Study Raises Doubts About Induced Labor as a Cause of ASD

In The Politics of Autism, I discuss various ideas about what causes the condition.  Sometimes, research identifies potential risk factors, but sometimes it tends to disconfirm them.

A release from the Harvard T.H. Chan School of Public Health:

Induction of labor appears not to be associated with increased risk of autism spectrum disorders in children in a large new study led by Harvard T.H. Chan School of Public Health. The new finding suggests that concern about autism risk should not factor into clinical decisions about whether or not to induce labor.

The study will be published online July 25, 2016 in JAMA Pediatrics.

Autism spectrum disorders (ASD) —a group of permanent developmental disabilities characterized by impairments in social interaction, language development, and repetitive behaviors—are estimated to affect roughly 1 in 90 children in the U.S.

Labor induction is recommended when labor doesn’t progress on its own and there’s concern that waiting for it to start could endanger the health of the baby or mother. Methods to induce labor include rupturing of membranes, mechanical or pharmacological ripening of the cervix, and administration of oxytocin, either used alone or in combination.

In 2013, a large study in North Carolina found an association between induction of labor and risk of autism in offspring. The report gained widespread media attention, and although both the paper’s authors and other experts cautioned that the association may not be causal, obstetricians began reporting that some of their patients were expressing concern about or opposition to being induced. The Harvard Chan School researchers decided to further explore whether induction of labor truly causes increased risk of neuropsychiatric disorders, in order to help in weighing the risks and benefits of this common therapeutic intervention.

“When we used close relatives, such as siblings or cousins, as the comparison group, we found no association between labor induction and autism risk,” said Anna Sara Oberg, research fellow in the Department of Epidemiology at Harvard Chan School and lead author of the study. “Many of the factors that could lead to both induction of labor and autism are completely or partially shared by siblings—such as maternal characteristics or socioeconomic or genetic factors. Finding no association when comparing siblings suggests that previously observed associations could have been due to some of these familial factors—not the result of induction.”

Working with colleagues from Sweden’s Karolinska Institutet and Karolinska University Hospital, Harvard Medical School, andIndiana University, the Harvard Chan School researchers studied all live births in Sweden from 1992–2005. They followed over 1 million births through 2013, looking for any neuropsychiatric diagnoses and identifying all siblings and maternal first cousins. They also incorporated several measures of the mothers’ health in their analysis.

Nearly 2% of babies in the study population were diagnosed with autism during the follow-up period, the researchers found. Overall, 11% of the deliveries had involved induction of labor, often occurring in conjunction with pregnancy complications such as gestational diabetes, gestational hypertension, and preeclampsia; 23% of the induced pregnancies were post-term.

In their initial comparison of individuals who weren’t related to each other, the researchers found an association between labor induction and ASD risk, similar to that previously reported. But when they compared “induction-discordant” siblings (children born to the same mother—in one, labor was induced, in the other, it wasn’t), they no longer saw an association.

“Overall, these findings should provide reassurance to women who are about to give birth, that having their labor induced will not increase their child’s risk of developing autism spectrum disorders,” said Brian Bateman, anesthesiologist and associate professor of anesthesia at Massachusetts General Hospital and Brigham and Women’s Hospital, Harvard Medical School, and senior author of the study.

“It is important to note that the findings pertain to the risks associated with labor induction per se, and not the specific method or medication used in the process, including oxytocin,” said Oberg.

Sonia Hernández-Díaz, professor of epidemiology at Harvard Chan School, was a co-author of the study. Funding for the study came from grants 2012-34 (International Postdoctoral grant) and 340-2013-5867 (Swedish Initiative for Research on Microdata in the Social and Medical Sciences [SIMSAM]) from the Swedish Research Council and grants K08HD075831 and R01HD061817 from theNational Institutes of Health Eunice Kennedy Shriver National Institute of Child Health & Human Development.
“Association of Labor Induction With Offspring Risk of Autism Spectrum Disorders,” Anna Sara Oberg, Brian M. D’Onofrio, Martin E. Rickert, Sonia Hernandez-Diaz, Jeffrey L. Ecker, Catarina Almqvist, Henrik Larsson, Paul Lichtenstein, and Brian T. Bateman, JAMA Pediatrics, online July 25, 2016, doi: 10.1001/jamapediatrics.2016.0965
Visit the Harvard Chan School website for the latest news, press releases, and multimedia offerings.

For more information:
Marge Dwyer
617.432.8416
mhdwyer@hsph.harvard.edu
photo: iStockphoto.com

Treatments

NPR reports on oxytocin:

But so far there are only a few small studies, and none with young children. Sue Carter, a biologist at the Brain-Body Center at the University of Illinois at Chicago, says that's not much to go on.

"If I had an autistic child, I would not try this because I wouldn't want my child to be one who we later discovered had been harmed in some way," she says.

Oxytocin affects the part of the nervous system that controls functions like heart rate, breathing and digestion. Prescription versions carry warnings about side effects, including bleeding and seizures.

Carter says that's just from short-term treatment with the hormone.

"The big problem here is that there isn't any research to speak of at all on the long-term effects of oxytocin, the effects of repeated treatments, at least in children," she says.

Carter says it's possible that long-term treatment could cause a child's body to produce less oxytocin of its own or become less responsive to the hormone.

NPR reports on chelation, quoting Barbara Moore of the lead clinic at Mt. Washington Pediatric Hospital in Baltimore:

Recently, a new challenge has cropped up for Moore and her staff — chelation kits for sale on the Internet. These products — which run the gamut from clay baths to pills to test kits — claim to let consumers cure autism or Alzheimer's or hardening of the arteries without professional medical help.

One website claimed its chelation product corrects neurological damage and gets rid of mercury. Some autism advocates say mercury causes autism, but there is no scientific proof of that. Experts say chelation is not an effective autism treatment.

Moore says the products aren't safe.

"I don't recommend the oral chelation that you can get over the Internet or over the counter. We don't know what the safe level is of administering to a child or to anybody else, really," she says.

These products haven't been properly tested for any diseases other than heavy metal poisoning. In fact, the National Institutes of Health halted a study of chelation as an autism treatment, citing too much patient risk. But the NIH is studying chelation for hardening of the arteries. Results are expected to be announced in 2012.

Recently the Food and Drug Administration sent warning letters to eight companies that were selling illegal chelation therapies. FDA labeling compliance chief Michael Levy says the agency is cracking down.

"We are very concerned that the marketers of these products are preying on the most vulnerable of consumers," he says.

He's talking about consumers like Sherry Oliver who have very sick kids without many treatment options. The FDA is concerned that people will put their health at risk by using the therapies and delay seeking appropriate medical treatment.

PsychCentral reports on ecstasy:

Some scientists believe that the drug MDMA (ecstasy), which is known to increase feelings of social connection and empathy, may have psychotherapeutic benefits for those with disorders often associated with a lack of feeling connected to others, such as in schizophrenia, autism, or antisocial personality disorder.

Up until now, scientists have had a hard time objectively measuring the effects of this drug, and there has been very little research in humans. Researchers from the University of Chicago, who conducted research on healthy volunteers, have reported their new findings in the current issue of Biological Psychiatry.

“We found that MDMA produced friendliness, playfulness, and loving feelings, even when it was administered to people in a laboratory with little social contact. We also found that MDMA reduced volunteers’ capacity to recognize facial expressions of fear in other people, an effect that may be involved in the increased sociability said to be produced by MDMA,” said author Dr. Gillinder Bedi.

A backgrounder from the National Institute on Drug Abuse suggests that extreme caution is necessary:

Research in animals indicates that MDMA can be harmful to the brain—one study in nonhuman primates showed that exposure to MDMA for only 4 days caused damage to serotonin nerve terminals that was still evident 6 to 7 years later.¹ Although similar neurotoxicity has not been shown definitively in humans, the wealth of animal research indicating MDMA’s damaging properties strongly suggests that MDMA is not a safe drug for human consumption.

For some people, MDMA can be addictive.² A survey of young adult and adolescent MDMA users found that 43 percent of those who reported ecstasy use met the accepted diagnostic criteria for dependence, as evidenced by continued use despite knowledge of physical or psychological harm, withdrawal effects, and tolerance (or diminished response).³ These results are consistent with those from similar studies in other countries that suggest a high rate of MDMA dependence among users.⁴ MDMA abstinence-associated withdrawal symptoms include fatigue, loss of appetite, depressed feelings, and trouble concentrating.²

MDMA can also be dangerous to overall health and, on rare occasions, lethal. MDMA can have many of the same physical effects as other stimulants, such as cocaine and amphetamines. These include increases in heart rate and blood pressure—which present risks of particular concern for people with circulatory problems or heart disease—and other symptoms such as muscle tension, involuntary teeth clenching, nausea, blurred vision, faintness, and chills or sweating.

Bad Editing at Newsweek

A Newsweek article about oxytocin is titled "The ‘Bonding Hormone’ That Might Cure Autism." The title is irresponsible. Although the drug may or may not be a useful treatment, nobody has found a cure. The article also has a line referring to "`high-functioning autism' (a.k.a. Asperger syndrome)." Many people at the high-functioning end of the spectrum do indeed have Asperger, but many others do not. It is misleading to equate Asperger and HFA.