Newborns hiccup frequently because their diaphragm, the main breathing muscle, is still immature and easily irritated. These sudden, involuntary contractions are not only harmless but may actually serve an important developmental purpose: helping your baby’s brain learn to control breathing. Most newborns hiccup multiple times a day, and episodes typically resolve on their own within 5 to 10 minutes.
What Happens Inside During a Hiccup
A hiccup is a sudden, involuntary contraction of the diaphragm and the small muscles between the ribs. The contraction pulls air rapidly into the lungs, and the vocal cords snap shut almost immediately afterward, producing the familiar “hic” sound. The whole sequence takes a fraction of a second and repeats in a rhythmic pattern.
This process is controlled by a reflex arc with three parts. Sensory signals travel along the phrenic nerve and the vagus nerve to a processing center in the brainstem. The brainstem then fires motor signals back down the phrenic nerve to the diaphragm, triggering the contraction. In newborns, this reflex arc is particularly sensitive. Their nervous system is still developing, and the threshold for triggering these involuntary contractions is much lower than it will be later in life.
Hiccups May Help Your Baby’s Brain Develop
A 2019 study from University College London found that hiccups aren’t just a quirk of immaturity. They may play an active role in brain development. Researchers placed brain-monitoring electrodes on 13 newborns (ranging from 30 to 42 weeks gestational age) while also tracking diaphragm contractions with sensors on their torsos. Each hiccup produced three distinct brainwaves in the cortex, the part of the brain that processes sensory information.
The researchers believe the third brainwave is especially significant: it may help the baby’s brain connect the “hic” sound it hears with the physical sensation of the diaphragm contracting. In other words, each hiccup gives the brain a small lesson in body awareness. Senior author Dr. Lorenzo Fabrizi explained that hiccups may help the brain “learn how to monitor the breathing muscles so that eventually breathing can be voluntarily controlled.” At birth, the neural circuits that process body sensations are not fully wired, so this kind of repeated sensory feedback is a crucial part of early development.
Hiccups Start Long Before Birth
Your baby was hiccuping well before delivery. Fetal hiccups can begin as early as the first trimester, though most pregnant people start feeling them in the second or third trimester as rhythmic, repetitive twitches in the belly. In the womb, the diaphragm works the same way it will after birth, contracting downward to draw fluid into the lungs. The difference is that the fetus isn’t breathing air. It’s inhaling amniotic fluid.
Hiccups follow the same rhythmic motion as breathing but with more forceful contractions. This repeated exercise of the diaphragm is thought to help the respiratory muscles strengthen and coordinate before they’re needed for actual breathing at birth. So by the time your newborn arrives, hiccuping is already a well-practiced reflex.
Common Triggers in Newborns
Several everyday situations can set off the hiccup reflex in a newborn:
- Stomach distension from feeding. A full stomach presses against the diaphragm from below. This is the most common trigger, which is why hiccups so often appear during or right after a meal.
- Swallowing air. Babies swallow air while nursing or bottle-feeding, especially if the latch isn’t ideal or the bottle nipple flows too fast. That extra air in the stomach adds to the pressure on the diaphragm.
- Eating too quickly. A fast, eager feeder takes in more air and fills the stomach rapidly, both of which irritate the diaphragm.
- Temperature changes. A sudden drop in body temperature, like during a diaper change, can occasionally trigger a hiccup episode.
How to Help When Your Baby Hiccups
Most of the time, you don’t need to do anything. Hiccups rarely bother newborns the way they bother adults. Your baby may hiccup right through a nap without waking. If an episode lasts more than 5 to 10 minutes, the American Academy of Pediatrics’ HealthyChildren.org suggests resuming feeding for a few minutes, which usually stops them.
A few practical strategies can reduce how often hiccups happen in the first place. Burping your baby midway through a feeding (not just at the end) helps release swallowed air before it builds up. Keeping your baby in a more upright position during and for 15 to 20 minutes after feeding lets gravity help the stomach settle. If you’re bottle-feeding, a slow-flow nipple can prevent your baby from gulping too fast.
One important note: never try adult hiccup remedies on a newborn. Startling the baby, pressing on the fontanelle, or pulling on the tongue are all unsafe and ineffective. The same goes for holding a baby’s breath, which you should never attempt.
When Hiccups Signal Something Else
Frequent hiccups alone are normal. But hiccups paired with other symptoms can occasionally point to gastroesophageal reflux, a condition where stomach contents flow back into the esophagus. In most infants, some degree of reflux is normal (that’s what spit-up is). It becomes a concern when it’s accompanied by more serious signs.
Watch for these patterns that warrant a call to your pediatrician:
- Forceful, projectile vomiting or vomit that contains blood or looks like coffee grounds
- Vomit that is green or yellow, which indicates bile
- Unusual irritability or crying that goes well beyond your baby’s normal fussiness
- Poor weight gain or actual weight loss
- Difficulty breathing or swallowing during or after feeds
- Signs of dehydration, such as no wet diapers for three or more hours
Reflux-related vomiting that starts before two weeks of age or after six months is also considered unusual and worth discussing with a doctor. On its own, though, a baby who hiccups several times a day, feeds well, gains weight normally, and seems comfortable is doing exactly what newborns are supposed to do. The hiccups will become less frequent as the diaphragm matures and the nervous system finishes building those early sensory connections, typically within the first few months of life.