Ideally weigh infants completely naked and ideally on the same scale. It is normal for an infant to lose weight during the first few days after birth. The infant weight loss will level off around day three to four when mom’s milk increases in volume¹. It is important to have a weight done on the day of hospital discharge, in order to determine the change in weight at the first outpatient visit. An infant who is feeding effectively should lose no more than 7 – 10 % of birthweight. An infant who has lost more than 7% of birthweight during the hospital stay should be evaluated by a lactation specialist to assess feeding effectiveness as a means of preventing excessive weight loss². There is evidence that excessive intravenous fluids given to mothers in labor will exaggerate newborn weight loss in the first few days postpartum³. Therefore, it is important to monitor the cadence of weight loss each day. As colostrum is increasing each day postpartum the rate of % weight loss should decline. Infants who are at or near a 10% weight loss at hospital discharge need a feeding plan to prevent further weight loss², since greater than 10% weight loss increases the risk of infant hypernatremia, which can have neurologic consequences.

Many physicians who care for newborns use the ‘Newborn Weight Tool’ at newbornweight.org¹. This is a general guide to help determine if the trend of weight loss for an individual newborn is average or excessive. This information can be one tool to help determine when to supplement. See information below on ‘Indications for Supplementation.’