Autism risk tied to mom's obesity during pregnancy

Autism is more likely to occur in children whose mothers were obese while pregnant, new research suggests.

The study, one of the first of its kind, involved about 1,000 California children, ages 2 to 5. Researchers affiliated with the UC Davis MIND Institute looked at their mothers' medical records and examined the association between obesity and autism. Women who were obese during pregnancy were about 67 percent more likely than normal-weight women to have autistic children, the study showed. Obese moms also faced double the risk of having children with other developmental delays.

Children born to obese women are more likely to be diagnosed with autism or related developmental delays than the children of slimmer mothers, according to a U.S. survey. 

The research, which appeared in Pediatrics, was looking for the impact on childrens' cognitive development from a variety of "metabolic conditions" in the mother, including high blood pressure or diabetes. The strongest links were found between obesity and autism-related disorders.

Although the study cannot prove that one condition causes the other, its authors caution that even the possibility is worrisome in the light of rising U.S. obesity rates.

Obesity isn't the only risk factor found for pregnant moms in the study. Researchers also looked at prevalence of gestational diabetes and found pregnant moms with diabetes had nearly 2 1/3 times the chance of having a child with developmental delays compared with healthy mothers. Although the proportion of diabetic mothers who had a child with autism was higher, the numbers did not reach statistical significance.

The study was published online in the April 9 issue of Pediatrics.

Among the children in the study with an autism spectrum disorder, 48 were born to mothers with Type 2 or gestational diabetes, 111 to mothers who were obese and 148 to mothers with any sort of metabolic condition, like high blood pressure.

For children with a developmental delay, 20 were born to mothers with Type 2 or gestational diabetes, 41 to mothers who were obese and 60 to a mother with any metabolic condition.

What explains the results? Researchers say the study does not indicate cause and effect - and further research must be done to confirm the results. But the authors theorize that obesity - generally about 35 pounds overweight - is linked with inflammation and sometimes elevated levels of blood sugar. Excess blood sugar and inflammation-related substances in a mother's blood may reach the fetus and damage the developing brain, study author Paula Krakowiak, an epidemiologist at the University of California, Davis, said.

Of those children, 517 had an autism spectrum disorder and 172 had developmental delays. For Krakowiak's study, the children's diagnoses were confirmed by a re-evaluation at the UC Davis MIND Institute.

Milder versions of autism, such as Asperger's syndrome, form a "spectrum" of autism-related disorders. In addition, impairments in any one of the autism-related cognitive skill areas are considered developmental delays.

On average, women face a 1 in 88 chance of having a child with autism, according to recent CDC figures. The new research suggests that obesity during pregnancy would increase that to a 1 in 53 chance, the authors said.

"Over a third of U.S. women in their childbearing years are obese and nearly one-tenth have gestational or type 2 diabetes during pregnancy," Krakowiak said in a written statement. "Our finding that these maternal conditions may be linked with neurodevelopmental problems in children raises concerns and therefore may have serious public-health implications."

Previous research has linked obesity during pregnancy with stillbirths, preterm births and some birth defects.

"There is a lot that is unknown and studies like these really help us figure out the questions that need to be answered," Gardener said.

But she warned that researchers are far from understanding what might create a link between obesity and autism.

U.S. autism rates have increased along with obesity rates, says Dr. Daniel Coury, chief of developmental and behavioral pediatrics at Nationwide Children's Hospital in Columbus, Ohio. He said the research suggests that may be more than a coincidence.

If mothers' obesity is truly related to autism, it would be only one of many contributing factors, said Coury, who was not involved in the study.

What other factors have been linked to autism? Genetics, mothers' illnesses and use of certain medicines during pregnancy are a few, according to the CDC.

Although the study looked at obesity in the mothers, it lacks information on women's diets and other habits during pregnancy that might have influenced fetal development.

The CDC has more on pregnancy complications, including obesity and gestational diabetes.

Vaccine Protect from Influenza (Flu)

Infants and children aged <5 years, but especially younger than 2 years old, are at increased risk for severe complications from influenza.

School-age children had a substantial illness burden caused by influenza that vaccine was safe and effective for children aged 6 months through 18 years, and that evidence suggested that vaccinating school-age children would provide benefits to both the vaccinated children and their unvaccinated household and community contacts.

The implementation of an annual recommendation for all school-age children would pose major challenges to parents, medical providers and health care systems. Alternative vaccination venues were needed, and of these school-located vaccination programs might offer the most promise as an alternative vaccination site for school-age children.

CONCLUSIONS Expansion of recommendations to include all school-age children will require additional development of an infrastructure to support implementation and methods to adequately evaluate impact.

An intranasal vaccine that includes four weakened strains of influenza could do a better job in protecting children from the flu than current vaccines, Saint Louis University research shows.

Vaccine Protect from Influenza of Children.

Before each influenza season, scientists predict which strains of flu will be circulating and make a trivalent vaccine that includes three strains of influenza -- two of influenza A and one of influenza B.

The ability to add another strain of influenza B without compromising the vaccine's ability to protect against the other three strains will allow scientists make a better vaccine, said Robert Belshe, M.D., professor of infectious diseases at Saint Louis University School of Medicine and the corresponding author of the research article.

"The vaccine improves our ability to protect against flu and doesn't reduce the body's immune response to the other strains," said Belshe, who also directs Saint Louis University's Center for Vaccine Development.

"It should bring us better protection because there's less guess work than in the standard trivalent vaccine."

Children are more susceptible than adults to influenza from one of the B strains, which change less often than A strain viruses. Some winters, influenza B viruses -- Victoria or Yamagata -- cause most of the flu in children and significant infection in adults, Belshe said.

Preventing flu in children is key to protecting the entire population. "We think the most important way for flu to spread is through school-aged children," Belshe said.

In the 1980s, influenza B split into the two circulating lineages of virus, which have evolved into viruses that are quite different. Some years both B viruses and the B strain that doesn't match the vaccine circulate, which means the vaccine doesn't protect people from getting the flu?

"There are these two very different strains of influenza B that don't cross protect. Vaccinating against one strain of influenza B does little to protect against the other," Belshe said.

"It has not been possible to predict which strain has circulated. In the last 10 years, we predicted right five times. So you can flip a coin and do as well."

Previously, manufacturers had not had the capacity to produce a vaccine that protects against four strains of flu, but that is no longer the case, Belshe said.

The researchers tested versions of the FluMist vaccine, which is sprayed in the nose and contains live flu viruses that have been attenuated or weakened so they don't cause infection. The intranasal vaccine is made by MedImmune.

The nasal spray vaccine was tested in about 2,300 children between 2 and 19 years of age. The children were randomized to receive one of three vaccines: a vaccine containing four strains of influenza -- two of influenza A and two of influenza B, or one of two vaccines that contained both influenza A strains and one of each of the influenza B strains. Researchers looked at the safety and antibody response to both influenza A and B viruses in children of different age groups who were vaccinated.

Those children who receive vaccine containing four strains of flu had as robust of an immune response as those who received the vaccine that contained three strains. In addition, Belshe noted no clinically significant difference the safety of the vaccines, which were well tolerated.

"We saw stuffy noses, which we know is associated with FluMist, and an occasional low grade fever, which is similar to other childhood vaccines," Belshe said.

Findings were published electronically ahead of print in the Pediatric Infectious Disease Journal. Belshe has been a member of a speaker's bureau and received research grants and consulting fees from MedImmune, which sponsored the study.

What is the best way to prevent influenza?

What does this year’s vaccine protect me from?

The best way to prevent influenza is with annual vaccination.

The 2011-2012 flu vaccine protects against an influenza A H3N2 virus, an influenza B virus and the 2009 H1N1 virus. Seasonal flu vaccines have a very good safety track record. Cover your nose and mouth with your sleeve or a tissue when you cough or sneeze—     throw the tissue away after you use it. Wash your hands often with soap and water, especially after you cough or sneeze. If you are not near water, use an alcohol-based hand cleaner.