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It has been more than 55 years since ultrasound was first described, and today’s tools and techniques barely resemble the initial construct.
Dr Levine is Practice Director at the Colorado Center for Reproductive Medicine, New York, New York.
As obstetricians and gynecologists we must know not only obstetrics and gynecology but also a significant amount of internal medicine, general surgery, and radiology. Knowing which radiologic test to order is not enough; many of us routinely make clinical decisions and perform procedures based solely on our own ultrasonographic findings.
Ultrasound was first introduced to ob/gyn in the late 1950s in an article published by Dr Ian Donald in the Lancet. In this sentinel paper, Donald described how an image of a fetus could be produced on a cathode ray tube by rocking a transducer slowly over a woman’s abdomen. This early image was bistable (meaning that it lacked any gray scale so it was completely black and white).1
It was Donald and his team who first described the early diagnosis of a hydatid mole, identification and assessment of early gestation, and presence of pelvic masses.2 In the years that followed, these investigators also made great advances in describing the location of the placenta. That was viewed as a paramount discovery because hemorrhage from placenta previa was then a significant cause of maternal and fetal morbidity and mortality.3
It has been more than 55 years since ultrasound was first described, and today’s tools and techniques barely resemble the initial construct. Ultrasounds are now performed in real time, transvaginal transducers allow for improved pelvic sonographic studies, and 3D constructs are a common component of fetal anatomical screening.
For example, GE Healthcare announced last year that it had released a machine (the Voluson E10) that in the company’s words has “4 times the ultrasound pathways for improved clarity with increased penetration, 10 times the data transfer rates for more speed, higher resolution and very fast frame rates, and 4 times the processing power for more flexibility with advanced applications and efficient workflow.”4
Do our patients really need all that technological power? Most likely not. Most patients who have 3D/4D ultrasounds are having the scans as “keepsake” mementos because they are excited about the opportunity to see a facial reconstruction of their fetus. A glimpse of their baby smiling or sucking his thumb while in utero is a moment parents don’t forget. However, the US Food and Drug Administration (FDA) has recently been vocal about avoiding such elective scans.
In an FDA statement released in 2014, Shahram Vaezy, PhD, an FDA biomedical engineer, is quoted as saying, “ultrasound can heat tissues slightly, and in some cases, it can also produce very small bubbles (cavitation) in some tissues.” The concern is that the long-term effects of tissue heating and cavitation are unknown. Therefore, the FDA recommends that ultrasound scans be done only when there is a medical need, based on a prescription, and performed by appropriately trained operators.5
This FDA opinion is focused on protecting the population as a whole-preventing patients from being taken advantage of financially, being reassured of normality from a non-diagnostic “study,” and keeping them from putting their unborn children at theoretical risk.
The Wall Street Journal reported that in 2014 the most common fetal-ultrasound procedures were performed an average of 5.2 times per pregnancy in the United States, up 92% from 2004; some women report getting scans at every doctor visit during pregnancy.6 The article goes on to say that the rising usage rates may in part reflect a belief among obstetricians that routine scans can help stave off “surprises.” Such “defensive” medical practices may be related the fact that obstetricians pay among the highest malpractice premiums of any medical specialty.
Indeed, the same WSJ article also noted, “experts in the field say it isn’t uncommon for lawsuits against obstetricians to allege that more ultrasounds should have been performed.”6
So if ultrasounds can legitimately aid in prenatal diagnosis, more precisely diagnose gynecological disorders and perhaps prevent litigation, are all ob/gyn residents comfortable using ultrasound to its full potential upon completing training? A recent evaluation of the quality of ultrasound education in Canadian ob/gyn residency programs found that most residents reported inadequate exposure to gynecologic ultrasound and claimed that there was little standardization in training.7
One proposed solution is to introduce an accreditation training process to standard ob/gyn training. When facilitated feedback from a board-certified ob/gyn sonography expert is included, the quality of sonographic examinations performed by ob/gyn residents reportedly improves markedly.8
Others have proposed simulation-based training, wherein residents train on a virtual-reality transvaginal simulator until they attain an expert performance level and progress to training using a pelvic mannequin.9 In a randomized study of new ob/gyn residents with no prior ultrasound experience, researchers found that a rigorous simulation-based ultrasound training program led to a substantial improvement in clinical performance (as graded by the Objective Structured Assessment of Ultrasound Skills [OSAUS] scale) that was sustained for months during clinical training.9
In fact, a poster presented at this year’s annual meeting of the American College of Obstetricians and Gynecologists demonstrated that when medical students were tasked with teaching inexperienced rural healthcare workers to use the Rural Obstetrical Ultrasound Triage Exam-a diagnostic algorithm using portable ultrasound in rural areas to triage patients for future risk of maternal or fetal complications-there was a significant improvement in the quality of the healthcare workers’ practical sonographic skills.10
Technological advances are increasing at an exponential rate, and as the tools improve, so do their clinical and research applications. Pregnancies can be identified earlier, complications can be detected sooner and more accurately, and some data are so robust that we don’t have the tools to know how to interpret them.
For example, a recently published study found that rates of mouth movement and facial self-touch differ significantly between the fetuses of smokers and those of nonsmokers.11 These authors openly admit that interpretation and extrapolation of these data are difficult and that further research is needed to help understand why and how this all comes together.
From a technological standpoint, ultrasound is the wave of the future.
1. Donald I, MacVicar J, Brown TG. Investigation of abdominal masses by pulsed ultrasound. Lancet. 1958;1:1188–1195.
2. Donald I. Clinical applications of ultrasonic techniques in obstetrical and gynaecological diagnosis. Br J Obstet Gynaecol. 1962;69:1036.
3. Donald I, Abdulla U. Placentography by sonar. J Obstet Gynaecol Br Commonw. 1968;75:993–1006.
4. Voluson E10 OB/GYN Ultrasound with World's First Curved Matrix Electronic 4D Probe. http://www.medgadget.com/2014/09/voluson-e10-obgyn-ultrasound-with-worlds-first-curved-matrix-electronic-4d-probe.html. Accessed August 21, 2015.
5. The US Food and Drug Administration. Avoid Fetal "Keepsake" Images, Heartbeat Monitors http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm095508.htm. Accessed August 21, 2015.
6. The Wall Street Journal. Pregnant women get more ultrasounds, without clear medical need. http://www.wsj.com/articles/pregnant-women-get-more-ultrasounds-without-clear-medical-need-1437141219. Accessed August 21, 2015.
7. Green J, Kahan M, Wong S. Obstetric and gynecologic resident ultrasound education project: Is the current level of gynecologic ultrasound training in Canada meeting the needs of residents and faculty? J Ultrasound Med. 2015 Aug 7. pii: 15.14.10067. [Epub ahead of print]
8. Popowski T, Huchon C, Fathallah K, Falissard B, Dumont A, Fauconnier A. Impact of accreditation training for residents on sonographic quality in gynecologic emergencies. J Ultrasound Med. 2015;34(5):829-835.
9. Tolsgaard MG, Ringsted C, Dreisler E, et al. Sustained effect of simulation-based ultrasound training on clinical performance: a randomized trial. Ultrasound Obstet Gynecol. 2015. doi: 10.1002/uog.14780. [Epub ahead of print]
10. Sanchez O, Baker J, Vaughan J, et al. The Rural Obstetrical Ultrasound Triage Exam (ROUTE): Teaching Health Care Workers in International Settings .
11. Reissland N, Francis B, Kumarendran K, Mason J. Ultrasound observations of subtle movements: a pilot study comparing foetuses of smoking and nonsmoking mothers. Acta Paediatr. 2015;104(6):596-603.