Dr. Kristie Rivers is an Attending Physician, Assistant Medical Director of the Pediatric Hospitalist Program, and Director of Pediatric Medical Education at a children’s hospital in Fort Lauderdale, Florida.
At 3 weeks old, your babies are already starting to show you what they want by how they cry. At this age, you and your newborn are in a bit of a routine, even if you’re still learning when they want to eat. From spitting up to the start of colic, Dr. Kristie Rivers answers some major feeding questions that parents have when week 3 comes around.
Bundoo: What should a parent of a 3-week-old expect in terms of eating? About how much will a baby eat at every feeding?
Dr. Kristie Rivers: By three weeks of age, your baby is growing and changing every day, including his or her appetite. If your baby is breastfed, he or she will still eat every 2-3 hours, nursing at least 15-20 minutes at a time. You may notice that your baby cluster feeds at times, meaning he or she eats more frequently, then goes for longer periods of time between feeds. A formula-fed baby can go a little longer between feeds, usually eating every 3-4 hours. Most formula-fed babies at 3 weeks eat around 3-4 ounces at a time.
What do you look for in a healthy 3-week-old in terms of growth and development? Is there anything parents should know about growth rates?
At three weeks of age, your baby should be well over his or her birth weight. In fact, it is normal for babies at this age to gain 20-30 grams (2/3 of an ounce) per day. In addition to weight, your baby’s doctor will also look at the size of the head and plot it on the growth chart to makes sure the brain is developing normally. The average baby’s head grows about 3 cm in the first few weeks of life.
As babies eat more, many begin to spit up. What is spit up exactly, and is this something parents should worry about? Can they do anything about it?
Spit ups are very common in infants. Sometimes the muscle at the bottom of the esophagus is not tight in babies, leading to the milk coming back up after a feed. Other times, the baby is being overfed, so the stomach is filled up too much, and the milk has nowhere to go but back up. If your baby is gaining weight appropriately and doesn’t seem overly fussy, the spit up is nothing to worry about. However, if your baby is spitting up so much milk that he or she is not gaining the appropriate amount of weight or seems to be in pain during eating, he or she should be evaluated by the pediatrician.
Babies cry a lot at 3 weeks, but this is also right around the time colic starts. How will parents know if their baby has colic, as opposed to just regular crying?
Babies at this age cry for a variety of reasons, including hunger, sleepiness, discomfort from a wet/dirty diaper, or pain. However, once the problem is taken care of, many babies will settle. If your baby has bouts of crying lasting more than 3 hours a day with no obvious reason, this is likely due to colic. Babies with colic often have predictable periods of crying throughout the day and are often content at other times. As long as your baby is growing well and has a normal physical exam, you can be reassured that this fussy period will end at around three to four months of age.