Applying Risk/benefit Analysis Consistently in Entertainment Ultrasound
By John C. Hobbins, MD, Professor and Chief of Obstetrics, University of Colorado Health Sciences Center, Denver, is Associate Editor for OB/GYN Clinical Alert.
Appearing in the December issue of Ultrasound in Obstetrics and Gynecology, an editorial by De Crespigny et al1 may rekindle the controversy surrounding keepsake videos and non-medical ultrasound, in general. At present, while some keepsake video businesses have continued to thrive, and providers are offering ultrasound for entertainment as part of, or in addition to, indicated scans, virtually all appropriate official medical organizations have continued to bolster their stance against these activities. The authors have separated entertainment scans into two types: those done during a medically indicated scan (MEU) and those performed separately for entertainment alone (non-medical entertainment ultrasound, NEU). De Crespigny and colleagues feel that to lobby against either type of non-medical ultrasound is "hypocritical" for a number of reasons.
If condemning NEU because of safety alone, one would have to take a schizophrenic approach to the issue of the bioeffects of ultrasound. In the many studies addressing this issue, either involving an in vitro cellular model, in animals, or in human investigation, there is no independently confirmed evidence to indicate harm to mother or fetus from ultrasound used at diagnostic dosage. Yes, one study did suggest a higher rate (5%) of "left-handedness" among male offspring exposed to ultrasound in utero compared with controls.2 Another study showed slightly lower birth weights (average of 25 g) in infants exposed to repeated Doppler ultrasound vs controls.3 However, later follow-up examinations found no difference in the size or neurodevelopment in these same children.4 The only other study, initially attracting attention, involved the exposure of pregnant mice to ultrasound at diagnostic intensities.5 Some of the offspring of those mice exposed to ultrasound for more than 30 minutes had 10% fewer brain cells than controls. However, the experimental method involved longer and more intense exposure to ultrasound, and in no way was similar to a typical examination in a pregnant woman. So based on all of the studies to date, we cannot completely preclude a subtle effect of ultrasound, but we can say that there certainly is no solid evidence to indicate that it does cause harm at diagnostic dosage.
Here is where the schizophrenia comes in. As De Crespigny and colleagues point out, based on the question of safety of ultrasound alone, we cannot have it both ways. Either it is safe or it is not, and whether it is done for an indication or for entertainment, it is the scan itself that is in question, and not the reason for the scan. They ask, why is it not justifiable to do a scan for entertainment, but it is acceptable to do an exam for teaching (a practice condoned by medical organizations)? They also point out that many women have multiple indicated exams and the addition of a single NEU, undertaken after organogenesis is complete, represents only a small contribution to the total exposure for that fetus.
As in any ethical debate, the authors predictably bring up the question of beneficence vs risk, but in this case we have to deal with two individuals, the mother and the fetus. For the sake of argument, they propose that we assume that the risk is "sufficiently high, or sufficiently uncertain" (far more likely) to scan only if there is benefit. Here they get into the uncomfortable area of fetal beneficence, and wind up pitting an indicated exam against NEU. They claim that, since the fetal survey in the indicated exam is designed to identify an anomaly, how can the fetus benefit from something that may lead to termination of pregnancy? Then they point out that many (unnecessary) fetal exposures are required to identify one anomaly. Unfortunately, the authors chose to ignore the huge fetal benefit of identifying a non-lethal abnormality or condition (like IUGR) where adjustment of the management can be lifesaving, or life-altering, for the fetus.
Regarding benefit to the mother, they imply that comparison between MEU and NEU is a wash. Both will reassure the mother, but the NEU may add the benefit of bonding. Here I strongly disagree. Most patients I see are "wired" before their first fetal anatomy scan, and are visibly relieved when we tell them there are no obvious abnormalities. This represents a strong benefit. Interestingly, the authors also wonder why the teaching exam is acceptable, when neither the fetus nor the mother benefits directly from this.
Based on all these inconsistencies, they conclude that "given the current practice, there is no good reason on the basis of bioeffects for opposing entertainment ultrasound."
What seems to have galvanized the medical organizations to take a position against ultrasound for entertainment was Tom Cruise's purchase of an ultrasound machine for his own pleasure and the surfacing of many shopping mall ultrasound kiosks designed to stuff the pockets of their owners. The authors of the editorial made some good points, but glossed over some counter points. For example, I was surprised that they did not address some of the undesirable fallout from NEU, such as when a "technician" not trained in prenatal diagnosis has apprised the patient, erroneously, of a possible fetal anomaly, or, worse yet, when a patient whose fetus has an anomaly is so reassured by the NEU that she skips her indicated ultrasound. This definitely has happened, and, therefore, these false-positives and false-negatives cannot be ignored.
We tend to overlook the real reason that our patients head out to the shopping mall to shell out more than $200 for pretty pictures of their babies — because they think they are being shortchanged during their routine ultrasound examinations in their providers' offices. This desire could be satisfied with a few extra minutes of 4D (or even 2D) enjoyment at the end of each examination. Today's delivery of care system has evolved to a point where we often seem to find ourselves in an adversarial position with our patients. What better way to counter this tendency than by fostering another type of bonding — provider/patient bonding — through this simple activity.
- De Crespigny L, et al. Risky business: Applying risk/benefit analysis consistently in entertainment ultrasound. Ultrasound Obstet Gynecol 2009;34:613-615.
- Salvesen KA, Eik-Nes SH. Ultrasound during pregnancy and subsequent childhood non-right handedness: A meta-analysis. Ultrasound Obstet Gynecol 1999;13:241-246.
- Newnham JP, et al. Effects of frequent ultrasound during pregnancy: A randomised controlled trial. Lancet 1993;342:887-891.
- Newnham JP, et al. Effects of repeated prenatal ultrasound examination on childhood outcome of to 8 years of age: Follow-up on randomised controlled trial. Lancet 2004;364:2038-2044.
- Ang ES Jr, et al. Prenatal exposure to ultrasound waves impacts neuronal migration in mice. Proc Natl Acad Sci U S A 2006;103:12903-12910.