The Babies of Teenage Boys are More Likely to Develop Autism, Spina Bifida and Schizophrenia

Wednesday, 18th February 2015

Scientists suggest that teenage fathers are more likely to have children with birth defects due to issues with their sperm.

Researchers at Cambridge University suggest that the male reproductive system might not function properly until several years after puberty.

Unexpectedly high levels of DNA mutations in teenage boys’ sperm cells were found, and this creates a 30 percent higher risk of babies being born with conditions such as spina bifida, schizophrenia and autism.

The scientists discovered that teenagers aged between 12 and 19 had sperm cells that experienced nearly one third more mutations than those of males in their 20s.

The study of 24,000 parents their children also found that male cells experienced six times more DNA mutations in the teenage years than women’s.

Published in the Proceedings of the Royal Society B journal, the research reveals that men’s sperm is healthiest when they are in their 20s and early 30s, before the number of cell mutations increases again the closer they get to 40 years old.

The study was carried out in Germany and Austria and led by Dr Peter Forster, who said that the findings are the first possible explanation for the rise in birth defects in children born to couples in their teenage years. He says that precisely why teenage boys have more mutations than older men is unclear. He believes that one explanation is that it takes time for the reproductive system in adolescents to work without fault. Alternatively, it could be that teenagers’ systems work faster, resulting in more errors.

Mutations take place when the DNA’s copying process incurs an error during cell division. Cell division is the process in which the male’s characteristics are passed into the sperm, before it is then passed on to the child.

Dr Forster says that the production of sperm in boys might undergo dozens more cell cycles than previously expected, therefore undergoing more DNA copying errors.

He went on to say that individuals should not feel worried regarding the findings as the numbers involved are very small. The average male has a 1.5 percent risk of fathering a baby with a birth defect. In comparison, the risk to teenage boys is 2 percent. This is a significant 30 percent increase when the population is looked at as a whole, but to the individual it is an indiscernible risk. Dr Forster points out that not every birth defect is caused by DNA mutation.