Abstract

The healthy newborn (NB) experiences physiological weight loss in her/his first days of life. Identi-fying normal weight loss in this period is relevant since it allows the clinician to make decisions in relation to the need to supplement breastfeeding. Objectives: To determine the curves that graph the weight loss experienced by healthy newborns exclusively breastfed during the first 48 hours after birth. Patients and Method: Retrospective and analytical descriptive study in healthy full-term NBs during their stay in the nursery, exclusively breastfed, and with mixed feeding. Weights were recor-ded at birth and on the first and second day of life. A quadratic polynomial was used to model the relative weights. The percentiles of the variations in weight loss were estimated. Results: The sample consists of 4331 NBs with an average gestational age of 38.84 weeks. Of these, 56.45% were vaginal deliveries and 43.55% cesarean sections. The distribution by sex was 49.37% male and 50.63% fema-le. Regarding adequacy, 82.96% were adequate for gestational age, 6.33% were small for gestational age, and 10.71% were large for gestational age. The greatest weight loss was observed in the first 12 hours of life. Conclusions: A weight loss graph is obtained for the first 48 hours of life, representing the weight loss per hour for healthy term NB exclusively breastfed. These curves can be used as a decision-making tool to categorize the weight loss of the NB and help in decision making regarding the indication to add artificial feeding.