When my wife and I were expecting our son, we told friends and family that we planned to skip our first trimester ultrasound. They looked at us in horror—as though we had, all at once, rejected vaccines, denied climate change, and declared the Earth flat.
Our doctors and nurses were no better. Nobody declines an ultrasound, one nurse informed us as we sat, resolute, in a Westchester medical office. They’re simple and painless! You can frame the chalky images and show off your insectoid blob of a legacy! Second trimester ultrasounds, she added, can catch defects that modern medicine can sometimes fix. One well-timed ultrasound could save a life.
She was right, of course. “But,” I asked. “Is there any medical necessity for the first trimester ultrasound? Is there anything you expect to find in this ultrasound that’ll change how we proceed?” The answer was silence and—after our doctor rattled off ultrasound safety statistics in the same bored tone that clinicians reserve for swatting away whatever you read on WebMD diagnoses—capitulation.
“Then we’d like to decline.”
Nobody declines an ultrasound, but maybe more people should. While medical organizations and insurance companies agree that most low-risk women need only one ultrasound per pregnancy (the second trimester “anatomy scan”), studies suggest that the average American mother-to-be gets more than four before her due date and that almost all women sit for first and third trimester ultrasounds. That’s not even counting the women who pay for prenatal family photos, taken by amateurs in malls or bodegas.
Dads may be amused. Doctors, not so much. “Exposing the fetus to ultrasound energy with no anticipation of medical benefit is not justified,” according to a 2016 practice bulletin from the American Board of Obstetrics and Gynecology. “Although there is no reliable evidence of physical harm to human fetuses from diagnostic ultrasound imaging using current technology, casual use of ultrasonography, especially during pregnancy, should be avoided.” So ABOG gets its knickers in a twist because ultrasounds are powerful diagnostic tools, not toys. But, even so, what’s the harm?
Clinically speaking, not a whole lot. Extensive studies—one paper tracked 149 sets of siblings (one of whom, in each case, had been exposed to ultrasound) for six years and another one involved a randomized, controlled trial involving 3,000 parents—found no adverse effects from medically-administered ultrasounds. We don’t have many solid studies on outcomes from ultrasounds taken by non-medical professionals, but also no reason to assume that would be significantly different. Even the spoilsport FDA seems only halfheartedly committed to poo-pooing the practice. “Ultrasound can heat tissues slightly, and in some cases, it can also produce very small bubbles (cavitation) in some tissues,” Shahram Vaezy wrote in 2014 FDA Consumer Update. Vaezy also acknowledged, however, that “there is a lack of evidence of any harm due to ultrasound imaging.”
But that doesn’t mean we should be zapping baby bumps willy nilly. Ultrasonography, like all diagnostic medicine, should be evidence-based and deliberate. Women with certain types of high-risk pregnancies should get multiple ultrasounds. Everyone should get the second trimester ultrasound, which is medically necessary and can save lives. And nobody with a low-risk pregnancy should be getting a first trimester ultrasound, unless there’s a specific reason for the procedure.
One reason to shy away from unnecessary ultrasounds is that every medical procedure carries some risk and, without any hope for gain, taking that risk is irresponsible. Tylenol, for example, is incredibly safe and, when taken as directed, is a fine way to stave off a headache. At the same time, the household drug can cause liver failure. No doctor would tell you Tylenol is fatal, because it isn’t. At the same time, no doctor would suggest you take Tylenol for no reason because there’s only a potential downside (and no potential upside) to taking Tylenol for kicks.
Ultrasounds, much like Tylenol, are nothing to be concerned about generally. But that doesn’t mean there isn’t a distant chance of harm. At least one small study found that ultrasounds may contribute to or worsen birth defects, for instance. Alone, these statistics are nothing to worry about. But when contemplating your fourth ultrasound during a low-risk pregnancy, it makes sense to consider whether or not the math plays out in your favor. If not, why risk it?
Why, then, do so many doctors aggressively push for extra ultrasounds in low-risk pregnancies?
One reason is that doctors need to protect themselves. Patients often pressure physicians to run unnecessary tests and, if something goes wrong, sue them for not testing enough. “We live in a medical climate where doctors are constantly afraid of getting sued,” Dr. Jeffrey A. Kuller of Duke University Medical Center told What To Expect in 2015. “Scans give patients and doctors assurances that things are good, and fear of litigation pushes doctors to do more testing in everything, including ultrasounds. I think the average patient is probably getting scanned more than they need to be.”
This obsession with “just in case” healthcare contributes to demand for unnecessary ultrasounds, as well as demand for thousands of unnecessary x-rays, antibiotic prescriptions, and other forms of wasteful medical spending every year. It’s also one of the main reasons our healthcare system is broken. By some estimates, 14 percent of the one trillion dollars we waste in US healthcare each year comes down to precisely this sort of “clinical waste”. The fact that most women are encouraged to have four ultrasounds per pregnancy is a perfect example of non-medical medicine. It’s not worth it.
So we sat in that Westchester office, the hot glare of our scandalized nurse burning holes in the backs of our heads, and asked our doctor to explain why we really needed a first trimester ultrasound. Were we high-risk? No. Was the doctor looking for anything in particular? Not really. Were we planning to sue? Of course not. We were sitting in a room full of people who all wanted the same positive outcome, but we were behaving like enemies. I’m not afraid of ultrasonic beams, but I also don’t want my doctors making decisions because they’re scared I’m going to sue them. And I certainly don’t want to expose my child to a medical intervention that he doesn’t need, because everything carries some risk.
We decided to wait another trimester. Maybe you should too.
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