An untreated fever during pregnancy more than doubles the risk that the child will develop autism, according to a study published 5 May in the Journal of Autism and Developmental Disorders.

New tools developed as part of the Human Microbiome Project could help researchers understand the role of microbes in autism.

Two new postmortem studies show that microglia, which protect the brain from invaders, are denser and more concentrated around neurons in the brains of individuals with autism than in those of controls.

Immune cells called microglia may play a central role in trimming synapses, the connections between neurons, according to research published 24 May in Neuron. These modifications are part of a normal developmental process by which excess synapses in the brain are destroyed.

Health records of more than 14,000 people with autism show that they are more likely than the general population to suffer from a number of conditions, including immune disorders and gut problems. The results, published 12 April in PLoS One, suggest that doctors should carefully monitor their overall health.  

A biological signature in the blood could be used to aid the early diagnosis of schizophrenia, according to a study published 12 April in Molecular Psychiatry. The results suggest that various circulating immune molecules and metabolites reflect the biological changes that underlie neurological disorders.

Individuals with autism may belong to one of four groups with discrete sets of symptoms, the most distinct of which includes immune system abnormalities accompanied by sleep problems and sensory sensitivity. The results were published in the April issue of Autism Research.

Both premature and post-term babies develop more severe symptoms of autism than those born close to their due dates, according to a study published 16 March in the Journal of Autism and Developmental Disorders.

Full siblings are twice as likely as half siblings to share a diagnosis of autism, according to a short report published 28 February in Molecular Psychiatry. The results suggest that genetic factors play an important role in the risk of developing autism, the researchers say.

Molecules generated by an immune reaction in pregnant rats affect the brains of their offspring, leading to changes in gene expression, according to a study published 30 January in Brain, Behavior and Immunity.