Prenatal Paternity: What Fathers May Pass Down

Fathers’ behavior and health factors may genetically alter sperm before conception

 

Dads can pass down more than a love of fishing to their kids, and they may do it unknowingly and before conception.

father holding a brand new babyThat’s right — what men do and what they’re exposed to before they ever contribute their sperm to a child’s conception may genetically alter their sperm, which could have effects on the health of their future kids. That’s according to an article by Jennifer Abbasi, a senior staff writer for JAMA.

Abbasi’s article takes a look at past research that suggests links between fathers’ preconception health factors and outcomes in their children. The premise her article relies on is this: Men’s epigenome, which regulates gene expression, can be altered and then passed down through their sperm.

That premise comes from multiple studies in rodents and a handful that found associations in humans, so the idea should be taken with a grain of salt, as Abassi notes.

Still, Abassi discusses research that found, for example, that exposure to environmental toxins in rodents may alter their epigenome and lead to infertility and other problems in their offspring.

Another study the article mentions is a review of research on both animals and humans. It found that a father’s weight, age, diet, alcohol intake and stress level prior to conceiving a child may be tied to his child’s risk for cancer, heart disease, diabetes, obesity, developmental disorders, behavioral problems and birth defects.

The effects of the paternal epigenome may even span multiple generations, according to one study Abassi writes about. This one looked at Swedish men who were born in 1905. If they had too little food before their sperm fully matured in puberty, their paternal grandchildren were less likely to die early. The opposite was true for men who weren’t exposed to hunger prior to puberty.

Abassi’s article also suggests that men don’t necessarily get a pass on smoking and drinking prior to conception. One study found that men who smoked before puberty were more likely to have heavier 9-year-old sons. Other research has found that dad’s drinking may contribute to symptoms in children similar to those seen with fetal alcohol syndrome: mild cognitive impairments, heart defects and low birth weight.

Abassi writes that many of these findings have been recreated in rodents in more controlled settings that could eliminate the effects of other factors, such as mothers’ drinking and smoking habits or environmental exposures.

This field of research is in its infancy, Abassi notes, but studies focused on men’s sperm are already starting to reveal epigenome signatures that are linked to specific outcomes in offspring.

Although more research is needed to make hard recommendations for men, Abassi writes that some research is suggesting that men can change some of their lifestyle factors that have effects on their sperm. Based on the current research, that could mean men can improve their diets, exercise, cut back on drinking, quit smoking and reduce their stress to make actual impacts on the health of their future kids.

And even if the current research isn’t quite right about the health effects men’s lifestyle factors may have on their kids before they conceive, changing those factors for the better probably couldn’t hurt.

References
JAMA Network, “The Paternal Epigenome Makes Its Mark”
http://jamanetwork.com/journals/jama/fullarticle/2625920?amp;utm_source=JAMAPublishAheadofPrint&utm_campaign=03-05-2017

Written by: Alex Lindley | Medically reviewed by: Dr. Robert Carlson, M.D.