08/19/2011 09:25 am ET Updated Oct 19, 2011

Will My Second Baby Have Autism, Too?

A new study in Pediatrics says the recurrence risk of autism in younger siblings is higher than previously thought. Hardly comforting to autism families who want a second or third child and not surprising to me, mom of three daughters with autism.

In 1999, my husband and I were considering having a third child. Mia and Gianna (4 and 3 years old at the time) had just been diagnosed with autism. Mark and I wanted answers. At the advice of our pediatrician, we sought genetic counseling. The geneticist at a top children's hospital said the chance of a third child with autism was perhaps 25 percent. He told us it was, at best, a guess. New Year's Eve 1999 arrived, we partied per the Prince song, and nine months later Bella arrived with a birth history that may have lead to her autism diagnosis.

The previously estimated risk was 3 to 10 percent. The new study shows a 26 percent recurrence for males and 32 percent for infants with more than one older sibling with autism. In short, nothing practical has changed in 11 years. I'm all about the practical, so what to do in 2011?

Answers could stem from the recent California Autism Twins Study (CATS), the largest ever study of twins with autism, which questions the scientific assumption that autism is genetic, instead pointing the finger at environmental causes. If autism is environmental, not purely genetic, we should be able to prevent and treat autism if we can determine the triggers. That's good news.

Talk to your doctor about steps you can take for an overall healthy pregnancy and to limit potentially harmful environmental exposures to your baby. Some suggestions are easier to swallow than those giant prenatal vitamins, like eat organic, healthy food and avoid household and work chemical exposures. Limit tuna and swordfish intake. If you opt for a flu vaccine, ask for a mercury free version -- available through county health offices or your pediatrician. You can also read "Healing and Preventing Autism: A Complete Guide," co-authored by Jerry Kartzinel, M.D.

If you do have a second child on the spectrum, your experience with your first will make the process easier. I hope I serve as proof that a family can thrive and prosper. Children aren't appliances, they don't come with warranties and guarantees. My girls are my joy. And while I'd take away their autism for their sake, their dad and I love them just the way they are.

At the end of the day, we simply don't know how to prevent autism, yet. The Combating Autism Act is up for re-authorization, and unless it focuses on treatment and prevention -- which means determining causation, along with caring for those who are here, like my three girls -- parents will live with this sword of Damocles over their heads forever. Tell your congressman, senator and doctor that treatment and prevention are a priority for this diagnosis that continues to grow faster than any other childhood disease. You can make a difference for your own children, and your grandchildren too.