Giant research strengthens hyperlink between autism, preterm start | Spectrum
Small possibility: about 2 percent of premature babies will later be diagnosed with autism, according to a new analysis.
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According to the largest study to date to investigate the link, premature birth is linked to an increased risk of autism. And premature birth itself – and not unrecognized genetic or environmental factors – seems to underlie the association.
The results suggest that premature infants need early evaluation and long-term follow-up to aid in the timely detection and treatment of autism, experts say.
“We know that early intervention can have a huge impact on later outcome, and increasingly more effective interventions are available,” said April Benasich, professor of developmental cognitive neuroscience at Rutgers University in Newark, New Jersey, who does not participated in this study.
Previous research suggests that premature babies – before 37th. Almost 11 percent of births worldwide are premature babies, and more than 95 percent of these babies survive with modern neonatal care.
“Our work so far has shown that most premature babies survive into adulthood without neurodevelopmental disorders or other chronic health problems,” says study leader Casey Crump, professor and assistant chair of research in the Department of Family Medicine and Community Health at the Icahn School of Medicine on Mount Sinai in New York City.
However, researchers have long debated whether premature birth contributes to autism or whether both diseases could share genetic or environmental influences. It was also unclear whether the link had a gender bias or whether it extended to premature birth – during the 37th and 38th weeks of pregnancy – which is about three times more common than premature births.
In the new study, researchers searched the national health and birth registers to analyze data on more than 4 million people born in Sweden between 1973 and 2013.
“I was overwhelmed by the size of the cohort,” says Benasich.
Both premature and premature births were significantly associated with an increased likelihood of autism in boys and girls. The earlier a baby was born, the higher the likelihood of developing autism, the team found: About 6 percent of those born in weeks 22 to 27 of pregnancy have autism, compared with 2.6 percent of those born in weeks 28 to 33 1.9 percent of those born between weeks 34 and 36 and 1.6 percent of those born between weeks 37 and 38. In contrast, 1.4 percent of babies born between the 39th and 41st weeks have autism.
The scientists detailed their results online today in Pediatrics.
Comparisons with siblings also showed that the relationship between preterm birth and autism cannot be primarily explained by common genetic or environmental factors within the family. Instead, premature birth itself can slightly increase the likelihood of autism in an infant.
“Although the relative risk of autism was significantly higher in preterm infants than in whole babies, the absolute risk was still low – for example, only 2.1 percent of preterm infants were diagnosed with autism,” added Crump.
Premature birth could increase the likelihood of autism due to inflammation of the brain and nervous system, suggest Crump and colleagues. Premature babies often have altered connectivity between different parts of the brain, which could also be the reason for the neural development problems common in this group, says Benasich. Understanding how such mechanisms contribute to autism in premature or premature babies could shed light on the causes of autism in general, she says.
“A better understanding of the mechanisms could potentially reveal new points of attack for interventions in critical windows of neural development,” says Crump.
Future research should collect individualized prenatal, perinatal, and postnatal data to analyze what infants experience in the neonatal intensive care unit, Cheng Kung National University Hospital in Tainan, Taiwan, which did not participate in this work.
Although the new study is limited to data from one country, Crump says, “we expect the results are likely to be transferable to other settings, but they should be replicated in other populations if possible.”
Quote this article: https://doi.org/10.53053/OZCR4687