Fathers' weight, stress, and childhood experiences shape their children's health before conception
Who is responsible for a healthy pregnancy? The medical system's answer, historically, has been clear: the mother. Prenatal vitamins, dietary guidance, substance cessation programs, weight management - virtually all preconception and prenatal health interventions target the person who will carry the child.
A new review published in The Lancet argues that this framing is not just incomplete. It is scientifically wrong and socially harmful.
The biological case for fathers
The review, led by Jonathan Huang of the University of Hawai'i with senior author Professor Keith Godfrey at the University of Southampton and the NIHR Southampton Biomedical Research Centre, synthesizes evidence from biological, behavioral, and social sciences into a single framework for understanding men's role in pregnancy preparation.
The biological evidence is striking. A father's weight, substance use, age, and environmental exposures can all influence pregnancy outcomes and child health through mechanisms that do not depend on the mother's behavior. Paternal obesity, for instance, has been linked to epigenetic changes in sperm that affect offspring metabolic health. Paternal smoking alters sperm DNA methylation patterns. Paternal age correlates with increased risk of certain developmental conditions.
"For some aspects, the influence of the father is even stronger than that of the mother, with some of these fathers' effects linked to experiences from their own childhood," Godfrey said. That last point is particularly important: a man's early life experiences - stress, adversity, nutrition, environmental exposures - can leave biological marks that carry forward into the next generation.
Beyond biology: the partner effect
The review goes further than genetics and epigenetics. A father's mental health, stress levels, and social circumstances shape the environment in which pregnancy occurs. Dr. Danielle Schoenaker, a co-author from the University of Southampton, summarized the pathway: "A man's early life experiences, including stress, physical and mental health, environment, and education, influence his health during his reproductive years. These factors can, in turn, affect his partner's health and health behaviours before and during pregnancy, as well as having direct biological effects on the developing infant."
A partner who smokes makes it harder for a pregnant person to quit. A partner experiencing untreated depression may provide less support during a high-risk pregnancy. A partner's financial instability introduces stress that has its own physiological consequences. These are not peripheral factors. They are upstream determinants that the current system largely ignores.
Racism, colonialism, and disrupted fatherhood
The researchers explicitly address how structural inequalities shape paternal health - and how ignoring fathers in preconception care reinforces those inequalities.
Lead author Jonathan Huang framed this directly: "Racism and colonialism have disrupted family and community roles for many Black and brown men, creating barriers to addressing their health needs. This disruption underscores the need for culturally grounded approaches."
The review argues that policies and programs need to strengthen family and community bonds while centering men's health within their cultural roles - not as an afterthought to maternal care, but as an independent priority with intergenerational consequences. Improving health outcomes for future children requires addressing the health disparities affecting future fathers, many of which are rooted in systemic racism, poverty, and historical displacement.
The ethical problem with mother-only frameworks
The researchers note an uncomfortable truth about the current approach: placing all responsibility for a child's health on the birthing parent reinforces gender biases. It treats pregnancy as solely a woman's domain while ignoring the male biological contribution, the partner's behavioral influence, and the shared social context in which families form.
Godfrey was direct about the reframe: "Investing in the well-being of boys and young men is key to reducing health disparities and improving outcomes for future generations. Raising awareness about the importance of men's health does not diminish the critical importance of women and pregnant persons' well-being. Rather, it serves as a collective call to ensure that men and partners are equipped to be supportive partners, allies, and caregivers before, during, and long after pregnancy."
What would change look like?
The review does not provide a specific policy blueprint, and the researchers acknowledge that translating its framework into clinical practice will require further work. Most healthcare systems are not designed to engage men in reproductive health conversations. Primary care visits for young men are infrequent. Preconception health messaging overwhelmingly targets women. Clinical guidelines rarely address paternal risk factors.
Changing that requires action at multiple levels. Policymakers need to fund research on paternal preconception health. Public health campaigns need to include men as active participants in pregnancy preparation, not passive bystanders. Clinicians need screening tools and conversation frameworks for discussing reproductive health with male patients. And researchers need longitudinal data on how paternal health interventions affect offspring outcomes - data that barely exists.
The study was a collaboration between the University of Southampton, University College London, and partners in the United States, New Zealand, and Singapore.