Children with autism whose mothers had immune conditions during their pregnancy are more likely to have behavioral and emotional issues, according to a new study from the University of California (UC) Davis. Researchers looked at maternal immune history as a potential predictor of symptoms in children with autism spectrum disorder (ASD).
“We tested the ability of maternal immune history to predict ASD symptoms and the possible role that the sex of the offspring plays,” said Dr. Paul Ashwood, professor of microbiology and immunology and faculty member at the UC Davis MIND Institute.
The findings, published in the journal Translational Psychiatry, also reveal that the sex of the fetus may interact with maternal immune conditions to influence outcomes, particularly in terms of a child’s cognition.
Previous research has shown that maternal immune conditions such as allergies, asthma, autoimmune diseases, autoinflammatory syndromes and immunological deficiency syndromes are more prevalent in mothers of children with ASD.
For the study, the research team enrolled 363 mothers and their children (252 males and 111 females) from the Autism Phenome Project (APP) and Girls with Autism Imaging of Neurodevelopment (GAIN) study at the UC Davis MIND Institute. The median age of the children was three years.
The team measured the children’s autism severity and then looked at the prevalence of a set of behavioral and emotional issues such as aggression and anxiety. They also measured the children’s development and cognitive functioning.
The researchers found that about 27% of the mothers had immune conditions during their pregnancy. Of these moms, 64% reported a history of asthma, the most common immune condition. Other frequent conditions included Hashimoto’s thyroiditis (hypothyroidism), Raynaud’s disease (blood circulation disease), alopecia (hair loss), psoriasis (skin disease) and rheumatoid arthritis (joint tissue inflammation).
The team also found that maternal immune conditions are linked to increased behavioral and emotional problems but not reduced cognitive functioning in children with autism.
The researchers also wanted to investigate whether the sex of the offspring interacts with the influence of maternal immune conditions on autism symptoms.
According to the Centers for Disease Control and Prevention (CDC), ASD is four times more common among boys than among girls.
“Our study explored whether offspring sex interacts with the presence of maternal immune conditions to influence behavioral outcomes in children,” said Ashwood. “Maternal immune conditions may be one environmental factor which contributes to the higher male prevalence seen in ASD.”
The findings show that a history of maternal immune conditions was more common in male children with ASD (31%) compared to female (18%). Specifically, asthma was twice as common in mothers of male children with ASD than in mothers of female children with ASD.
The researchers also found that in cases of ASD where maternal immune conditions are present, female offspring are less likely to be susceptible to adverse cognitive outcomes in response to maternal inflammation than male offspring.
“This critical finding links offspring sex and maternal immune conditions to autism,” said Ashwood. “It provides more evidence that male offspring are at higher risk of adverse outcomes due to maternal immunity activation compared to female offspring.”
Future research would include identifying the type, severity and gestational timing of immune conditions, and then examining offspring outcomes over time.