Before and during pregnancy, mothers usually bear the brunt of health scrutiny -- but, as urologist Michael Eisenberg emphasizes, fertility is a team sport.
A new study that takes a closer look at paternal health suggests chronic illness on dad's side puts newborns at greater risk for issues such as preterm birth, low birth rate and other conditions that require admittance to the neonatal intensive care unit, or NICU.
The research appears in Fertility and Sterility.
Past studies have shown how paternal age affects newborn outcomes, but far fewer have looked at the health-specific contributions of the father, said Eisenberg, MD, who led the study.
"Generally couples are not counseled about paternal health factors when they're trying to get pregnant and ultimately have a healthy child," he said.
Eisenberg's study, which analyzed data from 785,809 births in the United States from 2009 to 2016, aims to shed light on just how much influence dad's health has. The results suggest there's reason to pay closer attention to the father's health when couples are "trying."
The team looked at a variety of chronic paternal illnesses, including cancer, high blood pressure, diabetes and depression, paying attention to how babies with ill fathers fared at birth.
It turned out, the more chronic conditions the father had, the more likely the newborn would encounter an issue -- namely, low birth weight, preterm birth, or NICU admittance.
Analysis from the study showed that of these births, more than 6% occurred preterm, meaning the baby was born at 36 weeks or earlier. After adjusting the data to account for maternal factors, such as age and chronic illness, Eisenberg saw that fathers with chronic metabolic disease (such as diabetes) were about 20% more likely to have a newborn preterm or with a low birth weight, and had a 28% increase in risk for their child needing NICU care.
Parents and future parents -- take heed, but don't be too alarmed. The increase in these risks, though statistically significant, are still modest, for the most part, said Eisenberg.
"There isn't a whole lot known about how the dad's health before conception affects newborn babies," he said. "This study provides the data to say that the father's health can have important impact on birth outcomes."
For now, Eisenberg says the data is "hypothesis generating" and isn't a reason for doctors or fertility counselors to change how they approach their practice. "But it begins to change the paradigm of how we approach preconception counseling," he said.
"I don't want to be alarmist about this data. Generally speaking, most kids are going to do great, and most pregnancies are going to end up just fine," said Eisenberg. "But health risks of the father do impact the health of the child, and it's important to have all of the information when planning for a child."
Another interesting connection Eisenberg and his team found was between the father's health and that of the mother at birth. Although the mechanism is still unclear, there seemed to be an association between fathers with chronic illness and higher rates of both preeclampsia (marked by elevated blood pressure) and the more serious eclampsia (seizures) in their partners.
It's certainly intriguing, but whether it's a causative connection remains to be seen.
"Overall, I see this as another reason for men to pay more attention to their health and have more motivation to possibly make changes to lifestyle habits, such as diet or exercise." said Eisenberg. "If they know that their health has immediate impact on not only themselves -- but their baby and possibly their partner -- it could be another carrot that we can use to motivate them to enhance their health."
Photo by Mikael Stenberg