Parental diet affects baby’s health years before conception

Parents’ diets and health can have profound implications for the growth, development, and long-term health of their children before their conception.

Parents’ diets and health can have profound implications for the growth, development, and long-term health of their children before their conception, according to a series of three papers published in The Lancet

The series authors, including Professor Janet Cade and Dr Jayne Hutchinson from the University of Leeds, draw on existing evidence from around the world to redefine the preconception period and outline how preconception risk factors affect unborn babies and lifelong health risks. They also proposes interventions to help improve preconception health that span the lifetime.

To help improve health in future generations, the authors call for a joint focus, including better guidance and support for individuals planning pregnancy, and increased public health measures to reduce obesity and improve nutrition. 

The papers present two new analyses of the diets and health of women of reproductive age (18-42 years old) in the UK and Australia. 

Series co-author, Janet Cade, Professor of Nutritional Epidemiology and Public Health at Leeds, said: “Healthy diet and nutrition are an important part of care in pregnancy, but our work shows that many non-pregnant women may not be best prepared nutritionally for pregnancy with low intakes of fruit and vegetables, some key vitamins and minerals and high rates of overweight/obesity.  

“Improved support and practical tools are needed to help people understand how, even before a woman becomes pregnant that parental lifestyle including weight and diet can influence the health of their children.”

Defining the preconception period

Previous research has defined the preconception period as three months before conception, as this is the average time it takes for fertile couples to become pregnant. 

But this is imprecise, and ignores the time taken to achieve preconception health improvements – with some taking less than a month, such as achieving adequate folic acid levels, and others taking months or years, such as achieving a healthy weight. 

Taking this into account, the series authors redefine the preconception period biologically – as the days to weeks before and after fertilisation; individually – as the weeks or months when a woman or couple decides to have a child; and at a public health level – as the months or years needed to address preconception risk factors, such as diet and obesity, before pregnancy. 

Preconception health risk factors

Evidence suggests that smoking, high alcohol and caffeine intake, diet, obesity and malnutrition potentially cause genetic, cellular, metabolic and physiological changes during the development of the unborn baby, which have lasting consequences into adulthood and increase the child’s lifelong risk of cardiovascular, metabolic, immune, and neurological diseases. 

In particular, maternal obesity, which is also linked to poorer birth outcomes, is thought to increase levels of inflammation, hormones and metabolites, which may directly alter the development of the egg and embryo to increase the risk of chronic disease in later life. 

Male obesity is also important, and is associated with poor sperm quality, quantity and motility, which could increase the risk of chronic disease in later life. However, it is uncertain whether paternal diet and obesity have as strong an influence as maternal preconception health. 

It is noted that there could be more risk factors associated that have not yet been identified. 

In a new analysis, the proportion of women of reproductive age—18-42 years old—in the UK who are nutritionally prepared for pregnancy was calculated using data from 509 women of reproductive age in the UK National Diet and Nutrition Survey. 

The analysis suggests that many UK women are not nutritionally prepared for pregnancy, and almost all women of reproductive age—roughly 96%—have iron and folate dietary intakes below the recommendation for pregnancy. 

Series co-author Dr Hutchinson, from the School Food Science and Nutrition, said: “Looking at the current state of health of many UK women, our work suggests that interventions need to start years before pregnancy. Improving everyone’s health from an early age will not only help reinforce proper diet and nutrition for those planning for children, it could be particularly beneficial to those who may have unplanned pregnancies.” 

Improving preconception health

The authors recommend interventions that span a lifetime. They say that these interventions should understand and harness people’s reasons to engage with preconception health at different stages in their lives to support people to change. 

Starting in adolescence, schools need to help young adults prepare for parenthood in the future. Support for improving nutrition before conception needs to be offered in ways that engage adolescents in thinking about their diets and health, and the implications of this in later life, in pregnancy, and for future generations. 

Building on this, in adults with no immediate plans to become pregnant, they call for social change that supports improved public awareness of preconception health. Lastly, in adults planning to become pregnant, they call for improved support and practical tools for preconception health.

The authors also suggest that the food industry and food retailers should be part of the solution, working alongside government organisations, non-governmental organisations, and research institutions to form advocacy coalitions to create more demand for preconception health support.

Further information 

The paper series are available in the Lancet, www.thelancet.com/series/preconception-health

Please contact University of Leeds Media Relations Officer Anna Harrison via a.harrison@leeds.ac.uk or +44(0)113 343 4196 for additional information.