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How much do babies feed?


It’s 5 pm on a Thursday afternoon. Amongst the babes with bronchiolitis, kids with possible COVID and adolescents with abdominal pain, I’ve seen at least three fussy infants today with feeding problems. Each of them was feeding fine, and time spent with the little one’s parents to really hear their worries was all it took. Infant feeding is stressful. In a COVID-riddled world with reduced access to health visitors and primary care physicians, reduced access to baby groups and reduced time spent with grandparents, this stress can become all-encompassing. As ED clinicians, our role is to understand what’s normal and what’s not and know when to reassure and when to investigate. Taking a good infant feeding history is key.

There are three key areas to a feeding history: the ins – feeding and weight gain – and the outs – peeing, pooing and vomiting, and the parents – are they ok?

The ins:

Let’s start with some questions about feeding

How much does the baby feed? And how often do they feed?

Volumes are easy to quantify in bottle-fed babies – after the first few days of life, babies should take about 150 ml/kg/day from day 4 or 5 of life until the infant is a few months old. In the breastfed baby, the first few days of feed are colostrum – thick, fat-enriched milk – and volumes are small. As a breastfeeding mother’s milk comes in, usually around day 4 or 5 of life, the volume of milk a neonate can take will increase. I use analogies to help explain this to parents.

On day 1 of life, a neonate’s stomach is only the size of a cherry – it can only really hold about 5 millilitres of milk, a teaspoon.

By day 3, it’s increased to the size of a walnut, which is still only 30 millilitres or 1 ounce.

By a week, it’s the size of an apricot and can hold 60 millilitres, or 2 ounces.

And by a month, it’s the size of an egg and can hold 150 millilitres, 5 ounces.

Some babies take a little more, sometimes up to about 180ml/kg/day. As long as the baby is happy with normal poos, no excessive vomiting and no excessive weight gain, this is fine. Sometimes, bigger volumes can be a little too much for tiny infant stomachs, and dropping the volume down a little can help with overfeeding-related problems.

Quantifying volumes in breastfed babies is harder, but good questions to ask include:

How long the baby does the baby feed with a good suck? And do your breasts feel like they’re emptying?

Most infants will actively suck for 10 to 30 minutes per feed. Lots will take little naps and not really suck – I don’t count this as feeding time, more like snuggling time. Ask about the frequency of feeds, but understand that this can vary. Some babies take easily to a routine with feeds every 3 to 4 hours, others, particularly breastfed babies, may feed more frequently, every 1 to 2 hours. And there’s nothing wrong with this – each baby and their parents will find a way that works for them.

Spend some time exploring the baby’s weight gain

It’s normal – and expected – for a neonate to lose about 10% of their birth weight in the first few days of life. They have tiny stomachs, with small volumes of milk and a large amount of fluid shift in the immediate postnatal period. As long as their weight loss doesn’t significantly exceed this and the neonate is back to their birth weight by two weeks of age, this isn’t something to worry about.

Good weight gain is about 150 – 200 grams a week in the first three months of life. A wise neonatologist once told me, “Weight gain should be 30g a day, except on Sundays.”

As infants become more active, weight gain slows a little. Between three and six months, we expect infants to gain 100 – 150 g/week, and between six and 12 months, 70 – 90 g/week.

Use a growth chart to see if the infant follows a growth centile. Growth charts can be used as a really nice visual guide to show a parent their baby’s feeding is ok. If parents are concerned about feeding because of colic-type symptoms or vomiting and the infant is crossing up centiles, the baby could be overfed. If the infant is dropping centiles, a little more thought is needed as to why.

NICE, in the UK, highlights the following as concerning:

  • a weight below the 2nd centile
  • a fall across one or more centiles in infants with a birth weight below the 9th centile,
  • a fall across two or more centiles in infants with birth weights between 9th and 91st centiles, or
  • a fall across three centiles in infants with a birth weight above the 91st centile.

Poor weight gain could be due to a few different reasons: insufficient calories either because they’re being underfed or difficulties feeding such as swallow difficulties or significant gastro-oesophageal reflux; problems absorbing nutrients or calories such as in cystic fibrosis; or bigger calorie requirements than the infant can manage in feeds such as in congenital heart disease. Initial investigations could include urine samples to rule out occult UTIs, blood to include FBC, U&E, LFT, glucose and TSH, and admission to hospital if inadequate growth is significant or there are concerns about neglect.

The outs:


Physiological gastro-oesophageal reflux is normal. It’s physiological due to low tone in the immature lower oesophageal sphincter, common, occurring in up to 50% of infants under six months, and frequent and can happen up to six times a day. All infants will reflux to some extent. And as long as it’s not causing issues with weight gain, causing infants to be distressed babies, or resulting in feed refusal, it’s usually a case of reassuring the infant’s parents that this is normal. Physiological reflux generally settles when the baby can sit at about six months of age.

Red flags that something more serious may be at play are if the vomiting includes:

  • Onset after six months or persistence after 12 to 18 months
  • Poor weight gain
  • Increasing head circumference, irritability or nocturnal vomiting Bilious – as Tim Horeczko saysGreen vomit is surgical. Green vomit and abdominal distention is surgical. Vomiting and shock is surgical.
  • Projectile – flying over a parent’s shoulder or hitting the wall – may indicate pyloric stenosis.
  • Associated with symptoms of infection – fever, diarrhoea, lethargy

This great article on gastro-oesophageal reflux disease reviews the latest national and international guidelines for GORD management. This framework for organising your thoughts about vomiting delves deeper into each of these differentials.

Peeing and pooing

We are shown lots of photos of poo-filled nappies and several real-life poo-filled nappies, too. Parents often worry about the colour of their baby’s poo. After the sticky, black meconium present in the first few days of life, baby poo can be yellow, orange, mustardy or sometimes green, and this is all completely normal (green poo just means there’s been fast transit time through the gut and the bile is still green coloured). Pale stool from obstructive jaundice is not normal – this infant needs a jaundice workup. Blood or mucous mixed into an infant’s stool is also not normal – it suggests the infant could have colitis from infection, cow’s milk protein allergy or, occasionally, from overfeeding. Red currant jelly stool with large amounts of blood and mucous is abnormal, suggesting intussusception. But blood-stained stool is not part of our normal baby spectrum, so let’s move on.

How many wet nappies does the baby have a day?

Normal is somewhere between 4 and 6. Reduced wet nappies suggest the baby is dehydrated. Dark urine is another sign of obstructive jaundice, and smelly urine could indicate a urinary tract infection.

The parents: feeding is stressful

With any infant presentation to the ED, we should always explore parental well-being. A well baby may be brought in because the parent needs reassurance. But a well baby may also be brought in because the parent needs support. Discussion about mental distress and associated risks such as family violence, self-harm, substance abuse and risk to the infant is challenging but important. The Edinburgh Postnatal Depression Scale is a validated scale for screening for postnatal depression. In the emergency department, we are well-placed to recognise postnatal depression. Several articles described increased rates of postnatal depression since the onset of the COVID-19 pandemic. This post explores postnatal depression and signposts to further reading you may find helpful.

The bottom line

Having a new baby can be stressful, and this has been made worse in our COVID world with reduced access to community support, infant groups and family.

Using a structure that includes assessment of ins (feeding associated weight gain), outs (vomiting, peeing and pooing) and parental wellbeing will identify most clinical concerns.

In infants with good weight gain and no red flags, most parents can be reassured that they’re doing a brilliant job and their baby is thriving.


  • Dani Hall is a PEM consultant in Dublin, member of the DFTB executive team and senior clinical lecturer on the Queen Mary University of London and DFTB PEM MSc. Dani is passionate about advocating for children and young people, and loves good coffee, a good story and her family. She/her.



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