lancet-header
Preprints with The Lancet is part of SSRN´s First Look, a place where journals and other research experts identify content of interest prior to publication. These preprint papers are not peer-reviewed. Authors have either opted in at submission to The Lancet family of journals to post their preprints on Preprints with The Lancet, or submitted directly via SSRN. The usual SSRN checks and a Lancet-specific check for appropriateness and transparency have been applied. Preprints available here are not Lancet publications or necessarily under review with a Lancet journal. These papers should not be used for clinical decision making or reporting of research to a lay audience without indicating that this is preliminary research that has not been peer-reviewed. For more information see the Comment published in The Lancet, or visit The Lancet´s FAQ page, and for any feedback please contact preprints@lancet.com

Daily Use of Pacifier in the First Years of Life Is Associated with Lower IQ at Age Six

21 Pages Posted: 5 Mar 2019

See all articles by Elsa Regina Justo Giugliani

Elsa Regina Justo Giugliani

Universidade Federal do Rio Grande do Sul (UFRGS)

Erissandra Gomes

Universidade Federal do Rio Grande do Sul (UFRGS)

Iná da Silva dos Santos

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Alicia Matijasevich

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Fabio Alberto Camargo-Figuera

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Aluisio Barros

Federal University of Pelotas (UFPel) - International Center for Equity in Health (ICEH); Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

More...

Abstract

Background: Literature on pacifier use is controversial, but mostly suggests negative effects especially on breastfeeding, dental occlusion, and speech development. Little is known about its influence on intelligence. This study assessed the influence of pacifier use duration and intensity on intelligence quotient (IQ) scores in six-year old children from a birth cohort.  

Methods: Data from 3,532 children from the 2004 Pelotas (Brazil) Birth Cohort were analyzed. Children were recruited and assessed at birth and followed-up at three months and at one, two, four, and six years. IQ was estimated using the Wechsler Intelligence Scale for Children. Data on pacifier use duration/intensity were obtained via interviews with mothers at all follow-up visits before age six. Crude and adjusted effects of pacifier use were assessed through linear regression.  

Findings: IQ was negatively associated with all pacifier use indicators. Children who used a pacifier all day long at any assessment had an IQ 0·18 SD lower than those who never used it all day. This effect increased with the number of assessments where all-day-long pacifier use was reported. Children who reported all-day-long pacifier use in the four assessments had an IQ 0·34 SD lower than those who never used it all day.  

Interpretation: We found strong evidence that intense pacifier use up to four years of age is associated with lower IQ at six years. A dose-response effect was observed, with greater IQ reduction in children who used a pacifier for longer. The mechanisms underlying this association need to be clarified.  

Funding Statement: Universidade Federal de Pelotas, ABRASCO, Wellcome Trust (2009-2013), WHO, PRONEX, CNPq, the Brazilian Ministry of Health, and the Child Pastorate.

Declaration of Interests: The authors declare no competing interests.

Ethics Approval Statement: Written informed consent was obtained from all mothers or guardians before data collection. The research ethics committee of the Universidade Federal de Pelotas Medical School approved all follow-up waves of the 2004 Pelotas (Brazil) Birth Cohort.

Keywords: Pacifier; intelligence (test); habits; children

Suggested Citation

Giugliani, Elsa Regina Justo and Gomes, Erissandra and dos Santos, Iná da Silva and Matijasevich, Alicia and Camargo-Figuera, Fabio Alberto and Barros, Aluisio, Daily Use of Pacifier in the First Years of Life Is Associated with Lower IQ at Age Six (02/27/2019 11:59:35). Available at SSRN: https://ssrn.com/abstract=3346507 or http://dx.doi.org/10.2139/ssrn.3346507

Elsa Regina Justo Giugliani

Universidade Federal do Rio Grande do Sul (UFRGS)

Av. Carlos Gomes 1111
Porto Alegre, Rio Grande do Sul 90480-004
Brazil

Erissandra Gomes

Universidade Federal do Rio Grande do Sul (UFRGS)

Av. Carlos Gomes 1111
Porto Alegre, Rio Grande do Sul 90480-004
Brazil

Iná da Silva Dos Santos

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Brazil

Alicia Matijasevich

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Brazil

Fabio Alberto Camargo-Figuera

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology

Brazil

Aluisio Barros (Contact Author)

Federal University of Pelotas (UFPel) - International Center for Equity in Health (ICEH) ( email )

Brazil

Federal University of Pelotas (UFPel) - Postgraduate Program in Epidemiology ( email )

Brazil

Click here to go to TheLancet.com

Paper statistics

Abstract Views
411
Downloads
51