Scientists are using lasers to look at baby teeth for signs of autism at earlier ages. They also have advice for pregnant women.

Lead and fevers aren’t good for anyone’s body.

But babies, whose fragile systems are still developing, can be especially vulnerable to developing autism with these dangers while still in the womb.

That’s according to two recent studies.

In them, researchers also concluded that lower levels of vital minerals like manganese and zinc in babies were also linked to autism.

However, the truly groundbreaking part of one of the studies, experts said, is that lasers are now being used to analyze baby teeth to look for signs of autism.

Previously, teeth had to be ground up.

The upshot is that autism can now be found — and treated — at an earlier age.

“If we can identify higher risk children, we can follow them more closely,” Cindy Lawler, PhD, lead representative for extramural autism activities at the National Institute of Environmental Health Sciences (NIEHS), which funded the study, told Healthline. “Sometimes the child is several years old before they receive that diagnosis.”

Read more: New autism drug shows promising results »

Because baby teeth have rings, much like trees, they can be analyzed for developmental disorders.

“Now we can look at our biological hard drive,” Manish Arora, PhD, an environmental scientist and dentist at the Icahn School of Medicine at Mount Sinai in New York, and a lead researcher on the study, told Healthline. “It’s constantly recording information.”

Blood tests for autism, he added, are less useful because they can’t pinpoint when autism starts.

The researchers studied the link between autism and heavy metals by comparing teeth from 32 pairs of twins and 12 single twins.

This type of finding is nothing new, though, say experts.

More importantly, the study pinpoints risk at early ages in development, explained Thomas Frazier, PhD, chief science officer at Autism Speaks.

“Despite having this knowledge, we still do a terrible job as a society at reducing or eliminating the problem,” Frazier told Healthline.

People wanting to make an immediate impact should address lead exposure in children, he added.

This study also helps narrow down the potential gene associated with autism, explained Aisha Dickerson, PhD, a postdoctoral research fellow at the Harvard T.H. Chan School of Public Health.

“A common theory with autism says that there’s a genetic factor with an environmental trigger,” she told Healthline.

So, some kids with certain genotypes can process metal while others can’t.

In any case, you can’t alter genes, but you can alter your environment, said Dickerson.

“Our environment is constantly changing,” agreed Arora. “And our internal environment is changing, too. But fetuses and newborns are highly susceptible to environmental stressors.”

So, he added, environment is a crucial component to a baby’s health.

The connection between pollution and autism is also being studied, added Arora.

In the same study, lower levels of zinc and manganese were also linked to autism. And they’re both essential ingredients for brain development.

“Something happens that disrupts the metabolism,” he said. “But we don’t know what it is.”

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Finding the link between fevers and infection in pregnant mothers and autism has been dicier, though, said Lawler.

“A larger body of work is asking whether infection is linked to autism,” she said. “But a clear picture hasn’t emerged.”

For the other study that linked fever during pregnancy to autism, led by scientists at the Center for Infection and Immunity at Columbia University’s Mailman School of Public Health, 95,754 children were followed over 10 years.

Results showed that expectant mothers who had fevers during the second trimester of pregnancy raised the odds of autism by 40 percent.

Autism risk was more than tripled for children of women who had three or more fevers after 12 weeks of pregnancy.

“The next question that needs to be asked is whether it’s due to inflammation,” said Frazier. “If so, what specific biological processes are driving the relationship?”

Read more: Why do girls show signs of autism later than boys? »

To protect a baby during pregnancy or shortly after birth, pay attention to current lead exposure, counseled Lawler.

The biggest danger is living in older homes with lead in paint, she added. But minimizing exposure to lead during home renovation is also important.

Water usually isn’t a prime cause of lead exposure, said Dickerson. But she advises mothers to test water where they live.

As for avoiding fevers during pregnancy, she advocates staying healthy.

“Make sure to eat a healthy diet with leafy green vegetables, she added, “and wash your hands.” Vegetables should also be thoroughly washed.

And Lawler says that with folate might be helpful. But they shouldn’t be excessively used either, she added.

When in doubt, consult your physician on prenatal supplements, concluded Frazier.