Here’s why doctors probably shouldn’t delay having kids

By Liz Meszaros, MDLinx
Published May 10, 2019

Key Takeaways

It’s socially acceptable for men to delay having kids, especially when their career requires at least a decade of studies, such as with physicians. Consequently, many men in medicine tend to delay this milestone.

And—it’s not only the men in medicine who seem to be doing so.

Charlie Chaplin became a father at the ripe old age of 73. Robert DeNiro and Pablo Picasso were both 68 when their youngest children were born. And the list goes on: Steve Martin, became a father for the first time at age 67; Clint Eastwood, Nick Nolte, and Larry King were 66 when they had their youngest children; and Hugh Hefner, 65.

Pass the cigar and congratulate these men on their virility and vitality for being able to father children at such an advanced age.

But, wait. Maybe not.

According to a recent study published in The BMJ, men who conceive children at age 45 years or older may put both mother and child at risk for pregnancy complications such as gestational diabetes, premature birth, low birth rate, and low Apgar scores. These results are of particular import when held up to the backdrop of current trends in delaying parenthood, especially for men.

Recent trend of delayed parenthood

Since the 1970s, the percentage of fathers who are aged 40 years or older when fathering children has doubled in the United States. In 2015, for example, the number of infants born to older dads (over age 40) accounted for a full 9% of births. In previous research from 2017, Yash S. Khandwala, MD, surgery resident, Department of Urology, and senior author Michael L. Eisenberg, MD, assistant professor, Departments of Urology and Obstetrics and Gynecology, both at Stanford University School of Medicine, Stanford, CA, and colleagues concluded that mean paternal age has increased since 1972, from 27.4 to 30.9 years.

For male (and female) physicians, the decision to have children may be delayed by their medical training and the ensuing drain on not only their finances, but on their time and energy as well. Medical school and residency training usually coincide with one’s late 20s and can even stretch into the early 30s. For physicians in training, the decision to wait to have children may seem prudent.

Older women having children are considered to be at risk for several less-than-optimal outcomes, for both themselves and their children. Men having children at an advanced age, however, do not raise any such red flags.

Women are born with a lifetime supply of eggs, which—with time and age—degrade just like the rest of the cells and structures in the body. A man’s supply of sperm, however, is not bestowed at birth in lifetime quantities. Rather, sperm is produced regularly during a man’s life, during a 64-day cycle that comprises spermatogenesis. Therefore, the ravages of age and time were not thought to affect its viability or integrity.

A closer look at paternal age

In this retrospective, population-based study, Drs. Khandwala and Eisenberg and their colleagues assessed the effect of paternal age on maternal and perinatal outcomes between 2007 and 2016 in the United States in over 40 million documented live births, using data from the National Vital Statistics System.

They estimated that 13.2% of premature births (95% CI: 12.5% to 13.9%) and 18.2% of gestational diabetes (95% CI: 17.5% to 18.9%) in infants born to older fathers were due to advanced paternal age.

When they included maternal age in their analyses, Drs. Eisenberg and Khandwala and colleagues found that infants born to fathers aged 45 years or older had a 14% increased odds of premature birth (OR: 1.14; 95% CI: 1.13-1.15), and an 18% increased risk of seizure (OR: 1.18; 95% CI: 0.97-1.44) compared with infants of dads who were younger—aged 25 to 34 years. Finally, moms who had children with the oldest dads had a 34% higher risk of developing gestational diabetes. (OR: 1.34; 95% CI: 1.29-1.38).

These findings were bolstered by results from a previous study conducted by Dr. Eisenberg and coauthor Simon L. Conti, MD, clinical assistant professor, Department of Urology, also at Stanford University School of Medicine, in which they found a link between paternal aging and an increased risk of congenital diseases in infants, which included dwarfism, psychiatric conditions (eg, schizophrenia), and developmental conditions, such as autism. Furthermore, other researchers have documented increased risks of childhood leukemia, breast cancer, and prostate cancer in infants with older dads.

“As more than 12% of births to fathers aged 45 years or older with adverse outcomes might have been prevented were the father younger, the importance of these data are most relevant to parents planning their reproductive future. Preconception counseling guidelines might need to change to incorporate the possibility that delaying parenthood for fathers might not be as inconsequential as previously understood,” concluded Drs. Eisenberg and Khandwala.

In an opinion piece written to accompany their current study, Drs. Eisenberg and Khandwala elaborated more on the import of their findings in today’s modern, reproductive landscape.

“The father’s role in child birth is often ignored or forgotten, especially in pregnancies involving older mothers who undergo meticulous screening for early fetal loss and chromosomal abnormalities,” they wrote. “We discovered that we may no longer be able to ignore the potential impact that older fathers have on their offspring.”

The results of this study, and previous research, may render these widely held tenets obsolete.

“Our [current] study showed that delaying fatherhood is associated with negative effects on both infants and mothers. While there is still a significant need to evaluate the economic and public health implications of the association between advanced paternal age and pregnancy outcomes as well as the etiology of the association, couples may benefit from some preliminary counseling regarding the modest increase in risk to both mother and infant during pregnancy for older fathers (as well as older mothers),” concluded Drs. Khandwala and Eisenberg.

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