Research has hinted that various factors around the time of birth may raise a child’s risk of autism later in life, but there is still too little evidence to point to specific culprits, a US study said. Experts have long believed that genes play a key role in autism risk, but the study released last week found that genes appeared to explain a much smaller portion of the risk than previously suggested.
The latest study, a review published in Pediatrics, found that factors including low birth weight, fetal distress during labour and signs of poor condition in the newborn, such as problems with breathing or heart rate, have been linked to the risk of autism.
“There is insufficient evidence to implicate any one perinatal or neonatal factor in autism etiology, although there is some evidence to suggest that exposure to a broad class of conditions reflecting general compromises to perinatal and neonatal health may increase the risk,” said Hannah Gardener, a researcher who led the study when she was at the Harvard School of Public Health.
The current findings, Gardener said, underscore the importance of continuing to study which environmental factors — whether before, during or after birth — may act in concert with genetics to cause autism. Gardener and her colleagues found that a number of factors were linked to autism, including multiple birth, birth injuries to the baby, problems with the umbilical cord, maternal haemorrhaging during childbirth, and anaemia or jaundice.
While none of these alone could be linked to a greater autism risk, exposure to a number of those factors might have an impact — possibly due to general compromises to a newborn’s health.
Published in The Express Tribune, July 14th, 2011.