[Maternal leave extension effect on breastfeeding according to poverty, Chile 2008-2018].

Introduction: In Chile in 2011, the postnatal leave was extended from 12 to 24 weeks.

Objective: To determine the effects of the extension of maternity leave on the prevalence of breastfeeding in Chile according to poverty groups.

Methods: Ecological study on the annual prevalence of exclusive breastfeeding at 1st month (EBF1m) and 6th month (EBF6m), and supplemented at 12th month (BF12m) in the public health system between 2008 and 2018, based on the monthly statistical records of primary care. The prevalence was calculated nationally and by region groups according to the poverty level reported by the National Socioeconomic Characterization Survey (CASEN). The variation in the time trend was determined through segmented Poisson regression models (joinpoint), estimating the Annual Percentage Change (APC).

Results: Nationally, since 2011, the prevalence of EBF6m and BF12m increased annually by 5.9% and 4.2%, reaching 58.9% and 40.2% in 2018, respectively. This pattern is repeated in the different regional poverty groups, showing a higher prevalence in the poorest group, reaching 61.7% at EBF6m and 51.6% at BF12m in 2018. The EBF1m decreased annually by 1.7% between 2008 and 2014 and then remained without changes, reaching 74.7% in 2018.

Conclusions: The EBF6m prevalence increased significantly since 2011 due to the extension of the maternity leave. This effect occurs in all regional groups of poverty, narrowing the differen ces in prevalence.