As societal trends shift across the United States and many adults wait until later in life to get married and start families, many researchers have taken an interest in examining the ways older parents are affecting their babies.
While the risks associated with older mothers have been documented for some time, a new study conducted by researchers at the Stanford University School of Medicine found that older fathers present a set of risks of their own for unborn babies -- and for pregnant mothers.
The researchers described “older age” as any father 35 years of age and older, and found that the older the father was, the greater the risk the baby had for complications.
“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,” said researcher Michael Eisenberg.
Understanding risk factors
Eisenberg and his team looked at data collected from both the Centers for Disease Control and Prevention (CDC) and the National Center for Health Statistics for over 40 million births across the country. They broke down each father’s age into the following groups: younger than 25; 25 to 34; 35 to 44; 45 to 55; and older than 55.
Perhaps the biggest takeaway from the study was that once a father hits 35, the baby is automatically at a higher risk of several different health complications. Men over 45 were 14 percent more likely to have a premature infant, and a 14 percent higher chance to be admitted into the NICU. Additionally, these babies were at a greater risk for seizures and lower birth weight.
When the father hit 50 years old, the baby was at an even greater risk for health developing health complications. They were 28 percent more likely to be admitted into the NICU and 10 percent more likely to need ventilation at birth.
Eisenberg also noted that the older the father is, the greater risk the mother has for developing diabetes while pregnant. Though the researchers are still trying to pinpoint why that is, Eisenberg suggests that the mother’s placenta could be a factor.
“Scientists have looked at these kinds of trends before, but this is the most comprehensive study to look at the relationship between the father’s age and birth outcomes at a population level,” Eisenberg said. “Having a better understanding of the father’s biological role will be obviously more important for the offspring, but also potentially for the mother.”
Consumers are waiting to have kids
Shifts across the societal landscape have led to many consumers waiting until later in life to start having kids. According to a study conducted by Stanford University last August, fathers of newborns are nearly four years older on average than they were 40 years ago.
Eisenberg was also involved in this study, and he discussed several risks associated with waiting to start a family.
“Every potential dad acquires an average of two new mutations in his sperm each year,” he said. “And there are associations between older fatherhood and higher rates of autism, schizophrenia, chromosomal abnormalities, some pediatric cancers, and certain rare genetic conditions.”
However, despite these risks, children born to older moms were found to be less likely to have behavioral problems.
Researchers from Aarhus University in Denmark found that older women -- though they face several risks like fertility issues and pregnancy complications -- are more likely to be more educated, have more stable relationships, and have better access to material resources. The researchers found that this can nurture a more positive emotional atmosphere for a young child, and help contribute to psychological maturity.