Neonates tend to lose weight transiently during the first few days of life after which weight gain occurs. Flaherman reported curves correlating weight loss at a given time with the population norms. The authors are from the University of California San Francisco, Penn State College of Medicine and Kaiser Permanente in Oakland.

Patient selection: neonate delivered vaginally, age range 6 to 72 hours, exclusively breastfed



(1) number of hours since birth

(2) birth weight

(3) current weight


weight loss =

= ((current weight) - (birthweight))/(birthweight)


curve for 75th percentile of weight loss =

= (0.002115 * ((hours)^2)) - (0.2794 * (hours)) + 0.3227


curve for 95th percentile of weight loss =

= (0.001682 * ((hours)^2)) - (0.2646 * (hours)) - 1.002


Less than 5 percent of neonates will show a greater weight loss than indicated by the 95th percentile curve.

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