Trends in social inequality in breastfeeding duration in Denmark 2002-2019

Aims: The aim of the present study was to analyse trends in full breastfeeding for at least 4 months across socioeconomic position in Denmark over a 17-year-long period from 2002 to 2019 using parental education as the indicator of socioeconomic position.Methods: The study used data on full breastfeeding collected between 2002 and 2019 by community health nurses in the collaboration Child Health Database, n=143,075. Data were linked with five categories of parental education from population registers. Social inequality was calculated as both the relative (odds ratio) and absolute social inequality (slope index of inequality). A trend test was conducted to assess changes in social inequality over time.Results: A social gradient in full breastfeeding was found for the entire study period. The odds ratio for not being fully breastfed for at least 4 months ranged from 3.30 (95% confidence interval 2.83-3.84) to 5.09 (95% confidence interval 4.28-6.06) during the study period for infants of parents with the lowest level of education (primary school) compared with infants of parents with the highest level of education (5+ years of university education). The slope index of inequality was between -38.86 and -48.81 during the entire study period, P=0.80. This indicated that both the relative and absolute social inequality in full breastfeeding to at least 4 months of age was unchanged in the study period from 2002 to 2019.Conclusions: This study showed a persistent relative and absolute social inequality in full breastfeeding for at least 4 months from 2002 to 2019 in Denmark.