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Baby weight losses and weight gains

What is normal for breastfed babies?

The World Health Organization growth standards1 are the best reference for growth in the first 2 years as they reflect the growth of healthy breastfed babies.

The general guidelines for weight and growth measurements are:

  • a baby loses 5-10% of birth weight in the first week and regains this by 2 weeks2
  • birth weight is doubled by 4 months and tripled by 13 months in boys and 15 months in girls1

  • birth length increases 1.5 times in 12 months1
  • birth head circumference increases by about 11 cm in 12 months1

However, all babies grow differently and these are just general guidelines. If you are concerned about your baby's growth, contact your medical adviser for a thorough assessment of your baby's general health and wellbeing.


Baby weight losses – the early days

Normal weight loss

It is normal for babies to lose weight after they are born, no matter what or how they are fed. It is normal for breastfed babies to lose weight for the first 3 days after birth. Weight loss in newborns is expressed as a percentage of the birthweight. A maximum weight loss of 7-10% in the first week is considered normal.2

Exclusively breastfed babies are perfectly adapted to survive on the small volumes of colostrum they receive in the first few days. After this, their mothers begin to make large volumes of breastmilk which then provides all the fluids, energy and nutrients they need and they will regain their birthweight by 2 weeks after birth.3

Regardless of the percentage of weight loss, what’s most important is for health care providers to determine what the overall clinical picture of the breastfeeding mother and baby pair is. For example, there is a significant difference between a 2 day old baby who has lost 10% of his birthweight and who is sleepy and not latching well may need more support but a 2 day old baby who has lost 10% and is feeding frequently and well is more reassuring.


Epidurals and intravenous fluids

Fluids given to a mother intravenously (in a “drip”) during the birthing process (eg with induction of labour or an epidural) can be passed onto her foetus via the placenta. This may result in a baby being born with extra fluids on board which will get removed when he/she urinates. This may make it appear as though the baby has lost an excessive amount of weight.4,5More recent evidence indicates that when a typical amount of intravenous (IV) fluids are administered, there is negligible effect on the foetus weight and subsequent postnatal weight loss.6

Further research is needed to establish if higher amounts of IV fluids given to the mother in labour/birth are associated with excessive weight loss in healthy, term, exclusively-breastfed, newborn babies and if so under what circumstances. 

What is a Growth Chart or a Percentile Chart?

Growth charts are used to help follow and assess a baby's growth. Your baby's weight can be plotted against a weight-for-age growth chart. Historically, these charts have been compiled by measuring the weights of hundreds of different children at each age. The most common type of growth chart is a percentile chart where these hundreds of weights are then divided into 100 equal groups. These groups are then plotted on a graph or listed in a table.

If your baby record book does not contain the World Health Organization growth standards, you may like to print out and put them in your book. Importantly, the World Health Organization growth standards are based on healthy, exclusively breastfed babies from six countries across five continents. These more accurately show how a normal baby should grow. You can find the World Health Organization child growth standards percentile charts and tables here:







The simplified World Health Organization child growth percentile field tables, which are very easy to read, can be found at: Girls, Boys 


How do I read a Growth/Percentile Chart? 

It is the pattern of growth over time, rather than a single measurement or percentile, that is important.

The following example explains how you should read a percentile chart:

  • 3% of children will be below the 3rd percentile and 3% of children will be above the 97th percentile
  • 15% of children will be below the 15th percentile and 15% of children will be above the 85th percentile
  • 50% of children will be below the 50th percentile and 50% of children will be above the 50th percentile

The 50th percentile is an ‘average, ’not a pass. That is, 50% of the healthy population is below this line and 50% is above it.

If a baby's height or weight is 'off the chart' (above the 97th percentile or below the 3rd), there is a higher chance of something being wrong and it is wise to check with your medical adviser. In many cases though, all is well. Three in every 100 normal babies will weigh less than the 3rd percentile, often because both parents are small.

Does it matter if my baby doesn't 'stick' to a percentile line?

Usually, no. Percentile charts are derived from the averaged measurements of hundreds of babies and so they show “smoothed” growth curves, which individual children shouldn't be expected to follow exactly. They can and do grow faster or slower at times.

It is not uncommon for a baby’s weight-for-age to cross percentile lines over the course of the first 6 months.  A large study in the US found that most babies (77%) crossed weight-for-age percentile lines in the first 6 months, with 39% of babies either moving up or moving down two percentile lines. From birth to 6 months, larger babies tended to put on weight more slowly (on average) and smaller babies put on weight more quickly. This may be because birth size relates more to nutritional conditions in the womb than to genetic potential for growth. As this group of children got older, they were much less likely to cross two weight-for-age percentile lines, but it did still happen.7 See Table 1 for more detail.

However, if a baby has persistent low weight gains with a pattern of weight gain indicating dropping percentiles at a faster rate than expected, it’s important to seek medical advise.

Table 1.


Percentage of infants and children crossing 2 percentile lines – weight-for-age

Percentage of infants and children crossing 2 percentile lines – weight-for-height

Birth to 6 months



6 to 24 months



24 to 60 months



My baby has had persistently low weight gains. Is my baby getting enough breastmilk?

Many mums who are worried that their baby is not gaining enough weight are also worried that their baby is not getting enough breastmilk.

These are some reliable signs of adequate milk intake.

Remember - what goes in must come out!:

  • After 5 days of age a minimum of 5 heavily wet disposable, or 6-8 very wet cloth nappies, in 24 hours.

  • Pale urine (wee). If your baby's urine is dark and smelly, this is a sign that your baby is not taking in enough milk.

  • Good-sized, soft poos. Under the age of 6-8 weeks, your baby should have three or more runny poos a day, about the size of the palm of your baby's hand. After this age, it can be quite normal for a baby to poo less often, even once every 7-10 days, as long as when your baby does a poo, there is a large amount of soft or runny poo coming out!

In addition to the 'what goes in must come out' signs above, other reliable signs that result from an adequate milk intake in a healthy baby are:

  • Baby has some weight gain after the initial weight loss soon after birth, and some growth in length and head circumference. (Are your baby's clothes getting snugger?)
  • Baby looks like she fits in her skin - with good skin colour and muscle tone.
  • Baby is meeting developmental milestones.

For more information about how to tell if your baby is getting enough milk, refer to the article Low Supply on this website.

My baby is getting enough breastmilk. What's causing the low weight gains?

If your baby appears to be underweight, with wrinkly, loose skin and yet has a good nappy count indicating enough milk intake, it may be that your baby has an underlying medical condition which is causing a slow weight gain. There are many conditions which could affect weight gain. Some of the common ones include:

  • infection (anything from a cold to a urinary infection)
  • vomiting or frequent posseting (eg pyloric stenosis or severe reflux) - can mean a baby does not retain enough milk to grow
  • a severe allergy to foods in the mother's diet could be a cause of low weight gain.

Your medical advisor will be able to help you investigate these and other areas.

My baby is getting enough breastmilk. Is my baby just meant to be small?

Some adults are naturally petite and so are some babies. If your baby appears to be happy and healthy, is meeting developmental milestones, does not appear underweight (does not have loose wrinkly skin) and has a good wet/pooy nappy count, then your baby's low weight gains may be due to family factors (genetics).

I think my baby is NOT getting enough breastmilk. What can I do?

  • Is your baby feeding often enough? The simplest and most effective way to increase your baby's milk intake is to breastfeed more often. Babies need at least 6 feeds in 24 hours in the first few months. For most babies, 6 will not be enough; they need 8-12 feeds in 24 hours (or more) to take in enough milk.
  • More frequent feeding also means your breasts are relatively 'emptier' (they are never completely empty), which means that your breasts will speed up milk production, increasing your milk supply. For more information on how to increase your milk supply refer to the article Low Supply on this website, or refer to the Australian Breastfeeding Association booklet, Increasing Your Supply, available for purchase from the Australian Breastfeeding Association.
  • Is your baby feeding according to his or her individual need? This helps ensure your baby receives the breastmilk he or she needs.
  • Have you only been offering one breast per feed? Some babies only need one breast per feed, other babies need both. Some babies start off just needing one and change as they grow older. You could try offering your baby the second breast.
  • Try offering top-up breastfeeds after your baby's normal breastfeeds.
  • Is your baby sleeping longer at night? Long night sleeps (and therefore missed feeds) can also decrease your baby's milk intake and weight gain. You might consider waking your baby during the night to feed or fit in extra daytime feeds.
  • Is your baby attaching and suckling effectively? Babies who are failing to thrive may have a poor sucking action, so they don't empty and stimulate your breasts enough. Face-to-face assessment of this by an International Board Certified Lactation Consultant (IBCLC) or Australian Breastfeeding Association counsellor can be very useful. You can find an IBCLC near you at this website: Find a Lactation Consultant.
  • Does your baby have a tongue-tie? Some babies with an anterior tongue tie may not be able to remove milk as well from the breast.8 Seeing an IBCLC can help work out what might be going on and refer onto an appropriate health professional (eg medical professional, paediatric dentist) who can make the diagnosis and release the tongue-tie, if necessary. 
  • Have you been using a nipple shield? Provided a nipple shield is used properly, it should not cause supply problems. However, if your baby's weight gains continue to be low, it could be that your baby is not transferring milk well through the shield. Consult a lactation consultant or an Australian Breastfeeding Association counsellor to check that your baby is attached properly on the shield and the correct size nipple shield is being used.

What are developmental milestones?

Developmental milestones are normal skills and abilities that babies and children acquire as they grow. These include events such as smiling for the first time, turning their head towards a sound, bringing their hand to their mouth, holding their head steadily without support, rolling from tummy to back and taking a first step.

Developmental milestones tend to appear in a predictable order and the this link takes you to information about what kind of milestones to expect at each age.

My baby was gaining weight well and now all of a sudden things have slowed down. What's going on?

  • Have there been any changes in your baby's behaviour? For example has your baby been taking fewer feeds as a result of sleeping longer at night?
  • Have you been trying to feed at set times instead of when the baby indicates?
  • Have you (the mother) been stressed or unwell? For some women this can cause a temporary dip in supply.
  • Have you just started a new medication such as the contraceptive pill? Could you be pregnant? These factors can cause a dip in your supply.
  • Has your baby been ill? Even a small cold can disrupt feeding and weight gain for a week or two.
  • Has your baby previously gained well and is now slowing down normally? It is very normal for an exclusively breastfed baby's weight gain to slow down at 3-4 months. The World Health Organization child growth standards, based on healthy breastfed babies, help demonstrate this.

In most cases of sudden weight change, a 'wait-and-see' approach is justified if your baby seems happy and the other indicators of growth and health are fine. If there seems to be a temporary low supply problem, offering a couple of extra breastfeeds a day can help avoid a more serious situation. If you are concerned, see a medical advisor.


1.     WHO Multicentre Growth Reference Study Group. (2006). WHO Child Growth Standards based on length/height, weight and age. Acta Paediatrica (Oslo, Norway: 1992). Supplement, 450, 76-85.

2.     Noel-Weiss, J., Courant, G., Woodend, A.K. (2008). Physiological weight loss in the breastfed neonate: a systematic review. Open Med 2(4), e99–e110.

Bertini, G., Breschi, R., Dani, C. (2015).Physiological weight loss chart helps to identify high-risk infants who need breastfeeding support. Acta Paediatr 104(10), 1024-1027

Grossman, X., Chaudhuri, J.H., Feldman-Winter, L., Merewood, A.(2012).Neonatal weight loss at a US Baby-Friendly Hospital. J Acad Nutr Diet 112(3), 410-413.

3.     Macdonald, P. D., Ross, S. R. M., Grant, L., & Young, D. (2003). Neonatal weight loss in breast and formula fed infants. Archives of Disease in Childhood-Fetal and Neonatal Edition, 88(6), F472-F476.Noel-Weiss, J., Courant, G., Woodend, A.K. (2008). Physiological weight loss in the breastfed neonate: a systematic review. Open Med, 2(4), e99-e110.

Bertini, G., Breschi, R., Dani, C. (2015).Physiological weight loss chart helps to identify high-risk infants who need breastfeeding support. Acta Paediatr 104(10), 1024-1027

Grossman, X., Chaudhuri, J.H., Feldman-Winter, L., Merewood, A.(2012).Neonatal weight loss at a US Baby-Friendly Hospital.J Acad Nutr Diet 112(3), 410-413.

4.     Noel-Weiss, J., Woodend, A.K., Peterson, W.E., Gibb, W., & Groll, D.L. (2011). An observational study of associations among maternal fluids during parturition, neonatal output, and breastfed newborn weight loss. International Breastfeeding Journal 6: 9.

5.     Watson, J., Hodnett, E., Armson, B.A., Davies, B., Watt-Watson, J. (2012). A randomized controlled trial of the effect of intrapartum intravenous fluid management on breastfed newborn weight loss. JOGNN 41: 24–32.

Hirth, R., Weitkamp, T., Dwivedi, A. (2012). Maternal intravenous fluids and infant weight. Clinical Lactation 3: 59–93.

6.     Eltonsy, S., Blinn, A., Sonier, B., DeRoche, S., Mulaja, A., Hynes, W., Barrieau, A., Belanger, M. (2017). Intrapartum intravenous fluids for caesarean delivery and newborn weight loss: a retrospective cohort study.BMJ Paediatr Open 1(1), e000070

7.     Mei, Z., Grummer-Strawn, L. M., Thompson, D., & Dietz, W. H. (2004). Shifts in percentiles of growth during early childhood: analysis of longitudinal data from the California Child Health and Development Study. Pediatrics, 113(6), e617-e627.

8.     Geddes, D.T., Langton, D.B., Gollow, I., Jacobs, L.A., Hartmann, P.E., Simmer, K. (2008). Frenulotomy for breastfeeding infants with ankyloglossia: effect on milk removal and sucking mechanism as imaged by ultrasound. Pediatrics 122(1), e188-94.

© Australian Breastfeeding Association January 2019





Last reviewed: 
Jan 2019