Objectives To estimate the prevalence of cessation of exclusive breast feeding at each month up to 6 months and document key factors and cumulative risks associated with exclusive breastfeeding cessation for children aged from 0 to 6 months.

Methods Secondary analysis using a national representative sample of 22 202 mother and infant pairs derived from the 2010 Australian Institute of Health and Welfare cross-sectional survey, the Australian Infant Feeding Survey.

Results Among breastfed infants, 49% had ceased exclusive breast feeding before they had reached 2 months of age. In the final Cox proportional hazards model, cessation of exclusive breast feeding was most strongly associated with partners preferring bottle feeding (HR 1.86, 95% CI 1.69 to 20.6) or having no preference (HR 1.37, 95% CI 1.33 to 1.42), regular dummy use (HR 1.35, 95% CI 1.31 to 1.39) and maternal obesity (HR 1.29, 95% CI 1.24 to 1.35). Living within the most disadvantaged areas of Australia (quintile 1) was not strongly associated with cessation (HR 1.08, 95% CI 1.02 to 1.14) compared with least disadvantaged areas. Having three risk factors significantly increased the risk of cessation by 31% (HR 1.31, 95% CI 1.07 to 1.6).

Conclusions The prevalence of early cessation of exclusive breast feeding is alarmingly high with 50% of infants no longer exclusively breast fed by age 2 months. Given that not one factor is associated with cessation of exclusive breast feeding, the greatest public health impact is likely to be achieved when multiple risk factors are modified or prevented.