Women are constantly reminded of their intersecting biological clocks and the risks associated with bringing children later in life –…
Women are constantly reminded of their intersecting biological clocks and the risks associated with bringing children later in life – both in maternity and child health, and the ability to understand a baby in the first place. But for the most part, you do not get the same warnings.
A new study published Wednesday in BMJ suggests that even men can have biological watches worthy to meet. Children born to older fathers, says the paper, may be more susceptible to health problems, including premature birth, low birth weight and breathing difficulties. And women who have older elderly children may also have an increased health risk – especially pregnancy diabetes.
“From an evolutionary point of view, we are used to reproducing in late teens, early twenties,” says study coauthor Dr Michael Eisenberg, director of male reproductive medicine and surgery at Stanford University Medical Center. “Everything but it may have some potential biological risk associated with it.”
Despite our evolutionary roots, American women have more and more children later in life, partly because many people work with careers and education before starting families. Father age seems to follow the same pattern. Between 1
972 and 2015, median age for paternity increased from 27.4 to 30.9 years, and the proportion of fathers over 40 increased to about 9%, a study from 2017.
Much has been made of the health problems associated with “geriatric pregnancies” such as higher odds for the previous child, birth weight with low infants and pregnancy diabetes and high blood pressure for the mother, both of which can affect the development of infants and lead to complications. Eisenberg and his colleagues decided to determine if similar dangers concern older fathers.
Using data from the National Vital Statistics System, they analyzed the over 40 million living born in the United States between 2007 and 2016. (During this period, the Middle Ages increased from 30 to 31.2 years.) They sorted The children of these children in five age groups – younger than 25, 25-34, 35-44, 45-54 and over 55 – and looked at child health measures within each of these categories.
After describing things like the age of the mother and the parents’ health and demographic information, researchers found a link between father’s age and likelihood of both the health and the child’s health problems. Significant associations began to be around 45 years old and the data indicate that older dangers, the higher the risk.
Compared with infants born to men aged 25-34, children with paper over 45 had a tendency to weigh less and had a 14% higher risk of premature birth. Babies born to men over 55 also tended to get lower scores on the Apgar test, a measure of newborn health that assesses things like heart rate, respiration and reflexes. These children also had a 10% higher risk of needing help and a 28% higher chance of being admitted to neonatal intensive care, researchers found.
Women with partners over 45 were also 28% more likely to develop pregnancy diabetes compared to women with partners between the ages of 25-34 years.
The new study joins previous research that has linked higher age with mental and behavioral health problems in children such as autism, hyperactivity disorder in attention deficit and bipolar disorder. While the reasons for these compounds, like those described in the new paper, are not entirely clear, they may have something to do with spontaneous genetic mutations that occur throughout the life of the human being, suggests research.
Men make continuous sperm, explains Eisenberg, which means that their cells constantly share and renew. Sometimes this process goes wrong, leading to approximately two random genetic mutations each year. The older a man is, the more of these mutations he accumulates over time, and the greater his chances of transmitting a harmful mutation, “says Eisenberg. Older men may also have experienced more epigenetic changes or modifications of DNA caused by the environment or lifestyle than younger men, he adds.
Eisenberg emphasizes that the absolute risk of child health problems remains small, even if the probability increases with the age of childhood. He is similar to the odds of buying lottery tickets: Your chance will be better if you buy two, but it’s still a long shot.
Eisenberg says, however, that accumulative evidence suggests that men should think carefully when they have children. “Most of the risk of being an older parent probably applies more to women than men, but I think this shows that you should not forget the man,” he says. “Men should not think of the track as unlimited.”