Two recent studies in the Archives of General Psychiatry show that environmental factors play a major role in the development of autism. The findings are significant because for decades, the mainstream medical establishment has steadfastly maintained that the causes of autism are primarily genetic. However, some experts, and many parents, have known for years that the causes of autism are largely environmental.
In fact, autism is believed by many to be caused by a genetic susceptibility followed by an environmental trigger or triggers. The rate of autism has increased tenfold in the past 15 years, a rise that cannot be solely attributed to factors such as changes in diagnostic criteria.
In the first study, researchers examined 192 pairs of identical and fraternal twins from California. Each pair had at least one twin with autism. The study showed that environmental, or non-genetic factors in the womb, may significantly influence whether a child develops autism.
The study showed that when one identical twin had autism, his or her twin only had autism about two-thirds of the time, a figure lower than expected, since identical twins have the same DNA.
Meanwhile, fraternal twins in the study both had autism about one-fourth of the time, which was higher than anticipated, because fraternal twins are no more likely to have similar DNA than any other siblings, yet they share the same womb at the same time.
In a smaller study, antidepressant use by pregnant mothers during the year before giving birth, especially during the first trimester, was found to lead to an increased risk of having children with autism. Exposure to SSRIs including Prozac, Zoloft, Luvox, Celexa, and Paxil in the womb increased the risk of autism 2.2-fold.
Certain drugs used to treat depression, anxiety, and psychiatric disorders have been known for years to cause complications in pregnancy. Anti-anxiety medications such as Xanex and mood stabilizers taken during pregnancy may cause birth defects. In 2004, the Food and Drug Administration issued a warning against using the antidepressant Effexor during the late third trimester because of complications.
In 2006, an American College of Obstetricians and Gynecologists' (ACOG) press release warned that the SSRI medication Paxil be avoided during pregnancy because of potential complications. The release states that “exposure to SSRIs late in pregnancy has been associated with short-term complications in newborns including jitteriness, mild respiratory distress, excessively rapid respiration, weak cry, poor muscle tone, and admission to the neonatal intensive care unit.”
In the past, pregnant women were simply told to take pre-natal vitamins, avoid alcohol, and abstain from smoking. Educated mothers-to-be today need to be aware of the risks of environmental toxins more than ever before to ensure their fetuses are not affected by increases in pollutants that could cause autism or other problems. Mercury and other heavy metals, chemicals found in everyday products, and pesticides are just a few of the risks that have been associated with autism and other medical issues in unborn children.
Pregnant women must rely on information from doctors or government agencies that is sometimes recklessly contradictory. For example, the National Institute of Mental Health states on its website, “Research has shown that antidepressants, especially SSRIs, are safe during pregnancy.”
Two lines later, the NIMH says, “However, antidepressant medications do cross the placental barrier and may reach the fetus. Some research suggests the use of SSRIs during pregnancy is associated with miscarriage or birth defects, but other studies do not support this. Studies have also found that fetuses exposed to SSRIs during the third trimester may be born with ‘withdrawal’ symptoms such as breathing problems, jitteriness, irritability, trouble feeding, or hypoglycemia (low blood sugar).”
A year ago, Dr. Philip Landrigan of the Mount Sinai Medical Center and the National Children’s Study told Examiner.com that environmental factors contribute heavily to autism.
“Over the last decade, we’ve developed very good scientific information that links three or four classes of chemicals to brain injury in babies if the exposure occurs during pregnancy,” Landrigan said. “We’ve found that phthalates, brominated flame retardants, and certain pesticides are linked to loss of intelligence, attention deficit disorder, and Pervasive Developmental Disorder in children.”
It has been known for years that environmental toxicants are especially harmful to the developing brains of fetuses and infants. A 1993 report by the National Academies Press, "Pesticides in the Diets of Infants and Children," stated that young children are not “little adults,” and they detoxify and excrete chemicals very differently than adults. It has also been established that children with autism are more susceptible to environmental toxicants than other children.
Other information about potential environmental affects on unborn children includes:
- Earliest Exposures, a research project published by Washington Toxics Coalition in 2009, showed that Bisphenol A (BPA), phthalates, and mercury were present in each of nine pregnant women tested in a study. BPA has been identified to affect development of the brain, and phthalates and mercury have been linked to autism spectrum disorders.
- In 2004 the Environmental Protection Agency estimated that one in six infants born in the U.S. could be at risk for neurological injury from mercury, mainly from fish eaten by the mother while pregnant. Scientists believe the global rate of atmospheric mercury deposition is increasing.
- Autism advocate Lyn Redwood told Examiner.com last year, “The government has warnings out to pregnant women that you shouldn’t eat shark and tuna because of high levels of mercury so it doesn’t make sense that they would turn around and inject a pregnant woman with mercury in excess of their own federal safety guidelines. It doesn’t make any sense at all.” The government recommends pregnant women get flu shots, most of which contain the mercury preservative thimerosal.
- The CDC’s Agency for Toxic Substances and Disease Registry (ATSDR) warns, “Pregnant women and women of childbearing age should avoid exposure to lead because lead ingested by a mother can affect the unborn child.”
- A 2010 congressional investigation concluded that a 2004 CDC report knowingly downplayed the danger of lead in water in Washington, D.C. starting in 2001. The investigation found that the CDC report that was rushed to calm the fears of the public after the D.C. lead fiasco used flawed data to come to the inaccurate conclusion that lead levels in the water were safe. According to the congressional report, the CDC “made the problem go away for the agency and the politicians, but not for the parents and the children throughout the nation who will suffer lifetime consequences from this misguided document.”
The Washington Toxics Coalition has developed recommendations for mothers-to-be in Tips for a Healthy Pregnancy.
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