The age of parents and the risk of autism in children
The results of the largest international study to date have shown that a large age difference between parents increases the risk of developing autism in children. They also confirmed the previously identified pattern, according to which the older the parents, the higher the risk of having a child with autism.The authors came to these conclusions based on the results of an analysis of the frequency of autism among 5,766,794 children living in Denmark, Israel, Norway, Sweden and Western Australia. More than 30,000 of these children are diagnosed with autism. All children were born in the period from 1985 to 2004, their development was monitored until 2004-2009.
According to one of the initiators of the study, Professor Christina Hultman from the Karolinska Institute (Sweden), the collection of data stored in the medical registers of five countries made it possible to create a valuable information base for the study of autism.
Earlier studies have demonstrated the existence of a relationship between the age of parents and an increased risk of autism. However, experts still have a lot of questions, the search for answers to which was the purpose of conducting a new global study.
The authors identified other age-related factors that could potentially influence the risk of developing autism, and took them into account when conducting the analysis. In a separate analysis of the influence of the age of the mother compared with the age of the father, they took into account the age of the second parent. As a result , the following main results were formulated:
- The incidence of autism is 66% higher among children born to fathers over the age of 50 than in children whose fathers were 20 to 30 years old at the time of their birth. When comparing children whose fathers were 40-50 and 20-30 years old at the time of their birth, this indicator was 28%.
- The incidence of autism is 15% higher among children born to mothers after 40 years, compared with children born to mothers aged 20-30 years.
- The incidence of autism is 18% higher among children born to mothers in adolescence than among those born to women aged 20-30 years.
- The incidence of autism increases even more among children whose both parents are in the older age group, which confirms the contribution of the age of each parent to the level of risk.
- The frequency of autism also increases with an increase in the age difference between parents. The highest frequency is typical for children of fathers aged 35-44 years, whose mothers were 10 or more years younger than their fathers. Also, the high frequency of birth of children with autism is typical for couples where the mother is 30-40 years old and the father is 10 or more years younger.
The authors note that the results indicate a multiplicity of mechanisms that form the relationship between the age of parents and the risk of having children with autism spectrum disorders. But at the same time, do not forget that most children born to both young people and older parents develop normally.
Article by Sandin Sven et al. Autism risk associated with parental age and with increasing difference in age between the parents is published in the journal Molecular Psychiatry.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Karolinska Institutet: Large age-gaps between parents increase risk of autism in children.
19.06.2015