I'm fully breastfeeding but my newborn lost weight. Is this normal?
It is very normal for your baby to drop down a few ounces after birth. Your baby was born with excess fluid to aid in a smooth journey through the birth canal. If you received fluids during labor, this could cause higher amounts of fluid in your baby. Within 24-48 hours after birth, most of this fluid will go away. This is why the 24-hour weight is more accurate to use when determining the percentage of weight loss. Your baby should be back up to their 24-hour weight by two weeks of age.
Usually colostrum is all that is needed until the milk "comes in". Keep offering your breast when you see your baby having early hunger cues, even at night, and wake a sleepy baby to nurse. In some cases, it may take a little longer for the mature milk to come in. For additional breast stimulation, do some hand expression between feedings and give the extra colostrum to baby in a syringe or teaspoon (so they don't develop a preference to a bottle).
Once your mature milk comes in, baby will start to feed more frequently and for longer periods of time. This will help their weight gradually increase. If your baby is still at or under the 24-hour weight by two weeks, consider speaking with your doctor.