We know it's so important to take care of ourselves every day—not just during and after pregnancy, but before you even try to conceive, too. But it's not just mamas-to-be who have to watch their health when they're trying to conceive. New research shows a dad's preconception health can also have a significant effect on a baby's development.
Three new studies published in The Lancet this month found that, among other factors, how healthy a man is before conception can also determine the lifelong health of their baby, and even future generations. Looking at four different areas—maternal obesity, maternal underweight, paternal factors, and use of assisted reproductive treatment—researchers found that, as with a mom-to-be, a dad-to-be's preconception health can influence a child's long-term risks for neurological, immune and metabolic problems, as well as issues with their hearts.
Speaking to CNN, senior scientist Milton Kotelchuck, who was not involved with the studies, says, "This is a really important series, and it is important because it helps further re-establish the importance of preconception care as a legitimate direction for improving birth outcomes and improving health in children, both at the time of birth but also over their life course."
In particular, the studies discovered that paternal physiology, body composition, metabolism and diet can increase their baby's risk of developing chronic disease—what the researchers called "a lifetime legacy and major driver of health burden in the 21st century," according to CNN.
In fact, a 2016 study published in Fertility and Sterility found that both dads and moms who drink more than two caffeinated beverages a day have about a 74% greater risk of experiencing miscarriage. Although the link between caffeine and pregnancy loss is unclear, researchers at the time suggested the substance may "turn off" certain sperm or egg genes, according to HealthDay.
But preconception health is more than whether or not they have strong sperm or a strong sperm count. Previous research involving animals showed that a dad-to-be's health can affect on how well a placenta develops and is nurtured. A 2013 animal study Proceedings of the National Academy of Sciences study discovered that the genes of the animal father were predominate in the placenta, suggesting that a dad's well-being plays an important role in their offspring's development beyond sperm.
"Does he help the woman or harm her in getting prenatal care? Does he give support or not support? ... Does he have sexually transmitted diseases?" Koletchuck tells CNN. "The father's genes also are very important in the development of the placenta and whether the placenta's nurtured well enough."
A dad's preconception diet is also a key factor to a child's future health. Two animal studies published in 2016 found that what male mice ate altered the metabolism of their offspring through RNAs, small molecules essential to gene expression, according to Today. Particularly, daughters of male mice given a high-fat diet had weakened glucose tolerance and insulin resistance, while pups of male mice on a low-protein diet saw changes in their cholesterol metabolism.
So what should dads do to make sure they're the healthiest they can be before they conceive? Experts suggest it's as simple as keeping a nutritious diet and reducing everyday stress. But more importantly, they say, doctors need to take more time to talk to men about their preconception health in the first place.
"There's very little talking to men. There's almost no brochures that speak to men and men's interests," Kotelchuck says. "If you do preconception care for women because you're interested in the health of not only the baby but also the woman over her life course ... you have to talk to dads in the same way."