The influence of birthweight and breastfeeding status on BMI outcome at first year of primary school: a retrospective study of an Irish child cohort.

• This study investigated whether there was an association between sex, birthweight and breastfeeding status and the BMI outcome of a cohort of Irish children in their first year of primary school education (median age: 5.2 years). • This study also included an exploration of parents concern related to their child's growth at first year of primary school education.