The first 1,000 days of life - from conception to two years of age - has been identified as a unique ‘window of opportunity' for nutrition, which can have a major long-term impact on health.

Speaking at a medical seminar on this topic in Dublin, Dr Emily Oken of Harvard Medical School in the US, who is an expert in this field, said that studies show that nutrition in early life ‘has a lifelong influence on the health of an individual'.

Her research has pinpointed the first trimester during pregnancy as the most sensitive period of development. At this stage, the baby is most sensitive to environmental exposures, such as poor nutrient intake and excess weight gain by the mother.

"The nutrition a baby receives in the womb during the first trimester in particular, has a lasting effect on their cognitive development and risk of obesity, type 2 diabetes, heart disease and stroke in later life," she commented.

Dr Oken is currently involved in an ongoing study into the benefits of maternal oily fish consumption on the cognitive development of offspring.

"Our research shows that moderate fish consumption during pregnancy showed no detrimental effects on the offspring and can actually benefit their language and visual motor skills in the early years of life," she explained.

Also speaking at the seminar, Prof Michael Turner, the national lead for the HSE clinical programme in obstetrics and gynaecology, pointed out that the increasing rate of obesity in Ireland ‘is having a severe impact on contemporary obstetrics'.

"We now know that a woman's pre-pregnancy weight is far more influential than weight gained during pregnancy on her offspring and contributes to her chance of gestational diabetes, incidents of which have increased in Ireland threefold in the last six years.

"This is largely due to the fact that one in six women in Ireland are obese before they conceive and there is better screening compliance among obstetricians and GP's. Gestational diabetes results in maternal and foetal complications and the need for obstetric intervention, all of which increase the cost," he explained.

Dr Oken and Prof Turner made their comments at the annual First 1000 Days seminar, in association with the Irish Nutrition and Dietetic Institute (INDI). It is part of a programme aimed at encouraging behavioural change in the way nutrition is approached in Ireland.

The seminar, which took place in Dublin's Convention Centre, was told that while the impact of good nutrition on children's physical and cognitive health is well acknowledged, expectant parents and new parents need more advice and support.

For more information on the importance of the first 1,000 days, click here or follow the movement on Twitter at @First1000Days.