Thumb Sucking Versus Pacifier Use

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Sucking is one of the most primitive reflexes that humans have. Many babies and toddlers use sucking not only as a means for getting food, but also for comfort. Non-nutritive sucking, such as sucking on the breast at the end of a feeding or on a finger, thumb, or pacifier, is normal behavior for infants and young children.

In addition to being a source of comfort for many babies, pacifiers also lower the risk of sudden infant death syndrome (SIDS) when offered at naps and bedtime.

Pacifiers Protect Against SIDS

In a review of evidence published in 2016 in the journal Pediatrics, authors cited multiple studies on the protective effect of pacifiers. These studies found that pacifiers could decrease SIDS by as much as 90%.

While it isn't clear exactly how pacifiers provide protection, one possibility is that they help airways remain open. Another is that they help a baby's autonomic nervous system (which regulates breathing and heart rate) function properly. These protective effects are still present even if the pacifier falls out of the baby's mouth after they fall asleep.

The AAP recommends parents consider offering babies a pacifier at bedtime to reduce the risk of SIDS. If your baby is breastfeeding, you may wish to wait until breastfeeding is going well (when the baby is three to four weeks old), but there is little evidence that pacifiers affect breastfeeding.

Other Pacifier Pros (and Cons)

One argument for preferring pacifiers over thumbs and fingers is you can simply take away a pacifier if a child develops a prolonged pacifier habit. On the other hand, your child's fingers and thumb are right there if they want to suck on them.

Some experts also argue that so-called "orthodontic" pacifiers are less likely to cause dental problems. However, the American Academy of Pediatric Dentistry states that thumb, finger, and pacifier sucking all affect the teeth essentially the same way and that most children stop before the permanent teeth come in and any harm is done to their teeth or jaws.

On the downside, at least one older study has suggested that using a pacifier (or bottle) can increase the risk of ear infections, possibly because the sucking motion may block proper airflow through the eustachian tubes, which normally keep the middle ear open and clean.

More recent research is limited to small studies and provides conflicting evidence on this question. One study of 340 babies found pacifier use to be one risk factor, of several, for ear infection. But another tracked 780 babies and found no difference in frequency of ear infections among pacifier users and non-pacifier users.

Using a pacifier is no guarantee that your child won't become a thumb sucker. One study found that 20% of daily pacifier users also sucked a thumb or finger every day.

Thumb-Sucking Pros and Cons

The main reason to prefer finger and thumb-sucking over a pacifier is that your infant doesn't need you to continuously put their thumb in their mouth whenever they need it. (This can have you getting up several times during the night if your baby cries each time the pacifier falls out.)

Once your baby learns to find them, their fingers or thumb will always be available, so they can reliably use them for self-soothing. Still, thumb-sucking habits can be harder to break, and thumb suckers are more likely to develop prolonged sucking habits.

Most importantly, there haven't been any studies to show that sucking on fingers and thumbs offers the same benefit in reducing the risk of SIDS, which would be a big reason to prefer pacifier use.

  • Studies show that use during sleep reduces the risk of SIDS

  • May have adverse dental effects if continued past age 2 years

Thumb Sucking
  • No evidence it may reduce risk of SIDS

  • Always available

  • May be a harder habit to break than pacifier use

  • May expose child to more germs

  • May have adverse dental effects if continued past age 2

Pacifier Tips

Things to keep in mind about pacifiers:

  • Keep extras: Choose silicone, one-piece, dishwasher-safe pacifiers and keep a few backups on hand in case you lose one.
  • Maintain: Replace pacifiers often and use the appropriate size for your baby's age. Watch for loose parts or signs of deterioration. Never attach a pacifier to a string or strap long enough to get caught around your baby's neck.
  • Sanitize: Keep pacifiers clean (especially before your baby is six months old and their immune system has matured). You can wash them with soap and water or in the dishwasher. Resist the temptation to put the pacifier in your own mouth to clean it; you'll only spread more germs to your baby. (Keep fingers clean as well if your child prefers them.)
  • Follow baby's lead: If your baby's not interested in the pacifier, don't force it.

A Word From Verywell

The fact that both thumb sucking and pacifier use can turn into prolonged habits, sometimes into first grade or beyond, may lead you to think that you should avoid both—but remember that sucking either one is normal in a baby's first year and the majority of kids give it up easily.

Finally, while it is nice to think you can choose whether your baby will use a pacifier or suck their thumb, in reality, you can't usually make that choice. Many babies simply prefer one or the other—or neither.

9 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Academy of Pediatrics. Safe sleep: Recommendations.

  2. Moon RY, Task Force on Sudden Infant Death Syndrome. SIDS and other sleep-related infant deaths: Evidence base for 2016 updated recommendations for a safe infant sleeping environment. Pediatrics. 2016;138(5):e20162940. doi:10.1542/peds.2016-2940

  3. Jaafar SH, Ho JJ, Jahanfar S, Angolkar M. Effect of restricted pacifier use in breastfeeding term infants for increasing duration of breastfeeding. Cochrane Database Syst Rev. 2016;(8):CD007202. doi:10.1002/14651858.cd007202.pub4

  4. Schmid KM, Kugler R, Nalabothu P, Bosch C, Verna C. The effect of pacifier sucking on orofacial structures: a systematic literature review. Prog Orthod. 2018;19(1):8. doi:10.1186/s40510-018-0206-4

  5. American Academy of Pediatric Dentistry. Cold turkey: How to convince baby it's time to part with the pacifier.

  6. Hanafin S, Griffiths P. Does pacifier use cause ear infections in young children?. Br J Community Nurs. 2002;7(4):206, 208-11. doi:10.12968/bjcn.2002.7.4.10227

  7. Salah M, Abdel-Aziz M, Al-Farok A, Jebrini A. Recurrent acute otitis media in infants: Analysis of risk factors. Int J Pediatr Otorhinolaryngol. 2013;77(10):1665-1669. doi:10.1016/j.ijporl.2013.07.022

  8. Walsh P, Vieth T, Rodriguez C, et al. Using a pacifier to decrease sudden infant death syndrome: an emergency department educational intervention. PeerJ. 2014;2:e309. doi:10.7717/peerj.309

  9. Ling HTB, Sum FHKMH, Zhang L, et al. The association between nutritive, non-nutritive sucking habits and primary dental occlusion. BMC Oral Health. 2018;18(1):145. doi:10.1186/s12903-018-0610-7

Additional Reading

By Vincent Iannelli, MD
Vincent Iannelli, MD, is a board-certified pediatrician and fellow of the American Academy of Pediatrics. Dr. Iannelli has cared for children for more than 20 years.