Americans become parents at a later age than their predecessors, according to a Stanford University study released today that reflects that the average age has been delayed 3.5 years compared to 1972.
According to the study published today in the scientific journal Human Reproduction, the average age of first-time parents in 1972 was 27.4 years whereas in 2015 it was 30.9 years.
According to Dr. Michael Eisenberg, senior author of the study developed by the University School of Medicine, these changes tend to reduce the number of births and influence the configuration of the future workforce and other aspects of economic life.
“Less births mean fewer productive workers in the next generation,” Eisenberg said. “This can obviously have profound economic and tax implications,” added the researcher.
The research also found that parents of newborns over 40 years of age represent 9% of the total, more than double the 4.1% registered in 1972 in that same age group, whereas in the case of the elderly of 50 years is 1% and in 1972 it was 0.5%.
At the same time, older parents tend to have better jobs, more resources, more stable lifestyles, and more involvement in the training of children, the study found.
The analysis, which included all reported births in federal registries (about 169 million), also found that the age of mothers has also increased.
As a result, the age difference between father and mother has declined from 2.7 years in 1972 to 2.3 years in 2015, said study lead author Yash Khandwala and a member of the Eisenberg group when the research was conducted.
Part of the change is due, among other factors, to parents hoping to finish their studies to have children. Thus, the typical father with a college degree of a newborn is 33.3 years old.
“There are associations between older parents and higher rates of autism, schizophrenia, chromosomal abnormalities, some pediatric cancers and certain rare genetic conditions,” Eisenberg warned.
A study by the Pew Research Center today found that the annual number of births in the US declined by 4 percent between 1990 and 2015.