Average Newborn Weight

It seems some of the most common questions parents hear from the moment a new baby arrives is “what does the baby weigh?” and “how is the baby growing?” The weight of a newborn is often used as a marker of general health, so it makes sense that it is something everyone is monitoring. But how does a parent know if their child is gaining weight at a healthy rate?
There are some general guidelines parents can look at to help keep an eye on their baby’s progress.

How to Monitor Your Baby’s Growth

Most babies who are born full-term (38-40 weeks gestation) weigh between 6-9 lbs. Birth weight can be affected by many factors, such as pregnancy gestation at birth ( whether earlier or later than “full term”), baby’s gender, mother’s health during the pregnancy, parents’ build, nutrition during pregnancy, multiples birth, or baby’s health at birth.
Babies can be born outside of the average guidelines and still be completely healthy. It is expected that newborns will lose some weight in the first 5-7 days of life. A 5% weight loss is considered normal for a formula-fed newborn. A 7-10% loss is considered normal for breastfed babies.
Most babies should regain this lost weight by days 10-14 of life. If a baby loses a significant amount of weight, is sick, or is premature, it may take up to 3 weeks to get back to his or her birth weight.

Formula-Fed and Breastfed Differences

Most newborns will gain about 5-7 oz a week for the first few months. Many babies will have doubled their birth weight by about 3-4 months. At 4 months, weight gain will begin to look different for breastfed and formula-fed babies. Research clearly shows that breastfed babies and formula-fed babies grow at different rates starting at about 4 months of age.
However, most growth charts are based only on formula-fed babies’ growth, which leads many breastfeeding moms wondering if their baby is “normal.” The World Health Organization (WHO) has worked to develop new growth charts based on breastfed babies, but not all physicians are using these when making their assessment.
Make sure your physician is clear on what feeding method you are using so the correct chart is used to assess your baby’s weight gain. For more information, see the WHO Growth Charts for Infant Boys and the WHO Growth Charts for Infant Girls.

Your Newborn’s Weight Gain

Newborns are often weighed throughout their stay in the hospital and sometimes again 48-72 hours after discharge. Newborns are then weighed a week after birth and sometimes again at two weeks after birth. If a baby has any health concerns, weight checks may be scheduled more frequently.
If parents don’t have a scale at home, they can monitor their baby’s intake of food in other ways:

  • After the first week, a newborn should be having at least 5-7 wet diapers a day and at least about 3-4 dirty diapers a day. (This may change with time, and formula-fed babies seem to have fewer bowel movements than breastfed babies.)
  • You can also monitor your baby’s intake by noticing if your baby seems satisfied at least for a little while after feeding. (Keep in mind that some babies do seem to want to eat all the time!)

If you have any questions or concerns regarding your baby’s weight gain, don’t hesitate to ask your health care provider.

Compiled using information from the following sources:
The Nemours Foundation, https://kidshealth.org/
World Health Organization, https://www.who.int/
KellyMom Breastfeeding and Parenting, https://www.kellymom.com/
Ask Dr. Sears.com, https://www.askdrsears.com/