How do I know my baby is getting enough breastmilk?

Like adults, babies have different shapes, sizes and metabolisms. One baby might need more or less milk than another. In adults, our appetite and level of thirst changes depending on what we have done that day, how much movement or stimulation we have gotten, whether it's hot or cold outside, or even simply how we are feeling. It is the same for infants. In fact, because babies are growing so quickly, their needs can vary even more from day to day than adults. They are going through growth spurts and phases that mean, at times, they may suddenly want to feed around the clock (often called "cluster feeding").

Babies also differ in terms of how efficient they are at feeding. When breastfeeding, some babies might get all the milk that they need in five minutes. Others might take 30. Some might feed four or five times a day; others, 11 or 12. Even more confusingly, the same baby might want different amounts from hour to hour, day to day, or week to week.

This means that finding objective ways to "measure" whether your baby is getting enough milk can be challenging.

"You can't go on how frequently your baby feeds. You can't go on how long a feed is. You can't go on, 'Are they crying? Are they unsettled?', because that could be for 20 different things," says Emma Pickett, an international board-certified lactation consultant (IBCLC) based in the UK.

Even other signs that many people take to mean a baby is still hungry – such as accepting a bottle after a breastfeed – do not necessarily indicate this, lactation specialists say.

So how can you tell when your baby has gotten enough milk at the breast? What are the signs that they might want to switch breasts, or stop feeding altogether?

And the biggest question of all: How do you know whether, in general, your baby is getting enough milk to grow and thrive? Here are nine tips to know whether your baby is getting enough milk.

1. Feed responsively, not by the clock.

Lactation researchers and specialists agree: feeding responsively, which means offering the breast or bottle according to a baby's hunger cues, rather than by the clock or estimated amount of milk, is important. With breastfeeding, responsive feeding is crucial for ensuring a baby gets enough nutrition and hydration, and to protecting the breastfeeding relationship (and milk supply) for as long as desired. It also supports the bonding between mother and infant.

But knowing how to feed responsively (and what a baby's cues are) isn't always easy. It requires paying close attention to your baby, both before and during a feed.

"If a baby doesn't want to be at the breast anymore, then they're telling us something," says Pickett. That doesn't always mean they want to finish feeding altogether; it might mean they just want to change sides.

2. Know your baby's cues telling you when they are hungry, and when they are full.

What cues might you look for to know if a baby is done feeding? Some babies might start pushing off the breast, or turning their head to the side when it's offered. They might bob on and off the breast, or get fretful, fidgety or squirmy. Or they might be at the breast, but not actively feed from it.

In newborns, some of these behaviors might have more to do with experiencing something like gas rather than being finished with feeding. You might take the baby off the breast and give them a bit of a burp and a cuddle. "But if they're still not happy to be there, they're telling us something – and there's no harm in offering the second side," Pickett says.

If the second side is offered and their behavior continues to signal that they aren't interested, however, they are probably done for the moment.

3. A baby crying does not necessarily mean they are not getting enough milk.

Of course, being fussy or upset is often a sign that a baby is hungry – and putting a baby to the breast is a good way to know, experts say.

But crying doesn't always mean a baby is hungry. Most importantly, crying after a breastfeed does not necessarily indicate that a baby did not have enough milk.

"Babies communicate emotions in different ways," says Rafael Pérez-Escamilla, a leading researcher on infant lactation and professor of public health at Yale University. "They cry for many reasons – it's not always because they are hungry. There may be a lot of light in the room. They want to rest. There are lots of people pinching their cheeks."

For that reason, he and other experts caution, a baby crying, alone, is not a sign that a baby hasn't had enough milk at the breast – although, again, there is no problem with offering them the breast again to be sure.

4. Remember that babies can still feed while they're sleeping.

One popular misconception is that a feed that happens while a baby is sleeping does not provide a baby with nutrition. This can make mothers worry that if a baby often or always falls asleep at the breast, they are not getting enough milk. But this is untrue, and falling asleep at the breast is not, on its own, a reason for worry.

In fact, it is very common for babies to fall asleep at the breast. Young infants, in particular, have a hard time staying awake while breastfeeding. Left to their own devices, they'll usually fall asleep on the first side, Pickett says. When they've woken up, they might want to feed again. At that point, it makes sense to put them on the second side.

But you don't have to worry that a baby who has fallen asleep is not feeding. In fact, a baby is still taking in milk – sometimes a surprising amount – even while they are asleep.

"Feeding reflexes are involuntary reflexes. Sucking and swallowing are involuntary. You do not have to be awake to do them," Pickett says. "While they're in that first phase of sleep, they'll still be actively feeding. They'll still be swallowing. But they'll be happy to be there, and they'll still be getting what they need."

As the baby enters a deeper sleep state, their muscles relax more deeply. This is when you will see them stop feeding, unlatch from the nipple and fall off the breast. Unless it has been medically advised, you do not have to wake your baby up to encourage them to feed more. And you can always offer them the breast again when they wake.

The problem with worrying about feeding while sleeping, Pickett says, is not just that it's unnecessary. It's also that removing a baby who is snoozing and suckling at the breast can affect the milk supply and potentially even a baby's growth long-term.

"The people who are very worried about babies falling asleep at the breast are unlikely to have positive breastfeeding outcomes in the longer term, because they'll be removing babies that really could have had another 20 or 30 per cent of milk if they'd been allowed to stay on," she says.

5. A baby taking a bottle after a breastfeed does not mean they did not get enough milk.

One reason many families believe their infant has not gotten enough milk at the breast is that they offer a bottle after a breastfeed, and the baby gulps it down.

In fact, for the same reason that babies can feed while they're asleep, they can bottle-feed when they are already full. "Until about three or four months, a baby will have a sucking reflex where, literally anything that you put in their mouth, they'll suck," says Olivia Hinge, a UK-based IBCLC and midwife.

Meanwhile, milk comes out of a bottle much more quickly than at the breast, even with a slow-flow teat. As a result, a baby may not signal they are full, such as by trying to push the bottle away or crying, as quickly.

There is not the same concern about overfeeding with breastfeeding, because breastfeeding requires the baby's more active participation. The baby's stimulation at the breast triggers what is called the "milk ejection reflex". This reflex – where milk "shoots" out of the breast –only happens when a baby stimulates the breast with a big movement with their tongue, and it only happens periodically throughout a feed. If a baby is full, they won't stimulate the breast for the same quantity of milk.

6. Know what are (and are not) the signs of having a low supply.

Many breastfeeding mothers have been told that certain symptoms are a sign of having a low milk supply that are not, lactation specialists say.

Breasts going soft, for example, is not a sign of having a lower supply. Nor is breasts no longer leaking, or getting your period back.

One big misconception regards pumping, says Hinge. She often consults with parents who can only pump a little bit of milk, and then worry that this means their baby is only getting a little milk while breastfeeding, too. But the processes are entirely different. "The mechanism of a pump is very crude compared to a baby's mouth," Hinge says. "The release of breastmilk is reliant on oxytocin. So holding your beautiful, warm, cozy baby with a very soft, silky, rhythmic mouth movement, and then the amazing sucking rhythm and peristalsis of the tongue, is so clever and so different to a pump. So it may just be that your body's saying, 'I'm not in love with the pump, I'm in love with the baby.'"

7. If you are wondering if a baby is actively breastfeeding, listen for swallowing.

Watching your baby's hunger and satiety cues, and knowing is important. But another clue can be the sound a baby makes while feeding.

"Audible swallowing is a marker of successful breastfeeding," Pickett says. "Ideally, in a quiet room – especially if they haven't fed them for a while – we should be hearing audible swallowing."

It's also helpful to recognize what a swallow looks like. Usually, it includes the chin coming down, a pause for a moment, and then the chin rising again. Here is a video of the kind of swallowing to watch for.

8. If you are concerned about whether a baby is getting enough milk overall, here are the signs to look out for.

Timing or tracking feeds is not a reliable way of determining whether a baby is getting enough milk. Neither is a baby taking a bottle, falling asleep at the breast, or even crying. And many of the signs we associate with low supply aren't, either.

So how do we know if a baby is getting enough milk or not?

"You're going to look at the whole picture," Pickett says – in particular, at a baby's overall nappy output and weight gain.

In fact, the only real way to know if a baby is getting enough milk is to chart their growth, and their diapers. Signs of not having enough milk include infant weight loss of more than 7 per cent, and fewer than six wet diapers per day and fewer than three bowel movements per day (after the first four days of life).

"Always, always, the baby should be monitored in terms of their growth and development by qualified healthcare providers," Pérez-Escamilla says.

If you are worried, it is important to talk to your baby's health practitioner.

9. Above all, tune in to your own baby – not Google.

The truth, lactation specialists say, is that – aside from rules of thumb like nappy output and weight gain – there is no one list of signs that all babies use to signal when they are getting enough milk, or when they are still hungry. This is why observing your own baby can be so helpful.

"Lots of questions around breastfeeding don't have hard and fast answers," says Pickett. "You are going to be picking up on lots of signals that are subconscious, that you don't even know you're picking up on."

Here at UNICEF, we know that breastfeeding can be challenging. And we believe that, with support, breastfeeding can be possible. This is why we advocate for governments, societies and systems to provide more support so that women who want to breastfeed to be able to breastfeed – for example, by increasing investment in programs that support breastfeeding, implementing policies such as paid maternity leave and breastfeeding breaks, and offering breastfeeding counselling as part of routine health coverage.