Even though they are tiny and brand new to the world, newborn babies have a very clever trick up their sleeves to get mums to spring to attention and meet their needs. All they have to do is cry. It’s a good job it works so well too, as babies are entirely dependent on adults for their survival. Lovely though they are, new mums are not only responding to their baby crying out of the goodness of their hearts. A cry affects a mothers’ brain and body in ways you would not expect.

A baby’s cry triggers the flight or fight response

Researchers have found that a cry activates the amygalda – that’s the part of the brain that controls the flight or fight response. It’s a primitive reaction that floods the body with adrenalin, gets our hearts racing and escalates our blood pressure. A baby’s cry can even make a mother’s hands and feet sweaty and gets her alert and ready for action. In other words, it’s pretty hard to ignore. It seems humans (and mums especially) are hard-wired to respond quickly to a baby’s cry.

A rush of the ‘cuddle hormone’

After giving birth, a mother’s body is flooded with the hormone oxytocin. More is produced when they breastfeed, snuggle or even look at their babies. Known as the ‘love hormone’ or the ‘cuddle hormone’ oxytocin promotes bonding and attachment.

What is interesting is that oxytocin is also released when a mum hears her baby crying and it prompts her to react and give comfort. Over time, the sound-sending neurons in the brain get better at recognising baby’s cries and mums grow more responsive still.

Are we like mice?

A ground breaking experiment carried out on mice in 2015 helped scientists understand more clearly how the ‘cuddle hormone’ turns mothers into mums. Like humans, baby mice cry to get their mother’s attention.

Researchers first placed virgin mice into a pen of baby mice. When the pups started crying, the adult mice barely batted an eyelid. They seemed completely indifferent to the pups’ cries and made no effort to approach them or look after them in any way. Scientists then injected the virgin mice with oxytocin and popped them back into the pen. This time when they heard the sound of crying the mice rushed over to the pups, picked them up by the scruff of their neck and returned them to the safety of the nest to spend time taking care of them. The scientists were amazed that changes in the mice’s behaviour happened so quickly after they were given oxytocin. In some mice the reaction was almost instantaneous. Mice that had been ignoring the crying pups suddenly rushed over to retrieve them and attend to their distress.

In the same experiment it was found that as time went on, the mice became more quickly attuned to the sound of the crying pups and reacted more promptly.

These same hormones that flood a new mum’s body during pregnancy, labour and then after birth prime them to be alert to their baby’s cries and react instantly to find a way to soothe them. Bodies really are amazing things. As are new mums!

Why do my boobs leak when I hear a baby cry?

Whether this is true or not is hotly debated. While there may not be a scientific study to back it up, many mums swear that it happens. No sooner do they hear a baby crying, than two wet patches start appearing on their t-shirts as their milk begins to flow. Not the best look when you’re in the middle of the supermarket. There is some science to suggest it’s not just something mums are making up. It is thought that the sound of a baby crying triggers an emotional response in mums. This leads to an increase in the production of oxytocin in the blood, which is the same hormone that triggers the let down of milk when you are breastfeeding. This hormone could be the cause of leaking boobs when mums hearing a baby cry.

Why it’s harder for mums to ignore their baby’s cry than for dads

Mums can be in a really deep sleep but will jolt awake the moment they hear their baby cry. Dads, on the other hand, seem to be able to carry on sleeping like a log. Are they just faking it so they don’t have to get up? Well, according to research, maybe not.

There was an experiment carried out in 2013 where 18 men and women were placed in a brain scanner. They were then played recordings of a hungry baby crying. The cries affected the sexes in very different ways. In women, the cries interrupted normal brain activity. In men, their brains ‘carried on without interruption’.

Why a baby’s cry is so hard to ignore

Crying is a primitive behaviour shared by all mammals. It is designed to have a specific effect on the listener, activating the parts of an adult’s brain that are important for giving attention and empathy. It’s not just parents but ALL humans who are able to pick out a baby’s cry even in a mix of other sounds. Our brains respond to the sound of crying milliseconds before we even fully process it, making it an involuntary reaction. Christine Parsons, a researcher from the University of Oxford who looked into the way the brain responds to a baby’s cry, says: “When you hear a baby on a plane, you’re alert, even if you don’t want to hear it. It’s a sound that’s very difficult to ignore.”

A 2011 study also revealed that listening to a baby’s cry triggers stress hormones in a mother and prompts them to act quickly to soothe their infant. Mothers therefore try to lower their own stress by stopping their baby crying. 2017 research from the National Institutes of Health revealed that mums respond within five seconds to their crying baby by picking them up and talking to them. It seems that new mums just can’t help responding, no matter how sleepy they are.

Why it’s so hard when your baby cries a lot

All this research explains just how hard it is for a new mum to ignore her baby crying. She has an inbuilt physical drive to rush to soothe the tears. It explains just how amazing the human body is, in the way that it changes during pregnancy and after birth to prime a mum to care for her baby. It also shows just how distressing a baby’s cries can be to new mums, especially if they are difficult to soothe.

What to do if your baby is hard to settle

Some babies cry more than others. Some are easier to soothe than others. Some have colic and will cry for several hours each evening no matter how hard you try to calm them. Excessive baby crying can be really hard on new mums (and dads). If your baby cries a lot make sure that your first step is to visit your doctor to check that there is nothing bigger going on. For example baby may not be getting enough food or he may have discomfort from colic or reflux, or both. A doctor can check your baby is well and otherwise healthy. They may also have solutions to make your baby more comfortable if it is a case of something like colic or reflux.

If your baby is diagnosed as being otherwise healthy but just cries a lot, then it’s important to find ways to take a little time out and lower your stress levels. It’s worth taking your baby out in a pram or strapped in a sling, so that you can escape the four walls and the cacophony of crying. Cries always sound quieter out in the big wide world and pounding the pavements can help you tune out and relax a little. Even better, babies will often settle and stop crying, even if it’s just for a little while, while you walk. You can find more ideas and helpful tips on how to soothe a crying baby in our article Tips to help your newborn baby sleep.

If your baby cries a lot (e.g. with colic) then it’s important to share the load and get support. Ask your partner, mum or best friend to take over baby care duties for a while, so that you can take a break. Even if you just have a shower, go to a yoga class or for a power walk, you will feel refreshed and more able to resume mummy duties when you get back.

Remember that this is a phase and it won’t last forever. Your baby’s crying will eventually soothe.

When it all gets too much

If you are worried about how much your baby is crying or the effect it is having on you then always ask your midwife or general practitioner for advice.
If you are afraid that you may shake or otherwise hurt your baby, put her down in a safe place, such as her cot, and go to another room for a few minutes to calm down, maybe even have a cup of tea. Get help immediately by calling your partner, a friend, neighbour or Cry-sis, a UK charity offering help and support to parents with babies who cry excessively or have sleeping problems.