Yes! Weight loss in the first three days after birth is normal for healthy full term babies.
This weight loss is due to the mismatch between calorie demands of the newborn and milk production by the mother. In an exclusively breastfed infant, doctors monitor this weight loss to ensure it does not dip below a 7 percent loss compared to birth weight. If so, they work with the mom to make sure milk production and the transfer of milk to the newborn are appropriate. A newborn who nurses well will begin to regain this weight on day four or five of life and should be back up to birth weight by 10-14 days of life.
Early weight loss and early breastfeeding challenges are two of the reasons that doctors would like to see newborns in their office two days after discharge from the hospital or birthing center. In a healthy baby who has not lost more than 7 percent of their birth weight, formula supplementation is not necessary.