For decades, science has recognised that genes carry the blueprint of life. Children inherit half their DNA from each parent, including variants that influence susceptibility to conditions such as diabetes, cardiovascular disease, obesity, and mental health disorders. Yet, genes are not destiny. A growing body of evidence has proven that child health begins well before birth, shaped by the health and behaviour of both parents, not just by the genes. This is extensive practical relevance.
The research findings from the Avon Longitudinal Study of Parents and Children (ALSPAC) — a UK-based cohort that has followed nearly 14,500 pregnancies — and analyses published in The Lancet Child & Adolescent Health (2023) show that with the same genes but exposure of parents to environmental factors can affect future children. A BMJ Open (2022) study links maternal stress during pregnancy with epigenetic changes and later cardiovascular risk markers, while the findings in Wellcome Open Research (2023) underscore the independent role of paternal health.
Epigenetics refers to changes in gene activity that do not alter the DNA sequence but determine how genes are “switched on or off”. These changes are highly responsive to environmental and behavioural factors, particularly during sensitive periods such as pre-conception and early development. Increasingly, evidence shows that the health status of parents — even before pregnancy — can leave lasting biological imprints on their children.
This is where the concept of pre-conception health becomes critical. It shifts the focus from treating illness after it appears to shaping health before life even begins. Pre-conception health is not merely about avoiding disease; it is about optimising nutrition, maintaining a healthy weight, managing stress, avoiding harmful substances, and ensuring overall physical and mental well-being in both women and men of reproductive age.
The biological pathways through which this influence operates are now well documented. Tobacco exposure, for instance, has been shown to alter DNA methylation patterns in offspring when either parent smokes before conception. These changes affect genes linked to immunity, metabolism, and lung function, increasing the risk of asthma, obesity, and metabolic disorders. Similarly, maternal smoking is associated with low birth weight and a paradoxical increase in the risk of obesity later in life. Global estimates suggest that around 14.4% of mothers and 27.5% of fathers smoke during pregnancy, exposing millions of children to preventable risks.
Obesity and poor nutrition represent another major pathway. Parental obesity, particularly maternal, is associated with increased risks of obesity, diabetes, and cardiovascular disease in children. These effects are mediated not only through shared genes but also through intrauterine and epigenetic mechanisms. The metabolic environment of the parent can influence gene expression patterns in the developing embryo, predisposing children to chronic diseases across their lifespan.
Physical inactivity, stress, and other lifestyle factors further compound these risks. Emerging evidence suggests that the cumulative effect of parental behaviour may, in some cases, rival or exceed genetic predisposition in determining child health outcomes. The implication is clear: improving the health of prospective parents can have far-reaching benefits for the next generation.
Recognising this, professional bodies such as the Indian Academy of Paediatrics has highlighted the need to integrate preconception counselling into routine healthcare, focusing on nutrition, micronutrient supplementation (particularly folic acid), and lifestyle modification. Similarly, the Federation of Obstetric and Gynaecological Societies of India recommend pre-pregnancy screening for anaemia, diabetes, and thyroid disorders, alongside counselling on healthy weight, avoidance of tobacco and alcohol, and mental well-being.
Staying healthy before conception is not just a personal choice; it is an investment in the health of future generations. In the short term, better preconception health reduces the risk of complications such as low birth weight, preterm birth, and congenital anomalies. In the long term, it lowers the risk of non-communicable diseases such as diabetes, hypertension, and cardiovascular disease in offspring. These are not trivial gains. India is already facing a growing burden of chronic diseases, and a significant proportion of this risk may be shaped early in life — even before birth.
There are also substantial economic implications. Preventing disease through improved preconception health can reduce healthcare costs associated with neonatal intensive care, chronic disease management, and long-term disability. For families, this translates into lower out-of-pocket expenditure and reduced financial stress. At a societal level, it means a healthier, more productive population and a reduced burden on healthcare systems. These are indirect benefits, often invisible in the short term, but profoundly important over time.
Yet, despite its importance, pre-conception care remains underdeveloped in many health systems, including in India. Healthcare often begins with pregnancy or even later, missing a critical window of opportunity. There is also a cultural tendency to focus on medical interventions after birth — screenings, treatments, and diagnostics — while overlooking the upstream determinants of health.
A shift in perspective is needed. Pre-conception health should be seen as a core component of primary healthcare, integrated into existing programmes and delivered through routine health services. Public awareness must also improve, so that individuals recognise that their health today can shape the health of their future children.
The science is now clear — genes provide the blueprint, but the environment writes the story. The health of future generations is being shaped long before conception — in the choices, behaviour and conditions of those who will become parents. Investing in pre-conception health is not merely a clinical recommendation; it is a societal imperative with far-reaching benefits. It is one of the most powerful — and underutilised –tools that we have to build a healthier future.
Dr Chandrakant Lahariya is a practising cardio-metabolic physician, health policy expert and specialist in parenting and child development
