RESUMEN
BACKGROUND: Data on analgesic effects of breast/formula milk sucking while receiving routine childhood immunizations are available only in early infancy, have rarely been compared in the same study, and are not accompanied by information on mothers' satisfaction/acceptance. Here we aimed to compare the analgesic effect of both methods vs. held-only controls up to 1 year of age, and verify mothers' satisfaction. METHODS: Two to 12 months children subjected to vaccine were allocated into three groups: breastfed, formula-fed, and held-only controls. A video recording was performed to analyze pain parameters: crying latency/duration and specific scales [FLACC (Face, Legs, Activity, Cry, and Consolability), NIPS (Neonatal Infant Pain Scale)]. After the procedure, mothers filled in a satisfaction questionnaire. RESULTS: One-hundred and sixty-two children were recruited: 54 breastfed, 35 formula fed, and 73 controls. Breastfed showed the longest crying latency, and together with formula fed, had the shortest duration and lowest pain scores. Most mothers appreciated not only the respective feeding-mediated pain mitigation method used, but also the simply-holding procedure. In all cases, they felt reassured, with an unexpected frequent underestimation of their child's pain during the shot. CONCLUSIONS: The analgesic effect of breastfeeding during vaccination extends also to children >6 months old, and is obtained by formula too. Embracing the child may help to reassure mothers. IMPACT: We confirmed the analgesic effect of breastfeeding during the vaccination procedures in early infancy. We show for the first time that this effect is extended also to children up to 1 year of age, and it may be obtained by formula feeding as well. Most mothers appreciated pain mitigation not only through feeding, but also the simply-holding procedure. In all cases, mothers felt reassured, with an unexpected frequent underestimation of their child' pain during the shot. The promotion of these easily feasible and well-accepted strategies should be further encouraged within health professionals during vaccination procedures.
