Several studies have supported the speculation that pacifiers may protect against sudden infant death syndrome (SIDS). Mitchell and colleagues performed a literature review to determine the effects of pacifier use in infants and whether it reduces the risk of SIDS.

Of eight studies (seven case-control and one prospective), all but one found an association between routine pacifier use and reduced risk of SIDS, a result that was significant when the results were pooled (odds ratio [OR] = 0.83; 95% confidence interval [CI], 0.75 to 0.93). Another series of case-control studies found reduced risk of SIDS associated with pacifier use at last sleep (pooled OR = 0.48; 95% CI, 0.43 to 0.54). Overall, the risk of SIDS appears to be halved in children using pacifiers compared with those not using pacifiers.

The authors propose several possible mechanisms for this association, including airway protection, reduction of gastroesophageal reflux, lighter sleep, and avoidance of the prone sleeping position. Pacifier use may deter children from thumbsucking, but it could decrease breastfeeding. An increased risk of otitis media and oral thrush also has been found, although it is unclear if pacifier use is a cause or an effect of these infections.

The authors conclude that there is evidence favoring pacifier use as a means of preventing SIDS, but that it must be balanced against the risks. Although the means for reduction is uncertain, pacifier use should no longer be actively discouraged.