BIRTH 36:3 September 2009 267 LETTER Pacifiers and Breastfeeding To the Editor: We read with interest the study by Kronborg and Væth (1). Like most previous observational studies the paper describes an association between pacifier use and shortened breastfeeding duration (1,2). The question is relevant in view of the increase in information about an association between pacifier use and a reduced risk of sudden infant death syndrome (SIDS) (3). It is impor- tant to note that the association does not prove that the instrument (pacifier) is the cause of such an effect. Moth- ers who have breastfeeding difficulties or who simply are not committed to breastfeeding may use the pacifier to prevent infant crying. The gold standard to prove causal effect is a ran- domized controlled trial. All published randomized con- trolled trials performed to evaluate if pacifiers or the advice to use them or not modify the success of breast- feeding have been recently summarized in a systematic review (2). The review clearly shows that such a rela- tionship does not exist. Furthermore, we have recently presented the results of a large randomized controlled trial which demonstrates that in mothers committed to breastfeeding and who are successfully breastfeed- ing at 2 weeks, the recommendation to use a pacifier does not modify the prevalence of exclusive or partial breastfeeding (4,5). Both breastfeeding and use of pacifiers decrease the incidence of SIDS. In mothers who are successfully breastfeeding at 2 weeks, to discourage the use of paci- fiers on the basis of a supposed adverse effect on the success and duration of breastfeeding appears neither justified nor in the best interest of the infant. Alejandro Jenik, MD Professor of Pediatrics, School of Medicine, Hospital Italiano de Buenos Aires. Senior Staff, Division of Newborn Medicine, Department of Pediatrics, Hospital Italiano de Buenos Aires, Argentina Nestor E. Vain, MD Chief, Department of Pediatrics and Neonatology, Sanatorio de la Trinidad Palermo, Buenos Aires, Argentina. Professor of Pediatrics, Faculty of Medicine, Universidad de Buenos Aires. Director, Fundaci´ on para la Salud Materno Infantil (Fundasamin), Buenos Aires, Argentina Address correspondence to: Nestor E. Vain, MD; e-mail: vain@fibertel.com.ar References 1. Kronborg H, Væth M. How are effective breastfeeding technique and pacifier use related to breastfeeding problems and breastfeed- ing duration? Birth 2009;6(1):34–42. 2. O’Connor NR, Tanabe KO, Siadaty MS, Hauck FR. Pacifiers and breastfeeding: A systematic review. Arch Pediatr Adolesc Med 2009;163(4):378–382. 3. Venneman MM, Bajanowski T, Brinkmann B, Jorch G, Sauerland C, Mitchell EA; GeSID Study Group. Sleep environment risk fac- tors for sudden infant death syndrome: The German sudden infant death syndrome study. Pediatrics 2009;123(4):1162–1170. 4. Jenik A, Vain N, Gorenstein A, Jacobi N. Does the recommen- dation to use a pacifier influence the prevalence of breastfeeding? Results of a multicenter, randomized, clinical trial. 2008 Pediatric Academic Societies. Annual Meeting. Poster presentation. Hawaii, Honolulu, May 3–6, 2008. 5. Jenik A, Vain N, Gorenstein A, Jacobi N. Does the recommen- dation to use a pacifier influence the prevalence of breastfeeding? J Pediatr. In press.