10-17 ultrasounds during low-risk pregnancies are becoming the norm, even as research shows that fetal ultrasound alters the brain.
Her pregnancy was really hard. Michelle, 26 at the time, was nauseous, exhausted, and angry.
“I felt so awful,” the mom of two, who requested that Reset not use her last name, remembers when I reach her by phone at her home in Missoula, Montana. “I kept saying to myself, ‘I don’t want this baby anymore, I don’t want this thing in my body.’”
But besides the nausea and vomiting, Michelle had a healthy, low-risk, and medically uneventful pregnancy.
She also had an ultrasound at every doctor’s visit, seeing the baby in his watery world in grainy black and white ten times during pregnancy.
Having a scan at every visit, including first trimester trans-vaginal ultrasounds, has become increasingly common in low-risk pregnancies.
But in 2014 the American College of Radiology cautioned that fetal ultrasound “should be performed only when there is a valid medical reason and the lowest possible ultrasonic exposure settings should be used.” Furthermore, Cochrane review researchers, in a paper included in the World Health Organization’s Reproductive Health Library, say there is little evidence that routine early ultrasounds improve fetal outcomes.
At the same time, recent research that has gotten little attention in the media — or from practicing obstetricians — suggests that ultrasound exposure may be harmful for the developing fetus.
How so? Eitan Kimmel, Ph.D., a biomedical engineering professor at the Technion – Israel Institute of Technology and one of a team of researchers exploring ultrasound, explains that ultrasound exposure changes human tissue by creating small air pockets — bubbles — inside cell membranes.
Imagine the cells inside the body are a like a pita, Kimmel tells me when we talk by Skype, illustrating the phenomenon by cupping his two hands together to form a round ball with air inside it. As the ultrasound penetrates the fetal tissue, small pockets of air slip into the cell membranes and distort them periodically. Kimmel flattens his hands together and then puffs them out again. This “intramembrane cavitation” has the potential to change cells in the human body, particularly cells that are not densely packed together in other tissue.
“A membrane which is around a cell, which is inside dense tissue, will not inflate or deflate as much as a membrane that is near a free surface where it is easier to push away the surrounding liquid as the membrane inflates and deflates,” Kimmel explains.
Kimmel’s biggest concern? That the cells in the ventricles of the developing fetal brain, especially in the first trimester when the fetus is the most vulnerable, can be negatively affected by ultrasound.
Low-risk women get an average of 5.2 scans per pregnancy, up 92 percent from 2004, according to one analysis compiled for the Wall Street Journal. Despite its tremendous popularity, Kimmel is not the first scientist to question the safety of fetal imaging during pregnancy.
Doing blind computer analyses comparing typical and atypical human brains, an international team of researchers, including Manuel Casanova, M.D., professor in the Department of Pediatrics at the Greenville Health System who holds an endowed chair in Childhood Neurotherapeutics at the University of South Carolina, demonstrated that the brains of people with autism have an abnormal number of micro cellular structures (called “minicolumns”) compared to neurotypical children. Casanova hypothesizes that the brain anomalies can be triggered by some ill-timed environmental factor, like ultrasound, which causes fetal brain cells to divide and migrate at inappropriate times.
Kimmel’s research also dovetails with a 2008 study published in PLOS ONE where researchers at Arizona State University successfully used ultrasound to excite nerve cells in the brains of rats.
While these kind of studies have exciting ramifications for the future therapeutic use of ultrasound to heal damaged neurons or offset adult-onset brain disorders like Alzheimer’s or depression, they have worrisome implications for how ultrasound could be harming the developing human brain.
A new report from California, which has the country’s most comprehensive and reliable tracking system for autism and developmental disabilities, details that there has been a 25-fold increase in autism from 30 years ago.
According to the CDC, 1 in 68 children in America has an autism spectrum disorder and a whopping 1 in 6 children has a developmental disability, ranging from speech and language delays to severe developmental disabilities, including autism.
Could some of the escalating number of brain anomalies among America’s children be triggered by prenatal ultrasound?
“Eitan Kimmel’s data show that ultrasounds have the potential to cause alterations in brain development,” says Jill Ryer-Powder, Ph.D., a toxicologist based in Orange County, California and director of Environmental Health Decisions, who is familiar with Kimmel’s research but was not involved in the study.
“…I’m not a medical doctor,” Ryer-Power says, “[but] I can say that I personally would limit my exposure during pregnancy to ultrasounds that are actually medically critical.”
Responsible practitioners agree that the astonishing rise in brain dysfunction, including autism, should give every obstetrician pause before doing any ultrasounds or any other potentially harmful intervention during pregnancy.
“What if the effect is cumulative?” Kimmel asks. “If you make the membranes looser on the first exposure, then more so on the second exposure? What if you do not know the safety parameters and you are using too much? It’s like X-rays. You have to be very careful.”
“The message needs to be gotten out,” Phillip J. Bendick, Ph.D., an ultrasound scientist and editor of the Journal of Diagnostic Medical Sonography, recently told a reporter for The Wall Street Journal. “The public needs to be made aware that if you’re pregnant, you don’t drink alcohol, you don’t smoke and you don’t need to have an ultrasound at every doctor’s visit.”
Why so many scans?
Aviva Romm, a Yale-trained M.D. based in West Stockbridge, Massachusetts, says that it is often doctors who push ultrasounds on pregnant women, and often for the wrong reasons.
“There are OBs who purchase ultrasound machines because putting an ultrasound on a mom allows you to code for a higher billing so you get more money for that visit,” Romm explains. Though this allows some doctors to spend more time with their patients, Romm is concerned that money — not medical necessity — is the motivating factor for so many pregnancy scans. “It’s a way to pad the practice because OBs have such high malpractice overhead and they need to cover their costs.”
“It’s not great technology,” insists Jessica Goldstein, M.D., a family medicine physician in Salinas, California, who counsels women that they do not have to have any ultrasounds during pregnancy, but offers them a 19-week ultrasound (called an “anatomy scan”) to check if the baby is growing normally, if they want it. “In general it misses a lot of abnormalities. It also picks up abnormalities that are not real abnormalities.”
Jen Simon got 30 ultrasounds during her first pregnancy in New York City. Her doctors told her they wanted to monitor the pregnancy closely because they believed the baby was growth restricted. Simon is only 5’3”. Her husband barely clears 5’6”. Despite their small stature, the doctors were concerned. During her second trimester Simon went twice a week for scans.
“I was told I was lucky I wasn’t getting three a week,” says the 38-year-old mom of two who now lives in South Orange, New Jersey. She suffered from severe postpartum depression after her son was born, which she attributes partly to the anxiety she experienced during the pregnancy, which was fueled by so much monitoring.
“It wasn’t reassuring,” Simon says bluntly. “I don’t know if they were just overzealous or if there really could have been a problem.”
Simon’s son, Noah, is almost six years old. He taught himself to read when he was three, is obsessed with outer space, and likes to read bedtime books about the solar system. Simon was relieved to have far fewer ultrasounds with her second son, who just turned two. “I’m glad I didn’t have to do it a second time,” she says. “He didn’t have the same growth issue.”
Michelle’s son was a happy, energetic child until he was five. But a year ago last August, three weeks after he got a DTaP vaccine, he spiked a high fever and broke out in a whole body rash. So ill he missed three months of school and was sleeping 22 hours a day, he was diagnosed with mono. He has been suffering from lethargy, leg pains, and chronic ear infections ever since. Every illness starts with a headache, his mother says. Doctors now believe he has an autoimmune disorder. No one has thought to connect his illness to prenatal ultrasounds.
“The jury is not one hundred percent in or out about whether ultrasound is really safe,” argues Dr. Aviva Romm. “Any time the jury is out, I recommend the precautionary principle. The way I sum this up to my patients is: When in doubt leave it out.”
Jennifer Margulis, Ph.D., is an award-winning investigative journalist, a Fulbright grantee, and the author of Your Baby, Your Way: Taking Charge of Your Pregnancy, Childbirth, and Parenting Decisions for a Happier, Healthier Family (Scribner 2015).