Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Autism Spectrum Disorders Health Center

Font Size

Allergies, Asthma May Play Role in Autism

Expectant Moms With Allergies and Asthma Give Researchers 'Tantalizing Clue' About Autism
WebMD Health News

Feb. 7, 2005 - Allergies or asthma during pregnancy may increase the risk of giving birth to a child who develops autism.

Investigators caution that the association must be confirmed, and that the increase in risk observed in a study was quite small. The findings are reported in the February issue of the Archives of Pediatrics and Adolescent Medicine.

"This is a modest effect, and it is the first time, to my knowledge, that it has been reported," lead researcher Lisa A. Croen, PhD, of the Kaiser Foundation Research Institute tells WebMD. "These findings certainly need to be replicated. But this gives us some interesting clues to pursue."

Second Trimester Riskiest

The researchers also investigated, but failed to find, a link between autism and a family history of autoimmune diseases like lupus, type 1 diabetes, and rheumatoid arthritis. Earlier studies had suggested such a link, but most relied on self-reported data. Autoimmune disorders occur when the body mistakenly attacks normal tissues as if they were foreign.

Croen and colleagues examined the medical records of more than 88,000 children born between 1995 and 1999 in Northern California. Of these children, 420 were later identified as having autism or a related disorder. These cases were compared to 2100 nonautistic children of similar sex, age, and birth hospital.

The researchers found that expectant mothers with asthma diagnosed in the second trimester were twice as likely to have a child that developed autism. The researchers found no risk among women found to have asthma during the third trimester.

The risk was smaller for women with allergies. The only significant effect was for women diagnosed with allergies in the second trimester. These women were 2.5 times as likely to have a child that developed autism.

Clues About Where to Look Next?

Although the causes of autism are not well understood, genetic predisposition is considered to play a major role. A few environmental triggers have also been identified, including prenatal exposure to certain chemicals.

Andy Shih, PhD, tells WebMD that what we now lump together as autism is likely to end up being several related, but distinct disorders. Shih is chief science officer for the National Alliance for Autism Research.

Today on WebMD

girl at window
Symptoms within the first 2 years of a child’s life.
boy playing a violin
How is this condition similar to autism?
Mother and daughter indoors playing
Play therapy may undo the disorder in at-risk babies.
preschool age girl sitting at desk
What causes this rare form of autism?
High Functioning Autism And Asperge Syndrome
Gluten Free Diet Slideshow
Mother and daughter indoors playing
man on bicycle
girl at window
Mother hugging teenage son
Understanding Rett Syndrome
Home Care Tips

WebMD Special Sections