Are Ultrasounds Causing Autism In Babies?
Scientists are uncovering disturbing evidence that those sneak peeks at baby could damage a developing brain.
Toward the end of my first pregnancy, a doctor ordered an “emergency” ultrasound because she believed I was measuring small. She turned to go to her next client before I could talk to her about it, muttering that she suspected “intrauterine growth retardation,”or IUGR.
My husband and I sat in the waiting room, flooded with anxiety. The scan showed the baby was fine. It wasn’t until years later when I started researching and writing about pregnancy that I learned that ultrasound scans have not been shown to be any more effective in predicting intrauterine growth restriction (doctors these days try to avoid using the word retardation) than palpation of the pregnant woman’s abdomen by an experienced clinician.
The same summer my daughter was born, Marsden Wagner, an obstetrician, scientist, and former director of Women’s and Children’s Health at the World Health Organization, wrote: “There is no justification for clinicians using routine ultrasound during pregnancy for the management of IUGR.”
Most women look forward to multiple ultrasounds because they are lulled into the assumption that this technology will catch potentially fatal abnormalities— such as a heart defect—early, so they can be fixed. When doctors tell pregnant women they will only get one or two scans, some are terribly disappointed, feeling that they won’t be able to bond as effectively with the baby or worrying that the doctor won’t know that the baby is growing normally. But one study of 15,151 pregnant women published in The New England Journal of Medicine showed that an ultrasound scan does not improve fetal outcome. The study, which was conducted by a team of six researchers over almost four years, compared pregnant women who received two scans to pregnant women who received scans only when some other medical indication suggested an ultrasound was necessary. The results showed no difference in fetal outcomes.
“This practice-based trial demonstrates that among low-risk pregnant women ultrasound screening does not improve perinatal outcome,” the authors conclude. Even when the ultrasound technology uncovered fetal abnormalities, the fetal survival or death rate was the same in both groups.
What the authors did find, however, was that routine ultrasounds led to more expensive prenatal care, adding more than $1 billion to the cost of caring for pregnant women in America each year.
Another study, of 2,834 pregnant women, published in The Lancet, showed that the babies of the randomly chosen group of 1,415 women who received five ultrasounds (as opposed to the group of 1,419 women who had only one scan at 18 weeks) were much more likely to experience intrauterine growth restriction, a scary combination of words that means the fetus is not developing normally. Ironically, intrauterine growth restriction is one of the conditions that having multiple ultrasounds is supposed to detect.
Although the American College of Obstetricians and Gynecologists recommends that obstetricians discuss the advantages and disadvantages of having an ultrasound scan with pregnant patients, ACOG does not explicitly recommend the screening. ACOG explains that ultrasound may reduce fetal mortality rates because women who discover they are carrying fetuses that are incompatible with life will often choose abortion, but ACOG also specifies that ultrasound has not been proven to be effective for reducing infant mortality in any other way.
Their policy statement continues: “Screening detects multiple gestations, congenital anomalies, and intrauterine growth restriction, but direct health benefits from having this knowledge currently are unproven. The decision ultimately rests with the physician and patient jointly.”
The authors of the definitive, exhaustive, 1,385-page textbook for obstetricians, Williams Obstetrics, take a similarly conservative stance about ultrasound and do not explicitly recommend it for low-risk pregnancies: “Sonography should be performed only with a valid medical indication,” the authors write, “and with the lowest possible exposure setting to gain necessary information.”
Yet doctors and other birth providers take great exception if low-risk pregnant women refuse to be scanned. In 2004 when Lia Joy Rundle, a mom of three from Mazomanie, Wisconsin, was just a few weeks pregnant with her second child, she changed insurance providers. The new obstetrician reviewed her paperwork. “We might be able to do a quick ultrasound today, if the machine’s available,” she said. “Then you can take a look at your baby.”
Though they were planning to have a 20-week ultrasound, Lia and her husband saw no benefit to doing an early ultrasound and felt there might be some risk. But when they declined the scan, the obstetrician insisted there was no way to get an accurate due date without it. “Look at him, he’s fine,” she scoffed, pointing at their 1-year-old son. “How many ultrasounds did you have with him?”
But as I uncovered when I was researching my book, The Business of Baby, there is mounting evidence that overexposure to sound waves—or perhaps exposure to sound waves at a critical time during fetal development—is to blame for the astronomic rise in neurological disorders among America’s children.
In 2006, Pasko Rakic, M.D., a neuroscientist at Yale University School of Medicine, found that prenatal exposure to ultrasound waves changed the way the neurons in mice distributed themselves in the brain. Rakic and his team do not fully understand what effect the brain cell migratory alteration might have on brain development and intelligence, but they noticed, rather alarmingly, that a smaller percentage of cells migrated to the upper cortical layers of the mouse brain and a larger percentage to the lower layers and white matter.
At first reluctant to publish these results because they were preliminary and might discourage pregnant women from accepting medically necessary ultrasounds (the mice studies are part of a years-long double-blind experiment that is testing the effects of ultrasound on primate brains), Rakic decided the findings were too significant to ignore and concluded that all nonmedical use of ultrasound on pregnant women should be avoided. “We should be using the same care with ultrasound as with X-rays,” Rakic cautioned.