Redefining the preconception period

In a series of papers Professor Poston, Head of King’s School of Life Course Sciences, and colleagues from University college of London and the University of Southampton draw on existing evidence to demonstrate that preparing for conception is an excellent way of preventing disease. In a major step towards understanding the life course of health, the authors redefine the preconception period, outline how parental lifestyle and diet affect unborn babies and propose interventions to improve health prior to conception.

Previous research has defined the preconception period as the three months before pregnancy as this is the average time it takes for fertile couples to conceive. This is imprecise, however, and ignores the time it can take to improve parental health.

Professor Poston and her colleagues, therefore, redefine this 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 risk factors like diet and obesity.

Although there are short-term changes that individuals can make, such as ensuring adequate levels of dietary iron and folate, it can take much longer to lose weight, for example. Estimates also suggest that as many as 40 per cent of global pregnancies are unplanned and so efforts to improve nutrition and health at a population level are needed to support those made by parents planning for pregnancy.

Speaking of the findings Professor Poston says, "This is a ground-breaking series of papers on preconception health. In recent months there has been growing interest and a new focus on the health of women and their partners before pregnancy. This series shows that changes in diet, exercise and general health at this time can have an impact on both mother and baby."