Aged parents who give birth late have more possibility to produce kids with autism, a study confirms. However, late birth was not linked with increased schizophrenia risk in children. It is only children birthed by very young mother who will likely develop schizophrenia, according to the study.
In the past, a lot of studies studying the effect of late birthing have formed variable results, sometimes because of extensive differences in study plan. But today, to try to solve the problem, researchers from the University of Copenhagen, Sean G. Byars and Jacobus J. Boomsma, use a very big sample.
For the study, they used a sample of around 1.7 million people from Denmark born from January 1978 through January 2009. After a thorough investigation, they have found out that about 6.5 percent were detected with schizophrenic and autistic disorders on this time. They then compared the risks of the children based on paternal and maternal age and the difference of parental age.
Result of the research via the Oxford Journals showed that maternal and paternal ages were linked with increased autism disorder risk in kids but not with schizophrenic disorder. However, in contrast, kids of younger parents had lessened autism risks and only kids of very young mom had increased schizophrenia risks.
"The magnitude of these increases and decreases in statistical risk need to be scaled against the fortunately rather modest absolute risks of being diagnosed with a mental disorder in Denmark, which is 3.7 percent for all autistic disorders and 2.8 percent for all schizophrenic disorders up to 30 years of age," Byars said to ScienceDaily. "The highest increases and decreases that we could relate to paternal and maternal age added only 0.2-1.8 percent to these absolute risks, but represented changes in relative risk of 76-104 percent," he added.
What's more, the study also talks about the reasons of the continuous existence of these risk patterns in contemporary human and recommends that they're remains of the evolutionary history. "Our evolutionary interpretations suggest how we can possibly understand recently increased mental disease risks that have no direct medical explanation," Boomsma remarked.
