as people wait longer and longer to procreate, new problems emerge.

A mass study found that deaths of children fathered by over-45s occurred at almost twice the rate of those fathered by men aged between 25 and 30.

children of older fathers are more likely to suffer particular congenital defects as well as autism, schizophrenia and epilepsy.
researchers believe the findings are linked to the declining quality of sperm as men age.

A total of 100,000 children born between 1980 and 1996 were examined, of whom 830 have so far died before they reached 18, the majority when they were less than a year old.

The deaths of many of the children of the older fathers were related to congenital defects such as problems of the heart and spine, which increase the risk of infant mortality. But there were also higher rates of accidental death, which the researchers believe might be explained by the increased likelihood of suffering from autism, epilepsy or schizophrenia.

The research also found higher death rates among children of the youngest fathers, especially those below the age of 19. However, the study said these differences were explained by the risks of teenage motherhood and poorer diet and lifestyle.

Previous research using the same data found that older men were four times as likely to father a child with Down's syndrome, while other studies have found that the genetic quality of sperm deteriorates as men age.