Why Are Autism Rates Steadily Rising?
Stefania Sterling was just 21 when she had her son, Charlie. She was young and healthy, with no genetic issues apparent in either her or her husband's family, so she expected Charlie to be typical.
"It is surprising that the prevalence of a significant disorder like autism has risen so consistently over a relatively brief period."
It wasn't until she went to a Mommy and Me music class when he was one, and she saw all the other one-year-olds walking, that she realized how different her son was. He could barely crawl, didn't speak, and made no eye contact. By the time he was three, he was diagnosed as being on the lower functioning end of the autism spectrum.
She isn't sure why it happened – and researchers, too, are still trying to understand the basis of the complex condition. Studies suggest that genes can act together with influences from the environment to affect development in ways that lead to Autism Spectrum Disorder (ASD). But rates of ASD are rising dramatically, making the need to figure out why it's happening all the more urgent.
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Indeed, the CDC's latest autism report, released last week, which uses 2016 data, found that the prevalence of ASD in four-year-old children was one in 64 children, or 15.6 affected children per 1,000. That's more than the 14.1 rate they found in 2014, for the 11 states included in the study. New Jersey, as in years past, was the highest, with 25.3 per 1,000, compared to Missouri, which had just 8.8 per 1,000.
The rate for eight-year-olds had risen as well. Researchers found the ASD prevalence nationwide was 18.5 per 1,000, or one in 54, about 10 percent higher than the 16.8 rate found in 2014. New Jersey, again, was the highest, at one in 32 kids, compared to Colorado, which had the lowest rate, at one in 76 kids. For New Jersey, that's a 175 percent rise from the baseline number taken in 2000, when the state had just one in 101 kids.
"It is surprising that the prevalence of a significant disorder like autism has risen so consistently over a relatively brief period," said Walter Zahorodny, an associate professor of pediatrics at Rutgers New Jersey Medical School, who was involved in collecting the data.
The study echoed the findings of a surprising 2011 study in South Korea that found 1 in every 38 students had ASD. That was the the first comprehensive study of autism prevalence using a total population sample: A team of investigators from the U.S., South Korea, and Canada looked at 55,000 children ages 7 to 12 living in a community in South Korea and found that 2.64 percent of them had some level of autism.
Searching for Answers
Scientists can't put their finger on why rates are rising. Some say it's better diagnosis. That is, it's not that more people have autism. It's that we're better at detecting it. Others attribute it to changes in the diagnostic criteria. Specifically, the May 2013 update of the Diagnostic and Statistical Manual of Mental Disorders-5 -- the standard classification of mental disorders -- removed the communication deficit from the autism definition, which made more children fall under that category. Cynical observers believe physicians and therapists are handing out the diagnosis more freely to allow access to services available only to children with autism, but that are also effective for other children.
Alycia Halladay, chief science officer for the Autism Science Foundation in New York, said she wishes there were just one answer, but there's not. While she believes the rising ASD numbers are due in part to factors like better diagnosis and a change in the definition, she does not believe that accounts for the entire rise in prevalence. As for the high numbers in New Jersey, she said the state has always had a higher prevalence of autism compared to other states. It is also one of the few states that does a good job at recording cases of autism in its educational records, meaning that children in New Jersey are more likely to be counted compared to kids in other states.
"Not every state is as good as New Jersey," she said. "That accounts for some of the difference compared to elsewhere, but we don't know if it's all of the difference in prevalence, or most of it, or what."
"What we do know is that vaccinations do not cause autism."
There is simply no defined proven reason for these increases, said Scott Badesch, outgoing president and CEO of the Autism Society of America.
"There are suggestions that it is based on better diagnosis, but there are also suggestions that the incidence of autism is in fact increasing due to reasons that have yet been determined," he said, adding, "What we do know is that vaccinations do not cause autism."
Zahorodny, the pediatrics professor, believes something is going on beyond better detection or evolving definitions.
"Changes in awareness and shifts in how children are identified or diagnosed are relevant, but they only take you so far in accounting for an increase of this magnitude," he said. "We don't know what is driving the surge in autism recorded by the ADDM Network and others."
He suggested that the increase in prevalence could be due to non-genetic environmental triggers or risk factors we do not yet know about, citing possibilities including parental age, prematurity, low birth rate, multiplicity, breech presentation, or C-section delivery. It may not be one, but rather several factors combined, he said.
"Increases in ASD prevalence have affected the whole population, so the triggers or risks must be very widely dispersed across all strata," he added.
There are studies that find new risk factors for ASD almost on a daily basis, said Idan Menashe, assistant professor in the Department of Health at Ben-Gurion University of the Negev, the fastest growing research university in Israel.
"There are plenty of studies that find new genetic variants (and new genes)," he said. In addition, various prenatal and perinatal risk factors are associated with a risk of ASD. He cited a study his university conducted last year on the relationship between C-section births and ASD, which found that exposure to general anesthesia may explain the association.
Whatever the cause, health practitioners are seeing the consequences in real time.
"People say rates are higher because of the changes in the diagnostic criteria," said Dr. Roseann Capanna-Hodge, a psychologist in Ridgefield, CT. "And they say it's easier for children to get identified. I say that's not the truth and that I've been doing this for 30 years, and that even 10 years ago, I did not see the level of autism that I do see today."
Sure, we're better at detecting autism, she added, but the detection improvements have largely occurred at the low- to mid- level part of the spectrum. The higher rates of autism are occurring at the more severe end, in her experience.
A Polarizing Theory
Among the more controversial risk factors scientists are exploring is the role environmental toxins may play in the development of autism. Some scientists, doctors and mental health experts suspect that toxins like heavy metals, pesticides, chemicals, or pollution may interrupt the way genes are expressed or the way endocrine systems function, manifesting in symptoms of autism. But others firmly resist such claims, at least until more evidence comes forth. To date, studies have been mixed and many have been more associative than causative.
"Today, scientists are still trying to figure out whether there are other environmental changes that can explain this rise, but studies of this question didn't provide any conclusive answer," said Menashe, who also serves as the scientific director of the National Autism Research Center at BGU.
"It's not everything that makes Charlie. He's just like any other kid."
That inconclusiveness has not dissuaded some doctors from taking the perspective that toxins do play a role. "Autism rates are rising because there is a mismatch between our genes and our environment," said Julia Getzelman, a pediatrician in San Francisco. "The majority of our evolution didn't include the kinds of toxic hits we are experiencing. The planet has changed drastically in just the last 75 years –- it has become more and more polluted with tens of thousands of unregulated chemicals being used by industry that are having effects on our most vulnerable."
She cites BPA, an industrial chemical that has been used since the 1960s to make certain plastics and resins. A large body of research, she says, has shown its impact on human health and the endocrine system. BPA binds to our own hormone receptors, so it may negatively impact the thyroid and brain. A study in 2015 was the first to identify a link between BPA and some children with autism, but the relationship was associative, not causative. Meanwhile, the Food and Drug Administration maintains that BPA is safe at the current levels occurring in food, based on its ongoing review of the available scientific evidence.
Michael Mooney, President of St. Louis-based Delta Genesis, a non-profit organization that treats children struggling with neurodevelopmental delays like autism, suspects a strong role for epigenetics, which refers to changes in how genes are expressed as a result of environmental influences, lifestyle behaviors, age, or disease states.
He believes some children are genetically predisposed to the disorder, and some unknown influence or combination of influences pushes them over the edge, triggering epigenetic changes that result in symptoms of autism.
For Stefania Sterling, it doesn't really matter how or why she had an autistic child. That's only one part of Charlie.
"It's not everything that makes Charlie," she said. "He's just like any other kid. He comes with happy moments. He comes with sad moments. Just like my other three kids."
[Editor's Note: This is the final video of a five-part series titled "The Future Is Now: The Revolutionary Power of Stem Cell Research." Produced in partnership with the Regenerative Medicine Foundation, and filmed at the annual 2019 World Stem Cell Summit, this series illustrates how stem cell research will profoundly impact human life.]
Kira Peikoff was the editor-in-chief of Leaps.org from 2017 to 2021. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and two young sons. Follow her on Twitter @KiraPeikoff.
The Troubling Reason I Obsessively Researched My Pregnancy
At the end of my second trimester of pregnancy, I answered a call from an unknown number.
To be pregnant is to exist on a never-ending receiving line of advice, whether we want it or not.
"I know your due date is approaching," said a stranger at the other end of the line, completely freaking me out. She identified herself as being from Natera, a company that my doctor had used for genetic testing I had consented to months ago.
"Excuse me?" I said.
"Have you considered cord-blood banking?" she said.
"No, I'm not doing that," I said. I had read enough about cord-blood banking, the process of saving stem cell-containing blood from your baby's umbilical cord, to understand that my family was in the vast majority of those that would with extremely high likelihood derive no medical benefit from it. Of course, in the societally sanctioned spending spree that accompanies new parenthood, plenty of companies are happy to charge anyone hundreds if not thousands of dollars plus annual storage fees to collect and manage your cord blood.
"Why not? Have you considered all the bene—"
"I'm not doing it and I don't want to explain my decision," I said before hanging up. I would later learn I neglected to check a miniscule box on my testing consent forms at the doctor to opt out of solicitations. Still, I was angry that I was being telemarketed unnecessary and costly medical services by someone who had been trained to immediately call my judgment into question. I was annoyed that my doctor's office would allow such intrusions at all. When I asked my OB about it at my next visit, she told me there's no way Natera would have gotten my information from them. Apparently even she didn't realize what was on those forms.
The incident with Natera did nothing to heighten my trust of the medical establishment during my pregnancy. I was hardly alone. Almost every mom I knew had expressed a similar sentiment.
"I don't trust doctors," read the text of a loved one when I told her I would probably get an epidural after my doctor recommended getting one because, she said, it can help relax the pelvic muscles during labor. But this friend, a highly educated woman who had had done her research and had two unmedicated births, believed firmly otherwise. "Look it up," she said. Thus commenced more of the furious Googling I found myself doing multiple times a day since deciding I wanted to become pregnant.
To be pregnant is to exist on a never-ending receiving line of advice, whether we want it or not. Information presents to us from Google's never-out-of-reach search bar, friends and family eager to use our pregnancies as an excuse to recall their own, and the doctor's office, where the wisdom of medical professionals neatly comingles with brochures and free samples from myriad companies that would really, really like our business as new moms. Separating the "good" advice from the rest is a Herculean task that many pregnant women manage only with vigorous fact-finding missions of their own.
The medical community in America is poorly equipped to help women navigate the enormous pressures that come with birth and transitioning to motherhood.
Doing my research during pregnancy felt like a defense against the scary unknowns, overabundance of opinions, and disturbing marketing schemes that come with entering parenthood. The medical community in America is poorly equipped to help women navigate the enormous emotional and societal pressures that come with birth and transitioning to motherhood. Too much of what pregnant women experience at the doctor has to do with dated ideas about our care, mandated by tradition or a fear of being sued rather than medical necessity. These practices, like weigh-ins at every appointment or medically unnecessary C-sections (which are estimated to account, horrifically, for almost 50 percent of all C-sections performed in the U.S.), only heighten anxiety.
Meanwhile, things that might alleviate stress – like having thorough discussions about the kinds of interventions we might be asked to accept at the hospital during labor and delivery – are left to outside educators and doulas that insurance plans typically don't cover. The net effect isn't better health outcomes for mom and baby, but rather a normalized sense of distrust many American women feel toward their OBGYNs, and the burden of going to every appointment and the delivery room on the defensive. Instead of being wed to dated medical practices and tangled in America's new motherhood industrial complex, shouldn't our doctors, of all people, be our biggest advocates?
As soon as I found out I was pregnant, I devoured Expecting Better, by Emily Oster, an economist who embarked on her own fact-finding mission during her first pregnancy, predicated on the belief that the advice OBGYNs have been giving pregnant women for decades is out of date and unnecessarily restrictive. The book includes controversial stances, like that having small amounts of alcohol while pregnant is OK. (More recent research has called this view into question.) Oster writes that for the vast majority of pregnant women, it's perfectly fine to lie on your back, do sit-ups, and eat Brie — all things I was relieved to learn I wouldn't have to give up for nine months, despite the traditional advice, which my doctor also gave to me.
Oster recommends hiring a doula, based both on research and personal experience. It's a worthwhile investment for those who can afford it: according to one study, 20.4 percent of laboring women with doulas had C-sections compared with 34.2 percent of women without them. A doula can do many things for a pregnant client, including helping her write a birth plan, massaging her back in labor, and cheering her on, which is especially useful for women who plan to labor without pain medication. Use of doulas is on the rise; according to DONA International, the world's largest and oldest doula association, the number of doulas who have been certified to date is over 12,000, up from 2,000 in 2002.
But the most significant role a doula plays is that of patient advocate in the hospital. This is a profound commentary on the way the medical establishment handles childbirth, a medical event that 86 percent of women aged 40 to 44 had gone through as of 2016. Recognizing the maternal mortality crisis in the U.S., where women are far more likely to die as a result of childbirth than anywhere else in the developed world and black women are three times more likely to die in childbirth than white women, a few states now allow Medicaid to cover doulas. Can you imagine feeling the need to hire an independent non-medical care provider to help you run interference with your doctors and nurses for something like an appendectomy?
I wouldn't have been aware of all the imminent interventions during my labor if my doula hadn't told me about them. Things happen fast in the hospital and doctors and nurses may rush patients to consent before proceeding with things like breaking their water or hooking them up to an IV of Pitocin. Only because my husband and I had spent six hours in birth class — a suggestion by my doula — did I realize that I was empowered to say "no" to such procedures.
Expecting more trustworthy advice to come from my doctor than books or Google or even a doula hardly seems unreasonable.
Of course, we all feel immense pressure to become good parents, and questioning conventional medical wisdom is a natural response to that pressure. "Looking around at the world and saying, who am I as a parent? What is important to me? Who are the wise people? What do I think wisdom is? What is a good decision? If you're a certain type of introspective person, if you're really asking those questions, that's going to include like taking a second look at things that doctors, for example, say," says Koyuki Smith, a doula and birth educator.
Expecting more trustworthy advice to come from my doctor than books or Google or even a doula hardly seems unreasonable. Yet my doctor's office seemed more concerned with checking off a list of boxes rather than providing me with personalized care that might have relieved my understandable anxiety about my first birth. When I still hadn't gone into labor around the time of my due date, my doctor encouraged me to be induced because my baby appeared to be large. I declined but scheduled an induction to "hold my spot" around the 42-week mark.
When I asked what medication would be used for an induction if I had one and she said Cytotec, I told her I had read that drug could cause serious complications, but she dismissed my concerns after I told her they stemmed from a book I read on natural childbirth. The FDA's page on Cytotec isn't exactly reassuring.
The nurse who took me in triage after I went into labor a week past my due date practically scolded me for waiting to go into labor naturally instead of opting for induction sooner. My doula told her while I was struggling to speak through labor pains to get off my case about it. I hadn't even become a mom and I was already doing so many things "wrong." Because I had done my own reading, I felt confident that my choices weren't harming my baby or me.
Becoming a mom would be less daunting if the medical community found a way to help women navigate the pressures of motherhood instead of adding to them. "Our culture at large doesn't support women enough in the complicated emotions that are a part of this process," said Alexandra Saks, a reproductive psychologist and author of What No One Tells You: A Guide to Your Emotions From Pregnancy to Motherhood. "I hope that every practitioner that works with women around reproductive health prioritizes her emotions around her experience."
For many of us, that will mean doctors who help us understand the pros and cons of conventional advice, don't use their offices as marketing channels, and don't pressure women into medically unnecessary inductions. Moms should also receive more attention after delivery both in the hospital and after they get home; a single, quick postpartum visit at six weeks is not an adequate way to care for women recovering from the trauma of childbirth, nor is it an adequate way to ensure women are emotionally supported during the transition. While several people interrogated me about my mental health at the hospital and my doctor's office just before and after birth, if I had been concerned about postpartum depression, I can't imagine feeling comfortable enough in those moments to tell strangers filling out obligatory worksheets.
It also means figuring out how to talk to patients who are prone to Googling their pregnancies with gusto every single day. It would be impossible for many women to shun independent research during pregnancy altogether. But it would also be nice if our doctors didn't add to our impulse to do it.