Sucking is a natural and soothing reflex for babies. But is it better for them to suck a pacifier or their thumb?
By about the 16th week of pregnancy, a fetus can bring their hand to their face and suck their fingers. This action is enjoyable and soothing for them. At birth, newborns are immature and vulnerable. They need to form strong bonds with loving and responsive adults in order to survive. If something is bothering them or they feel threatened, a baby may cry to get their parents’ attention, but they may also suck their fingers as they did in the womb.
In addition to allowing babies to feed, the sucking reflex is soothing and relaxing. Sucking triggers the release of endorphins, a type of hormone that creates a feeling of well-being. These hormones help babies calm down, relax, fall asleep, and regulate their sleep/wake cycle.
Pacifiers vs. thumb sucking: Pros and cons
Due to their immaturity, it doesn’t take much for a newborn to feel upset or bothered. That’s why it’s normal, especially during the first few months, for infants to constantly be in need of their parents’ comforting presence. Depending on their temperament, babies may also have a strong need to suck in order to feel calm and safe. Some will suck on a pacifier or their thumb, while others will do neither. Every child is unique.
Today, many pediatricians and dentists recommend pacifier use over thumb sucking. For babies who are breastfed, however, it’s best to wait until breastfeeding is established (i.e., at least 6 weeks) before giving them a pacifier or bottle.
Multiple studies have shown that pacifier use may reduce the risk of sudden infant death syndrome (SIDS).
Pacifiers can be taken away, so it’s easier to make sure they’re only used for short, limited periods. This also makes it easier to eventually wean babies off them.
Since pacifier use can be stopped earlier than thumb sucking, it may have less of an impact on babies’ teeth alignment.
Pacifiers can interfere with the start of breastfeeding if used before the age of 6 weeks.
Pacifiers often fall out, and babies tend to cry when this happens, especially at night.
According to some studies, pacifier use may increase the frequency of middle ear infections.
Children who talk with a pacifier in their mouth can be difficult to understand. This habit can also keep them from learning to express themselves properly.
Children who still suck their thumb or use a pacifier around age 3 may not be able to position their tongue properly in their mouth when swallowing or talking. This can lead to a lisp (mispronouncing certain sounds) or problems swallowing (drooling).
Over time, depending on how often they’re used, pacifiers can lead to teeth misalignment.
What if your child doesn’t like pacifiers?
If your baby isn’t interested in using a pacifier, don’t force them. If it falls out while your baby is sleeping and your baby doesn’t wake up, don’t put it back in their mouth. Don’t put anything on the pacifier (like sugar) to try to make it more appealing.
Thumb sucking pros
Thumb sucking gives babies a way to self-soothe.
Whereas pacifiers can fall out and get lost, a child always has access to their thumb.
Thumb sucking doesn’t interfere too much with a child’s need to talk, express themself, or play. For example, if they want to say something, they can simply take their thumb out of their mouth, which isn’t the case with a pacifier.
Thumb sucking cons
When the time comes, it’s harder to stop a child from sucking their thumb than it is to take away their pacifier.
Children who still suck their thumb around age 3 may not be able to position their tongue properly in their mouth when swallowing or talking. This can lead to a lisp (mispronouncing certain sounds) or problems swallowing (drooling).
Thumb or finger sucking can cause teeth misalignment, especially if the habit continues beyond age 3. In addition, the pressure exerted by the thumb on the palate and jaw appears to be stronger and more damaging than that of a pacifier.
What about the palate?
Contrary to popular belief, pacifiers and thumb sucking do not deform the palate, but rather the dental arch and the alveolar bone that supports the teeth. For some children, these habits don’t result in any dental effects.
Pacifiers and breastfeeding
Studies have shown that pacifier use in the early weeks of life is associated with shorter breastfeeding duration. According to some experts, introducing a pacifier or the bottle to a breastfed baby can lead to “nipple confusion” and perhaps even a preference for bottle-feeding. The baby may start having trouble getting milk from the breast, which could lead to nipple pain or injury, as well as decreased milk production. However, other researchers believe that pacifier use is not the direct cause of early weaning, but rather a sign of difficulties with breastfeeding.
The World Health Organization, the Canadian Paediatric Society, and other health associations suggest that pacifiers should not be offered to a baby until breastfeeding is well established, which can take at least 6 weeks.
If you think your baby needs a pacifier sooner, talk to your doctor or a breastfeeding specialist to make sure that the need for a pacifier isn’t a symptom of another problem.
Once breastfeeding is going well, use pacifiers wisely, meaning only for short, limited periods, and never as a substitute for breastfeeding or quality time with Mom or Dad.
Sucking reflex or hunger?
Babies express hunger in many ways, even while they’re asleep: your little one’s breathing may change, their eyelids may start to flutter, and they might move their arms and legs, stretch, bring their hands to their mouth or face, or make sucking motions. There’s no need to wait until your baby is crying or upset to offer them the breast or bottle.
Toward the end of an effective feeding, babies will often slow their sucking rate, feeding with bursts of sucking followed by long pauses. They’ll become more relaxed and start to nod off. As noted by French pediatrician Marie Thirion, breastfeeding can take the form of nutritive sucking as well as what’s known as comfort nursing. Comfort nursing satisfies your baby’s need to be close to you not only for food, but also to feel loved, soothed, and safe. If you’re okay holding your baby to your breast and don’t feel any pain, you can use these moments to rest and relax too.
Some parents worry that comfort nursing might spoil their baby or create a bad habit. It’s important to know that before the age of 18 to 24 months, an infant’s brain isn’t developed enough for them to be manipulative. In other words, there’s no reason to be concerned about spoiling your baby by fulfilling their need to be close to you.
Pacifier use in premature or sick babies
or sick babies, it’s strongly recommended to introduce the pacifier as soon as possible, as there are many associated benefits for these children. Pacifier use has been shown to calm and soothe them, regulate their breathing, improve their digestion, and facilitate the transition to oral feeding. It also helps alleviate pain when used with breast milk, for example.
How to prevent pacifier dependence
When your baby indicates that they want their pacifier, do a quick assessment first. Why do they need to self-soothe? What’s going on? Which adult is taking care of them? What’s the context? Answering these questions may give you some idea of how to comfort your child without resorting to their pacifier.
- Try to understand your child’s cries. Always check to see if your baby is hungry, tired, or bored before giving them their pacifier. It should never replace food, comfort, or their parents’ touch.
- Comfort your child with affectionate gestures, such as cuddles and soothing words. You can also carry them on your body using a baby carrier. Babywearing is soothing and comforting for babies, and it also helps them sleep.
- Avoid giving your baby a pacifier as a precaution (“just in case”) while they’re calm or playing.
- Try to limit pacifier use at bedtime.
- Observe your child at bedtime and, whenever possible, replace their pacifier with their blankie or another symbolic object they can learn to associate with feeling calm.
- If the pacifier is already in your child’s mouth, get them used to having it taken away by gently removing it when your little one babbles, laughs, plays, crawls, or tries to walk, or while they’re asleep. In addition, try more and more not to give your child their pacifier when they cry. Instead, hold them close, put words to what they’re experiencing, and help them find other ways to calm down.
Why do babies want their pacifier at bedtime?
For infants, bedtime represents a separation. Like all of us, they need to feel safe in order to fall asleep and sleep soundly. That’s why it’s often very important at this time for them to feel their caregiver’s presence, suck on their pacifier or thumb, cuddle their blankie, and follow a routine
or rituals. By listening to your child’s needs and being available to respond to and comfort them, you’re letting them know they can count on you. With time, as their brain develops, they’ll learn to fall asleep on their own.
How long does the sucking habit last?
In general, children grow out of the habit of sucking between the ages of 1 and 3. The Canadian Paediatric Society recommends starting to wean your child off their pacifier at 12 months. Studies show that the need to suck tends to decrease naturally at around 18 months. However, many pediatricians and developmental specialists believe that thumb or pacifier sucking may be necessary up to the age of 2 or 3, as it helps soothe children during certain key learning processes, such as language learning, potty training, and socialization.
When you take care of your baby and meet their needs, including their need to feel secure, they develop a strong and reassuring bond with you. Over time, they learn that they can trust you and feel safe with you. What’s more, your child’s cognitive and language skills progress considerably during their first years of life. With your help, they’re gradually able to put their experiences into words and to reflect, analyze, and make connections. They gain a little more autonomy each day and, at their own pace, learn alternative ways to self-soothe besides thumb or pacifier sucking.
Beyond the age of 4 or 5, the habit of sucking can sometimes delay a child’s development. It’s also important for this habit to stop before their adult teeth have emerged. While some children have little trouble moving on from thumb or pacifier sucking, others need help letting go.
For more information on this topic, read our fact sheet on helping your child stop using a pacifier or sucking their thumb.
Choosing a pacifier
As with all baby accessories, the range of pacifiers on the market is constantly growing. With so many different shapes, sizes, and materials to choose from, it can be hard to make a decision. Here are a few tips to help you narrow things down:
- Silicone or latex? Both materials are equally safe. However, natural rubber (latex) gets soft and sticky more quickly with sterilization, while silicone is firmer and more durable.
“Orthodontic” pacifiers: Just another gimmick!
Doctors and dentists alike say that all pacifiers, including so-called orthodontic pacifiers, can have a negative impact on a child’s teeth.
- Read the label carefully. If you choose a rubber pacifier, check the concentration of N-nitrosamines, a type of carcinogen found in rubber. In Canada, as of 2002, this concentration must not exceed 10 ppb (parts per billion). This standard also applies to rubber nipples on baby bottles.
- Choose a pacifier with a nipple and shield that are suitable for your child. Pacifiers come in smaller sizes for newborns and larger sizes for older infants.
- Some pacifiers have a shield with ventilation holes, which minimize the accumulation of saliva around the mouth. These models are useful when babies are teething.
- Follow your baby’s preferences. If they’ve gotten used to one pacifier in particular, there’s no need to try a new one. You can even buy several of the same model so that you don’t run out.
How to clean a pacifier
- Before giving your child a new pacifier, sterilize it for at least 5 minutes in a pot of boiling water.
- Wash the pacifier daily with warm soapy water and rinse it before giving it to your baby.
- Don’t attempt to clean your baby’s pacifier by putting it in your mouth before giving it to them, as you may be spreading cavity-causing bacteria. If their pacifier falls on the floor, the best thing to do is wash it.
Safe pacifier use
- Check the condition of the pacifier nipple before each use (by pulling on it) to avoid any risk of choking. This preventive measure is important, especially if your child’s teeth have come in.
- Never tie the pacifier around your baby’s neck, around their wrist, or to their crib, and don’t use safety pins, as your little one could hurt themself. Instead, attach the pacifier to their clothing using a secure pacifier clip with a cord no more than 6 to 10 centimetres long.
- Replace the pacifier as soon as it starts to feel sticky, if it’s changed colour or shape, if it has cracks or tears, or if you notice any other signs of wear.
- Ideally, you should replace your baby’s pacifier every two months, regardless of its condition.
- Avoid giving your child a pacifier right after giving them medicine (e.g., antibiotics, vitamins), as some can damage the pacifier.
- Never coat pacifiers with sugar or dip them in a sweet liquid. This can cause tooth decay. In addition, honey can cause botulism in children under a year old.
Things to keep in mind
The sucking reflex develops in the womb. After birth, this reflex allows babies to feed and self-soothe.
The need to suck varies from one infant to another because it depends on a baby’s temperament. You baby may prefer sucking a pacifier, sucking their thumb, or neither.
If your baby likes using a pacifier, make sure to clean it properly and use it safely.
Scientific review: Louise Godin, graduate nurse and IBCLC lactation consultant
Research and copywriting: The Naître et grandir team
Updated: September 2021
Photos: GettyImages/Saturated, Daria Nipot, DGLimages, and PeopleImages
Sources and references
Note: The links to other websites are not updated regularly, and some URLs may have changed since publication. If a link is no longer valid, please use search engines to find the relevant information.
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