Chelation should obviously be taken seriously. Few things to consider:

1) confirm heavy metals. There are about a dozen published studies showing ASD kids have more heavy metals burden than control. The best marker in my opinion to test that is not blood or hair test or urine challenge test (which can tell you different things but not very conclusive) but an indirect test called the porphyrin test. There are many published studies using this marker in context of ASD across four different countries.

2) the dangerous part of chelation is not the chelator which are well studied (DMSA or DMPS - never use EDTA) but the protocol and dosage given there is likely no acute metals toxicity (not high blood levels) and chelators also remove good metals. Taking chelators such as DMSA or DMPS in high dosage can actually create acute metals toxicity and redistribute metals which is potentially dangerous. The safest and almost therapeutic way if using such chelators is using AC protocol which is extremely low therapeutic dosage but more frequently. If this is the approach that your wife is considering, I wouldn't be worried at all but if considering traditional chelation protocols for acute cases, I would be very worried.

3) the safest approach is actually not use any chelator above but use antioxidants to help body detoxify using its own natural antioxidant (glutathione) and use natural antioxidants such as ALA (there is AC protocol for that as well). This may be the best and the safest approach.

In terms of efficacy, there are about 8 or so published studies using chelation in ASD - all of these showed efficacy / positive results but none of them were controlled studies, so cannot way whether the improvements would have happened anyway. So not the best scientific evidence. For anecdotal evidence, there is tons of stories but I wouldn't count on that.

You're right to be worried. Chelation is a serious medical procedure and should not be undertaken unless you have legitimate heavy metal poisoning. Testing protocols used by some doctors who prescribe it as an autism treatment are highly questionable. Here is some information specifically about testing methods - http://www.quackwatch.com/01QuackeryRelatedTopi...
If your child has been diagnosed with heavy metal poisoning, at the very least I would take them to their regular pediatrician to confirm the original test. Bare minimum. Chelation is nothing to be taken lightly.
I hope your ex wife will listen to your concerns. Good luck!

Hmmm. I posted an answer, and don't see it here.

I recommend you try as many "low risk" treatments as possible before chelation. Although some people do report good results from chelation, it is just as likely that the results are coming from the extra zinc, magnesium, vitamin c, and iron that you need to take to prepare for the chelation.

In addition, chelation carries risks that are not associated with other treatments. A gluten-free diet, for example, is just as likely to produce good results. If it fails, though, there is no harm done.

Also if the doc is recommending IV push of DMPS-EDTA or IV anything, then definitely do NOT do that. The one unfortunate death referenced above was due to wrong med (NaEDTA) being given via IV. Such protocols are only for acute metals toxicity (high metals burden in blood) which is NOT the case for most ASD cases and very dangerous. However if using AC protocol to simply lower heavy metals burden over time using antioxidants (or therapeutic dose of chelator) then that is worth considering and I would consider this approach safer than giving prescription meds (antibiotics, stimulants, etc.).

We have not tried it, but we have some close friends that have. Their son is nonverbal, but they track his progress in receptive language, repetitive behaviors, and sleep habits.

When they first started using chelation, they noticed a slight improvement in language skills, but they felt like it could also be due to the vitamins and minerals that he took in preparation. (Before the first dose of EDTA, they used common supplements to increase his blood levels of vitamin C, calcium, magnesium and iron. The improvement might have been due to the supplements rather than the EDTA)

After a few treatments, the improvement stopped, and then reversed. Even at low doses, they felt he was having more of the kind of symptoms they were trying to eliminate. As he got more disconnected, they began to wonder if the vitamin levels were dropping too low. When their son began to feel ill and regress, they discontinued treatment.

Although a number of parents have reported progress after chelation, the DAN doctor I spoke with said it was never his first recommendation, even for parents who are suddenly alarmed by a hair test that shows heavy metals. He believed in the procedure, he just said that he recommended other procedures first.

In particular, he recommended that each patient get tested to make sure they have enough Vitamin d, MB12, iron, fatty acids, calcium, magnesium, zinc, folic acid, b3, b6, C, and vitamin A. He does not feel anyone should try any high-risk treatment until they have tried vitamins and supplements. The complete list is pretty long.

Once you have tried the diet / vitamin / supplement route, he still does not recommend chelation unless you have tried to address brain inflammation first. To do so, he suggests, GFCF diet, Memantine, and even HBOT before turning to chelation.

Again, he feels this is the normal process parents should go through before trying chelation. If a simple and risk-free supplement works, then you never need to progress to a risky procedure. Even though chelation seems to work in some cases, it does have risks. High-quality Supplements, used properly, carry almost no risk. The GFCF diet can be expensive, but is also nearly risk-free. HBOT, and even memantine carry much lower relative risk.