How do babies drink from the breast?

Breastfeeding is so instinctive. But there's a lot going on behind those chubby baby cheeks. Find out how breastfeeding works, from the inside out.

Understanding the physiology and biomechanics of breastfeeding is fascinating - and useful information, too. It all begins with the right setting. Though breastfeeding in noisy, busy locations is sometimes a necessity, the best atmosphere is one that induces calm.

The perfect setting

Moms need a comfortable place to sit, away from the hubbub of daily life. Listening to some nice music, or a soothing voice on a favorite podcast also helps set the mood. Your baby is also part of this perfect setting - listening to her sounds, touching her soft skin and inhaling that wonderful baby scent.

It sounds like an idyllic world. But there's a physiological reason for all this pampering. These are all ways to help stimulate a mother's milk ejection reflex - otherwise known as the oxytocin or letdown reflex. Oxytocin is the "love hormone", and as this happy hormone flows, so does the milk.

A good latch

While the mother's body is responding to all those signals, baby is also responding to her mom's unique scent and touch - and understands that it's time to breastfeed, too.

To get ready to drink, a baby needs to latch onto her mother's breast. A good latch begins with the baby opening her mouth wide. Then she should instinctively reach out towards mom's breast with her tongue and jaw - and fit the nipple and areola into her mouth.

As baby's mouth closes, her lips form a seal. By suckling, she makes mom's breast stretch out to between her tongue and the roof of her mouth - all the way to the point where the hard palate meets the soft palate.

Triggering milk ejection

Now it's time for baby to start drinking. She achieves this by compressing her mother's breast rhythmically, using a wave-like motion known as peristalsis. This action - coupled with pressure applied to the areola by baby's jaw - triggers nerves in the nipple.

This gets those oxytocin and prolactin hormones going, which triggers the milk ejection reflex. And as baby's tongue continues to undulate like a wave, milk is squeezed from the breast to the back of baby's throat, ready for swallowing. All in all, babies use 25 pairs of muscles while they are nursing.

Active drinking

Your baby is the boss of the breast - as she's the one who controls how fast (or slow) she feeds. Babies are able to extract milk from their mother's breast, and they have the power to make the milk stop flowing. Just by stopping the peristaltic motion and suckling action.

Babies naturally - and very precisely - coordinate between suckling, swallowing and breathing. A sign that baby is actively drinking can be heard as she rhythmically grunts or gulps. But what's going on inside her mouth?

After every swallow of mother's milk, baby takes a quick breath - then suckles again. This rhythm of drink-swallow-breathe repeats until baby stops altogether, to take a break and just breathe. Then it's time to start feeding again, until baby's belly is full and feeding time is over.