Nonnutritive sucking is a natural reflex for a fetus and newborn, usually manifested by sucking the hands and fingers. The pacifier, also referred to as a “dummy,” has been used as a method for fulfilling this innate desire.¹ Historically, pacifiers were viewed as beneficial until the early 1900s, when an anti-pacifier movement spread concerns that their use led to poor hygiene and indulgent behavior.² At present, there are mixed opinions as to whether pacifier use is beneficial, yet roughly 75 to 85 percent of children in Western countries use a pacifier.³ Table 1 summarizes the risks, benefits, and recommendations for pacifier use at various ages.^4–11

Benefits

ANALGESIA

Pacifiers provide a calming effect and have been used for pain and anxiety prevention. A subgroup of the American Academy of Pediatrics (AAP) lists pacifiers as one of the key methods for pain relief in newborns and infants younger than six months undergoing minor procedures in the emergency department.⁴ A small amount of sucrose solution (2 mL) can be given within two minutes of a procedure, alone or in combination with a nipple or pacifier; the combination appears to be more effective.^12,13 Several studies of full-term and preterm newborns showed that pacifiers were superior to various sweet solutions,^14–16 whereas a study of very preterm newborns showed that pacifiers in combination with sweet solutions were no better than sweet solutions alone.¹⁷ A more recent study confirmed that pacifier use reduces crying time in infants undergoing venipuncture in the emergency department, especially in those younger than three months.¹⁸ Pacifiers have been studied or recommended by the AAP for use with the following procedures: catheterization, circumcision, heel sticks, immunizations, insertion of an intravenous line, lumbar puncture, screening for retinopathy of prematurity, and venipuncture.^{4,13,15,18,19}

PRETERM INFANTS

A Cochrane review found that nonnutritive sucking is associated with shorter hospital stays, earlier transition to bottle feeding from enteral feeding, and improved bottle feeding.²⁰ Although the review did not show that pacifiers have a significant impact on weight gain, behavior, energy intake, heart rate, oxygen saturation, intestinal transit time, or age at full oral feeds, none of the studies reported harmful effects from pacifier use. Overall, pacifier use appears to be a reasonable and inexpensive option for preterm infants.

SUDDEN INFANT DEATH SYNDROME

AAP guidelines suggest offering pacifiers to infants at the onset of sleep to reduce the risk of sudden infant death syndrome (SIDS).⁶ The guidelines recommend not introducing pacifiers to breastfeeding infants until one month of age because later onset of pacifier use appears to have fewer negative effects on breastfeeding.²¹ Pacifiers should not be forced on the infant or reinserted during sleep if the infant spits it out. The exact mechanism of benefit for reducing rates of SIDS is not fully understood, but pacifier use may decrease the likelihood of rolling into the prone position, increase arousal, maintain airway patency, decrease gastroesophageal reflux and resultant sleep apnea, or increase respiratory drive with carbon dioxide retention.²² A meta-analysis²² of seven case-control studies demonstrated a strong association between pacifier use and a reduction in the risk of SIDS, estimating a number needed to treat of 2,733.

Complications

BREASTFEEDING

Observational studies^23–25 and a randomized controlled trial (RCT)²¹ showing that pacifier use is associated with early breast weaning have led to concerns. However, an RCT that studied the effect of pacifier use on breast-feeding in 281 mother-infant pairs for three months postpartum had a different conclusion.²⁶ Although an observational association was noted between pacifier use and early weaning, when the data were analyzed further, the intervention (advice to avoid pacifier use) did not significantly reduce weaning at three months. The authors concluded that pacifier use may be a marker of breast-feeding difficulties, but does not appear to be the cause of early weaning. The intervention group used pacifiers less often, but had no significant difference in crying or fussing, suggesting that other soothing methods are as effective as pacifier use. A more recent RCT on preterm infants did not demonstrate a significant effect of pacifier use on early weaning.²⁷

Because there is conflicting evidence about whether early use of a pacifier disrupts breastfeeding or merely indicates other breastfeeding difficulties, guidelines are cautionary.²⁸ The American Academy of Family Physicians (AAFP) recommends educating mothers about the risks of pacifier use in the immediate postpartum period.⁷ The AAP recommends postponing pacifier use until breastfeeding habits are well established; this recommendation does not contradict use in preterm infants for oral training.⁵

DENTAL HEALTH

A systematic review found inconsistent results regarding the effect of pacifier use on early childhood caries, suggesting that there is no proven correlation.²⁹ A meta-analysis concluded that pacifier use after three years of age is associated with a higher incidence of malocclusion.³⁰ In one study, the prevalence of malocclusion was roughly 71 percent in children who used a pacifier or sucked a digit for more than 48 months, compared with 32 percent in those who ceased sucking between 36 and 48 months, and 14 percent in those who ceased sucking before 24 months.³¹ The most significant malocclusions occurred in children who continued sucking habits beyond 48 months, but there were notable changes in children who continued beyond 24 months. A more recent study confirms these negative dental effects with pacifier use after two years of age.³²

Studies comparing orthodontic and conventional pacifiers found minor differences in malocclusion.^33,34 The American Dental Association and the American Academy of Pediatric Dentistry recommend that pacifier use be discouraged after four years of age.^10,11

INFECTION

Several studies have shown that pacifiers are often colonized with Candida and bacterial organisms (typically nonpathogenic).^35–37 One study found 21 of 40 pacifiers to have a positive culture finding, with none containing the common pathogens of otitis media.³⁸ Latex pacifiers are more significantly colonized with Candida and Staphylococcus than silicone pacifiers.^36,39

A population-based study of more than 10,000 infants in the United Kingdom evaluated pacifier use and finger sucking at 15 months of age and their association with infection at 18 months of age.⁴⁰ The 36 percent of infants who used a pacifier had a higher incidence of earache and colic compared with the 40 percent of infants who did not suck and the 21 percent of infants who sucked fingers. The 2.7 percent of infants who sucked both a pacifier and fingers had more wheezing and earaches and poorer health in the month before the study. One explanation for the association between pacifier use and illness may be that pacifiers were used to calm sick infants. A direct link between illness and type of sucking habit could not be determined from this study; more research is needed before recommendations can be made.⁴⁰

A systematic review of epidemiologic studies found three studies that showed an association between pacifier use and infection, such as otitis media, dental infection, and respiratory and gastrointestinal symptoms.⁴¹ These studies are also too limited to draw conclusions. Although some evidence exists for pacifier colonization with microorganisms, the direct association between these organisms and infection has not been proven.

OTITIS MEDIA

There are two proposed mechanisms for how pacifier use could cause otitis media: reflux of nasopharyngeal secretions into the middle ear from sucking, and eustachian tube dysfunction from altered dental structure.⁴² A meta-analysis, including 22 studies from various countries, showed that pacifier use increased the risk of developing otitis media, with a risk ratio (RR) of 1.24.⁴³ Infants in day care outside the home had an RR of 2.45, those in family day care had an RR of 1.59, and those with a parent who smoked had an RR of 1.66. Breastfeeding reduced the risk of otitis media, with an RR of 0.87.

One widely cited, open, controlled cohort study of more than 400 patients evaluated the incidence of otitis media in infants whose parents were counseled to restrict pacifier use to when the infant was falling asleep. This counseling reduced continuous pacifier use by 21 percent and led to 29 percent fewer episodes of otitis media in the intervention group.³ A more recent prospective cohort study from the Netherlands found that 35 percent of 216 children using pacifiers and 32 percent of 260 children in the control group developed at least one episode of otitis media.⁴² However, rates of recurrent otitis media were higher in the pacifier group (16 versus 11 percent), leading the authors to conclude that pacifier use may increase the risk of recurrent otitis media.

AAFP/AAP joint guidelines on otitis media, which are based on evidence from cohort studies, recommend that physicians advocate for little to no use of pacifiers in the second six months of life to prevent otitis media.⁸ The Institute for Clinical Systems Improvement makes a similar recommendation, but suggests avoiding use by 10 months of age.⁹

Approach to the Patient

In addition to reviewing the risks and benefits of pacifiers, physicians should also counsel parents about the safe use of pacifiers.⁴⁴ Parents or caregivers should not put sweet substances on pacifiers to entice the infant. Pacifiers should be cleaned and replaced regularly to maintain good hygiene and avoid mechanical hazards.^6,45 Manufacturing standards from the U.S. Consumer Product Safety Commission are available at http://www.cpsc.gov/businfo/regsumpacifier.pdf, and pacifier recalls are available at http://www.cpsc.gov/cpscpub/prerel/prerel.html.

Pacifier use should no longer be actively discouraged and may be especially beneficial in the first six months of life. However, the risks begin to outweigh the benefits around six to 10 months of age and appear to increase after two years of age. Because research suggests that limiting pacifier use does not significantly affect crying or fussing, physicians should be prepared to counsel parents about soothing alternatives and pacifier weaning. Physicians should be mindful that after six months of age, pacifiers transform from a means of nonnutritive sucking to objects of affection that give the child a sense of security.³ Removing the pacifier can be a great source of anxiety for children and parents. Key alternatives to pacifier use in younger infants include swaddling, rocking, soft music, singing, and infant massage.⁴⁶ Older infants or toddlers may be distracted from pacifiers with activities, toys, or other objects of affection. Some weaning methods that have been studied include physician or parent encouragement, putting unpalatable substances on the pacifier, and stopping the habit abruptly.⁴⁷