The RADIUS trial concluded that routine prenatal ultrasound examinations have not been proven to impact fetal morbidity or mortality. The authors assert, however, that such clinical judgements must be based on basic ethical concepts. Through their examination of relevant ethical considerations, they urge that prenatal ultrasounds should be performed.
Frank A. Chervenak, MD and Laurence B. McCullough, PhD
is Acting Chairman and a Professor of Obstetrics and Gynecology
at The New York Presbyterian Hospital Cornell Medical Center, New
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.
The American College of Obstetricians and Gynecologists (ACOG)
supported this conclusion in the November 1993 Newsletter
and in the December 1993 Technical Bulletin
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.
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.
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
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.
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
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
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.
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."
In fact, the historical origins of primum non nocere remain
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.
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.
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.
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
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.
Instead, the clinical strategy of prenatal informed consent for
sonogram (PICS) should be employed with every pregnant woman.
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
In other words, PICS establishes a patient-based indication for
routine obstetric ultrasound.
The RADIUS investigators have explicitly opposed this indication
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
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.
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.
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
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,
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.
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
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.
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.
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.
They have maintained a narrow focus upon morbidity or mor-tality.
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