Preconception Experiences of Moms — and Dads — May Influence Babies’ Development
Emerging research explores how epigenetics and adults’ preconception experiences will affect their future children’s brains and behavior.
To what extent can parents’ experiences before conception influence their offspring’s development, behavior, and long-term health? It’s an increasingly common question that scientists can’t answer — at least not yet.
The link between parental experiences and child outcomes is well established, but research has generally focused on the prenatal period (e.g., the effects of smoking, stress, or diet during pregnancy) or the postnatal period (e.g., the impact of different parenting practices). More recent is the idea that parents may influence their children’s lives and health even before conception. In animal studies, exposure to trauma, alcohol use, or poor diet before conception has been found to alter epigenetic regulation in reproductive cells (eggs, sperm), influencing the offspring’s own epigenetic makeup and future behavior.
Epigenetics refers to a set of biological mechanisms that regulate when (in time) and where (in our body) genes are activated or switched off. Environmental exposures can influence these mechanisms.
The Challenges of Studying Humans
Most of the evidence for preconception effects comes from studies using animal models, which show that certain parental exposures before conception, such as diet and stress, can lead to differences in brain development, behavior, and disease risk in their offspring. While certainly thought-provoking, these findings currently pose more questions than they answer.
One such question: Do these findings generalize to humans? Clearly, experimental studies using animal models differ from human studies, which are typically observational. Animal studies can tightly control a subject’s environment and measure the effect of a specific exposure across generations while keeping all other factors constant (e.g., genetics or environmental factors). Such control is not possible with humans. Rather, studies in humans tend to measure as many variables as possible in an individual’s environment and life without interfering with them (observing rather than experimenting), which makes it much more difficult to establish causality.
So far, a handful of human studies have provided indirect support for preconception effects (e.g., the impact on offspring of parents and grandparents affected by World War II). However, it is difficult to establish whether preconception exposure or other related factors explain these effects. For example, preconception trauma exposure may affect parental mental health and increase risky behaviors, such as substance use, which may affect a child’s environment and development.
[New Class! The Adult’s Guide to ADHD Diagnosis]
Emerging Research on Epigenetics & Preconception
Multi-generational, well-characterized studies are beginning to emerge, opening unprecedented opportunities for exploring preconception effects in humans.
Another important question: Through what mechanisms do preconception effects occur? The effects may occur through epigenetic mechanisms influenced by the environment, affecting a person’s biology and health. Research suggests the link between parental experiences and offspring health outcomes may also occur along a biological route.
To what extent do these epigenetic mechanisms contribute to preconceptional effects in humans? To date, very few studies in humans have begun to explore epigenetic differences in sperm and eggs and whether they relate to their offspring’s health.
Moving the field forward will require large investments in studies that can collect epigenetic data in both parents and children and at different life stages (e.g., preconception, pregnancy, postnatal), which is expensive and logistically challenging. However, the rise of longitudinal multi-generational studies, together with the decreasing costs of epigenetic profiling and rapid methodological advances to handle this large and complex data, will soon enable us to overcome these barriers.
[Self-Test: Do I Have ADHD? Symptoms in Adults]
In the meantime, recognizing that both biological parents contribute to the health and development of the child, perhaps even before conception, is an exciting and important scientific development. This perspective helps counteract the focus on mothers, and it can serve to mitigate self-blame when a child is diagnosed with a condition. At the same time, we caution that the biological and epigenetic work on preconception effects largely relies on animal studies. Its relevance to humans is still unclear. However, we do know these possibilities warrant further human study.
Joel T. Nigg, Ph.D., is a professor of psychiatry and behavioral neuroscience and the director of the Center for ADHD Research at the Oregon Health & Science University in Portland, Oregon.
Charlotte A.M. Cecil, Ph.D., is an associate professor in biological psychopathology at the Department of Child and Adolescent Psychiatry at the Erasmus Medical Centre, the Netherlands.
Isabelle M. Mansuy, Ph.D., is a professor in neuroepigenetics at the Faculty of Medicine of the University of Zurich, Switzerland.
Epigenetic and Preconception Experiences: Next Steps
- Read: The Future of ADHD Research Looks Like This
- Read: Is ADHD Genetic? Yes and No
- Read: What Causes ADHD? Culture Vs. Biology
- Download: Free Guide to Health & Fitness: Lifestyle Changes for Adults with ADHD
SUPPORT ADDITUDE
Thank you for reading ADDitude. To support our mission of providing ADHD education and support, please consider subscribing. Your readership and support help make our content and outreach possible. Thank you.
