Risk factors for and protective factors against breastfeeding interruption before 2 years: a birth cohort study

Abstract

Background Little is known about the factors associated with the World Health Organization (WHO) recommendation of breastfeeding for at least 2 years. The objective of this study was to identify risk factors for and protective factors against breastfeeding interruption before 2 years of age. Methods In this live birth cohort, mother and infant dyads were followed for 2 years. Data collection was performed at the maternity ward and subsequently at the children’s homes, monthly during the first 6 months of life and then at 9, 12, 18, and 24 months. The outcome of interest was breastfeeding interruption before 2 years of age. Median duration of breastfeeding was estimated using Kaplan-Meier’s survival analysis, and the associations were tested using Cox’s hierarchical multivariate model. Significance was set at 5%. Results Data from a total of 1344 dyads were assessed. Median breastfeeding duration was 385 days. The following risk factors for breastfeeding interruption were identified: white skin color (adjusted hazard ratio [HRa]: 1.31; 95% confidence interval [95%CI]: 1.10–1.56), primiparity (HRa: 1.21; 95%CI: 1.05–1.40), working outside the home (HRa: 1.52; 95%CI: 1.30–1.77), child sex male (HRa: 1.18; 95%CI: 1.03–1.35) and use of a pacifier (HRa: 3.46; 95%CI: 2.98–4.01). Conversely, the following protective factors were identified: lower family income (HRa: 0.81; 95%CI: 0.71–0.94), mother-infant bed-sharing (HRa:0.61, 95%CI: 0.52–0.73), on-demand breastfeeding in the first month (HRa: 0.64; 95%CI: 0.47–0.89) and exclusive breastfeeding at 4 months (HRa: 0.58, 95%CI: 0.48–0.70). Conclusions The findings allowed to identify both risk factors for and protective factors against breastfeeding interruption before 2 years of age. Knowledge of these factors may help prevent this event and aid in the development of programs that help women maintain breastfeeding for at least 2 years, as recommended by the WHO.

Prevalence and predictors of breastfeeding in the MINA-Brazil cohort

“…As for the child's sex, earlier BF cessation was more frequent among boys, with similar findings being described among Brazilian 15 , 27 and US Hispanic 28 populations. Sociocultural norms and perceptions about higher nutritional needs among male than female children, together with traditional gender views 28 , may influence parents’ decisions regarding BF duration.…”

“…Pacifier use in the first week of life incurred in a risk 1.79 and 4.66 times higher, respectively, for EBF and BF cessation before recommended, showing that its negative effect extends beyond early life 8 . Despite previous evidence relating the use of pacifier to shorter EBF 14 and BF duration 15 , the literature is conflicting 25 . Recently, the WHO revised the Baby-Friendly Hospital Initiative's Ten Steps to Successful Breastfeeding, updating step 9 to counsel mothers on the use and risks of feeding bottles, teats and pacifiers instead of entirely prohibiting them for term infants, enabling families to make informed decisions about using or avoiding artificial nipples until breastfeeding is successfully established.…”

“…Lastly, children who were exclusively breastfed for less than 3 months had a 2.7-fold greater risk of shorter BF duration. Some Brazilian 15 , 29 and international 30 research has pointed out the association between longer EBF and longer BF duration. Estimates from a cohort study of mother-child pairs conducted in Porto Alegre, Brazil, showed that the probability of BF maintenance up to 2 years of age or more was 0.5% and 0.1% greater for each extra day of preventing the infant's exposure to water or tea and other kinds of milk, respectively 29 .…”

“…Environmental and motivational factors that predispose exclusive breastfeeding may favor continued breastfeeding in subsequent weeks 30 . Moreover, mothers who offer liquids or food in addition to breast milk may experience lower milk production due to reduced feedings and less nipple stimulation 15 , 30 .…”

“…Statistical significance was set at p < 0.05. The selection of exposures followed conceptual hierarchical models of factors associated with EBF 14 and BF 15 at four levels of determination: distal (socio-economic and demographic factors), distal-intermediate (obstetric factors), intermediate-proximal (perinatal characteristics) and proximal (mother-child characteristics in early life). Distal estimates were adjusted for all variables at that level of determination; those associated with the outcome were retained for model adjustment at the subsequent levels.…”