Children born to fathers above the age of 35 are at a higher risk of having birth defects: Study
A study published in the British Medical Journal tracking 40 million babies found a significant risk increase when fathers hit their 30s
Researchers have claimed that in order to avoid various risks to unborn babies, men should start a family before the age of 35. The risk of birth complications start to increase when fathers are in their mid-30s and rise considerably after the age of 45, a study tracking the births of 40 million babies concluded.
Women have been warned for decades that if they pursued a career first and left it until they are older to have a family, they would be putting the health of their children at risk. That said, men should also take responsibility for the same, the new study published in the British Medical Journal asserted.
Professor Michael Eisenberg, a researcher at the Stanford University School of Medicine, said: "We tend to look at maternal factors in evaluating associated birth risks. But this study shows that having a healthy baby is a team sport, and the father's age contributes to the baby's health, too."
A slight increase in birth defects was observed once a father hit 35. However, the risk increased sharply as men aged into their 40s and 50s, Eisenberg said. According to him, every year that a man ages, he accumulates two new mutations in the DNA of his sperm. Infants born to men between the age of 35 and 44 were about five percent more likely to be born premature or with low birth weight as compared to fathers between the ages of 25 and 34.
For a father above 45, his children were 14 percent more likely to be admitted to intensive care, to be born prematurely, and to have a low birth weight. Also, they were 18 percent more likely to have seizures, the study determined.
It got worse if the father crossed 50 years of age, when the likelihood of their children needing ventilation upon birth increased by 10 percent, while the probability of them requiring intensive care increased by 28 percent, Daily Mail reports.
Professor Eisenberg added: "What was really surprising was that there seemed to be an association between advanced paternal age and the chance that the mother would develop diabetes during pregnancy." While possible biological mechanisms at play for men aged 45 and older are still to be established, he suspects that the mother's placenta has a role.
According to the Office of National Statistics, around 18 percent of children born in England and Wales have a father aged 40 and above. Eisenberg says that while the average age of fathers has been significantly increasing over the past two decades, the absolute risks associated with the same are still relatively low.
Comparing the increased risks to buying lottery tickets, he said. "If you buy two lottery tickets instead of one, your chances of winning double, so it's increased by 100 percent. But that's a relative increase. Because your chance of winning the lottery started very small, it's still unlikely that you're going to win the lottery. This is a very extreme example, but the same concept can be applied to how you think about these birth risks."
Having said that, the researchers wrote: "A significant number of these negative birth outcomes were estimated to be prevented if older fathers had elected to have children before the age of 45 years. The risks associated with advancing paternal age should be included in discussions regarding family planning and reproductive counseling."