Men’s biological clocks may tick more like time bombs than metronomes according to 40 years of research data on male infertility. Synthesized by experts at Rutgers, the data on conception and the effects of fathers’ ages on their offspring indicates that babies born to older dads are more vulnerable to a variety of health complications, including premature birth, autism, and birth defects like congenital heart disease and cleft palates. As more men and women are able to conceive in their late thirties and forties with the help of reproductive technology, the findings raise questions about the future of family planning.
“While it is widely accepted that physiological changes that occur in women after 35 can affect conception, pregnancy and the health of the child, most men do not realize their advanced age can have a similar impact,” study co-author Gloria Bachmann, director of the Women’s Health Institute at Rutgers, said in a statement.
Doctors consider advanced paternal age to be anywhere from 35 to 45 and older men are more likely to give birth to children with health complication. One study found that when men over 45 were 14 percent more likely to have children born prematurely — this figure doubled for fathers over 50 — and significantly more likely to have pregnancies end in stillbirth. Other research showed babies born to older fathers are more likely to develop autism and future psychiatric problems as well. These babies were also more prone to low Apgar scores, low birth weight, seizures, and birth defects. Risks continued to crop up in childhood from there in the form of childhood cancers, autism, and psychiatric and cognitive disorders. Results also revealed that men 45 and older put mothers at risk as well, increasing the likelihood of pregnancy complications like gestational diabetes, preeclampsia, and preterm birth.
All that said, there’s evidence that, outside of these risks, there are a number of benefits to having children later in life, such as being more emotionally and financially stable caretakers. The number of babies born to men 45 and older has increased 10 percent over the past 40 years, underscoring a need for more information about the real risks of advanced paternal age, which has been significantly understudied compared to advanced maternal age. Bachmann and her colleagues suspect that the health issues faced by children of older fathers are the consequence of naturally declining testosterone and sperm quality that comes with age. The stress aging puts on sperm can cause germline or heredity mutations that may elevate health risks for mothers and children.
Older men struggled with infertility as well, even when their partners were as young as 25.
Bachmann and her team’s recent work marks the largest review of the literature to date and covers every study on “advanced maternal and paternal age and perinatal outcomes, childhood outcomes, maternal outcomes, male age and fertility, male age and assisted reproductive technology, advanced paternal age and schizophrenia, autism and offspring psychiatry” published over the past four decades in any scientific journal in good standing.
“In addition to decreasing fertilization potential, this can also influence the pregnancy itself, as is noted by increased pregnancy risks when conception is successful,” Bachmann said. “Although it is well documented that children of older fathers are more likely to be diagnosed with schizophrenia — one in 141 infants with fathers under 25 versus one in 47 with fathers over 50 — the reason is not well understood. Also, some studies have shown that the risk of autism starts to increase when the father is 30, plateaus after 40 and then increases again at 50.”
Although the past 40 years of research confirms that old dads are correlated with a number of risks, that does not mean that they cause them. The findings should not necessarily discourage men and women from planning their families on their own personal timeline but should encourage more research on an increasingly important subject. Bachman suggests that would-be fathers might best react to her findings by educating themselves about freezing sperm.