Context
The World Health Organization and the United Nations Children's Fund
strongly discourage use of pacifiers because of their perceived interference
with breastfeeding. Observational studies have reported a strong association
between pacifier use and early weaning, but such studies are unable to determine
whether the association is causal.Objectives
To test whether regular pacifier use is causally related to weaning
by 3 months postpartum and to examine differences in results according to
randomized intervention allocation vs observational use or nonuse of pacifiers.Design
Double-blind, randomized controlled trial conducted from January 1998
to August 1999.Setting
Postpartum unit of a university teaching hospital in Montreal, Quebec.Participants
A total of 281 healthy, breastfeeding women and their healthy, term
singleton infants.Interventions
Participants were randomly allocated to 1 of 2 counseling interventions
provided by a research nurse trained in location counseling. The experimental
intervention (n = 140) differed from the control (n = 141) by recommending
avoidance of pacifier use and suggesting alternative ways to comfort a crying
or fussing infant.Main Outcome Measures
Early weaning, defined as weaning within the first 3 months, compared
between groups; 24-hour infant behavior logs detailing frequency and duration
of crying, fussing, and pacifier use at 4, 6, and 9 weeks.Results
A total of 258 mother-infant pairs (91.8%) completed follow-up. The
experimental intervention increased total avoidance of pacifier use (38.6%
vs 16.0% in the control group), reduced daily use (40.8% vs 55.7%), and decreased
the mean number of pacifier insertions per day (0.8 vs 2.4 at 4 weeks [P<.001]; 0.8 vs 3.0 at 6 weeks [P<.001]; and 1.3 vs 3.0 at 9 weeks [P =
.004]). In the analysis based on randomized intervention allocation, the experimental
intervention had no discernible effect on weaning at 3 months (18.9% vs 18.3%
in the experimental vs control group; relative risk [RR], 1.0; 95% confidence
interval [CI], 0.6-1.7), and no effect was observed on cry/fuss behavior (in
the experimental vs control groups, respectively, total daily duration, 143
vs 151 minutes at 4 weeks [P = .49]; 128 vs 131 minutes
at 6 weeks [P = .81]; and 110 vs 104 minutes at 9
weeks [P = .58]). When randomized allocation was
ignored, however, we observed a strong observational association between exposure
to daily pacifier use and weaning by 3 months (25.0% vs 12.9% of the exposed
vs unexposed groups; RR, 1.9; 95% CI, 1.1-3.3).Conclusions
We found a strong observational association between pacifier use and
early weaning. No such association was observed, however, when our data were
analyzed by randomized allocation, strongly suggesting that pacifier use is
a marker of breastfeeding difficulties or reduced motivation to breastfeed,
rather than a true cause of early weaning.
Figures in this Article
Pacifiers have been around for a very long time. Small clay pacifiers
have been found in Cypriot graves dating back to about 1000 BC, and breast-shaped
pottery nipples have been recovered from Roman graves dating from around AD
100.1- 2 In the early 1900s, however,
pacifiers began to be condemned by the infant welfare movement. Various reformers
referred to the pacifier as a product of "perverted American ingenuity,"3 an "instrument of torture,"4
and a "curse of babyhood."5 More recently,
clinicians and public health practitioners have raised concerns that the pacifier
causes "nipple confusion" and thereby leads to early weaning.6
In fact, avoidance of pacifiers constitutes step 9 of the World Health Organization/United
Nations Children's Fund Baby-Friendly Hospital Initiative.7
What is the evidence of actual benefit or harm associated with pacifier
use? Several observational studies published since the Baby-Friendly Hospital
Initiative was developed, including studies from Brazil,8- 10
Sweden,11- 12 England,13- 14 New Zealand,15
and the United States,16 have reported a significant
association between pacifier use and early weaning. The question is whether
such an association is causal, or whether pacifier use is a marker of breastfeeding
difficulties or a mother's reduced motivation to continue breastfeeding. No
physiological evidence has validated the concept of nipple confusion; an infant
can apparently distinguish nutritive from nonnutritive sucking.17- 20
It is clear that pacifiers reduce crying in the short term21- 25
but no studies have assessed whether the regular use of pacifiers reduces
the overall duration or frequency of crying and fussing. Such studies are
important, because proscription of pacifier use could conceivably increase
infant distress and thereby impair infant-parent relationships.
The major objectives of our study were to assess whether advice to avoid
pacifier use and to use other modes of calming a crying or fussing infant
reduces the risk of early weaning (before age 3 months) and increases the
frequency or duration of crying and fussing. We also wished to assess the
bias that occurs in using an observational vs an experimental design to study
the effect of pacifier use on breastfeeding duration.