerations override autonomy-based considerations. The RADIUS trial, which applies to at most 40% of women who present for private obstetric care, found that routine ultrasound did not significantly improve outcome in terms of perinatal morbidity or mortality or maternal morbidity. ¹ This is only one measure of the efficacy of this diagnostic maneuver. Screening ultrasound has accomplished significant improvement in detection of fetal anomalies, detection of twin pregnancies, diminished usage of tocolysis, and reduction of the occurrence of postdatism. ^1,4,5 The RADIUS trial assumed that these possible benefits would be truly clinical benefits only if they had a documented improvement in perinatal morbidity and mortality. Although there are important measures, they do not represent the full array of clinical considerations.

Clinical judgment should not narrow itself only to the measurement of end points such as perinatal morbidity and mortality, but should also include the prevention of harm in small but important subsets of patients. The RADIUS study conclusions were slanted by an unjustifiably narrow concept of clinical judgment that is not acceptable in modern medical ethics. The study ignored other clinical realities (prevention of unnecessary tocolysis, early prenatal diagnosis of twin gestations not detected clinically, physician-patient ignorance of the presence of fetal anomalies prior to delivery, and inappropriate assignment of postdatism) that are also significant in and of themselves in clinical judgment. Ignorance of clinical realities is not bliss for either the patient or the physician. Lack of available information is not an acceptable standard of care.

In contrast to the narrow view adopted by the RADIUS study, the goal of modern medical ethics is comprehensive clinical ethical judgment. In such comprehensive clinical ethical judgment, the physician justifiably offers obstetric ultrasound as a matter of prudence to avoid rare adverse outcomes such as unnecessary tocolysis provided that such benefits outweigh the possibility of harm from erroneous ultrasound diagnoses. Prudential calculations in well-formed clinical judgment emphasize the seriousness of the outcome rather than the low incidence of the out-come. With respect to seriousness of outcome, the risks of not performing ultrasound are significant even though they are of very low incidence. For example, given the seriousness of the outcomes of undetected clinical complications, such as unexpected twins at the time of delivery, it is justifiably risk averse to attempt to prevent those out-comes when in clinical judgment the risks of not performing the ultrasound outweigh the risks of performing it. In the authors' view, high-quality ultrasound, ⁸ which is required as a matter of professional integrity, reduces the risk of harm from erroneous ultrasound and, therefore, tips the balance in favor of this prudential judgment.

This prudential judgment is not altered by concern for possible bioeffects. This is because there are no documented reproducible ill effects of obstetric ultrasound. Moreover, no credible study has documented a serious bioeffect. Therefore, in prudential clinical judgment, outcomes that remain theoretical have far less weight than serious outcomes that are documented.

An ethical analysis of routine ultrasound based on clinical judgment of the proper scope reaches two conclusions: 1) endpoints of overall perinatal morbidity and mortality are not the only relevant components of comprehensive clinical ethical judgment; and 2) prudential clinical ethical judgment supports offering highquality ultrasound. The first is neutral in the clinical judgment of PICS; the second supports PICS in clinical judgment. Thus, objection to PICS on the ground that it provides no benefit fails. Moreover, given the significance to the pregnant woman of the benefits of PICS, namely to make an informed choice about the management of her pregnancy, central matters of respect for autonomy are at stake. On balance, autonomy-based obligations should clearly be the physician's primary guide in response to objections based on lack of benefit.

Excessive Cost - Treating the excessive cost of routine obstetric ultrasound as decisive asserts that justice-based considerations or fairness override autonomy-based considerations. A central justice-based consideration is cost-effectiveness, which concerns identifying the least expensive means to achieve an agreed upon goal. An important goal of obstetric ultrasound is to detect fetal anomalies. Devore ¹⁰ has shown that the cost per detected case of an anomaly in the RADIUS trial was not greatly different from the cost per detected anomaly in the California MSAFP screening program. Given the improved detection rate in tertiary centers, Devore has shown that the cost per anomaly detected with quality ultrasound is much less. ¹⁰ The California MSAFP screening program is a reliable touchstone for cost-effectiveness. By this comparison alone, routine obstetric ultrasound is cost-effective.

A second justice-based consideration is cost-benefit which concerns whether the cost of an intervention in the present saves a greater cost in the future. We interpret Devore's analysis to suggest that routine ultrasound is cost beneficial because the cost per anomaly detected with quality ultrasound is far below the neonatal and lifetime costs of those anomalies, assuming that for many pregnancies in which serious anomalies are detected women will seek a termination.

Let us suppose for a moment that rou-tine obstetric ultrasounds were not cost beneficial. Should this consideration automatically override respect for auton-omy? Those who imply that the answer is "yes" confront a significant burden of proof. First, most theories of justice in Western philosophy give paramount consideration to personal autonomy and freedom, including theories of justice based on utilitarianism. It would mark a radical departure from this centuries-long history for the principle of justice to automatically override the principle of respect for autonomy. Justice-based con-siderations may override autonomy-based considerations when costs are enormous, even when some benefit results. This was not the case before, and is not the case after, the RADIUS study.

Conclusion

PICS, the routine offering of obstet-ric ultrasound, is the central issue in the routine obstetric ultrasound debate, because there is a decisive role for the exercise of the pregnant woman's autonomy to judge the benefits and harms of routine ultrasound and the worth to her of the information yielded by high-quality ultrasound. The authors of the RADIUS trial explicitly oppose PICS. ⁹ They have maintained a narrow focus upon morbidity or mor-tality. ^1,8 We have shown that these are important, but not the only components of comprehensive ethical judgment.

In order to avoid errors in clinical judgment that is less than comprehen-sive, physicians should be strong advo-cates for offering obstetric ultrasound to pregnant women. Some may view this as an extreme and expensive proposal. However, it asks no more for patients than virtually all physicians expect for themselves or family members as an essential part of contemporary obstetric care.     AR