Many studies have examined the association between parental age and medical risks in offspring (read “Is it time to establish age restrictions in ART-IVF?, a relevant bioethical issue that also focuses on the access of older patients to reproductive technologies), and indeed in our Observatory, we have often addressed the current trend to delay motherhood in our society and its medical effects (read HERE).
Several studies have associated the mental health of offspring with paternal age, concluding that it has a significant impact. A more recent study published last December in Science Direct, entitled, Parental age and risk of depression: a nationwide, population-based case-control study comprised 37,682 singleton births in Finland that had a depressive disorder recorded in the Care Register for Health Care. It concluded that “Both maternal and paternal age was U-shaped associated with offspring depression”.
Risk of schizophrenia
From a bioethical point of view, these studies are relevant, as the age of parenthood is undergoing a global shift. While we cannot mention all the studies conducted in many countries on this issue, we would like comment on a study published in the Journal of Assisted Reproduction and Genetics, entitled, Association between paternal age and risk of schizophrenia: a nationwide population-based study, as it reports severe psychiatric illness, supported by a large study carried out in Taiwan.
As far as we know, this is the largest study ever to associate paternal age and schizophrenia. The study methodology details how “[d]ata from Taiwan’s National Health Insurance Research Database were utilized to answer the research question. A total of 17,649 offspring with schizophrenia were selected from 11 million offspring in the general population. Additionally, we established the offspring without schizophrenia as the comparison group by matching the study cohort by age […]”.
The authors concluded that “[the] study indicated that advanced paternal age increased the risk of schizophrenia in offspring. Offspring born to fathers older by 5-year increments were at heightened risk of schizophrenia.”
This finding shows that each 5-year age increase in the father’s age, beginning with 20-year-old fathers, increases the odds of being diagnosed with schizophrenia. This conclusion shows the increased risk for offspring of the new social trend of delayed parenthood in our society and the practice of fertility clinics given access to older couples to produce babies.