review article is bed sharing beneficial and safe during
TRANSCRIPT
Review ArticleIs ‘‘Bed Sharing’’ Beneficial and Safe during Infancy?A Systematic Review
Rashmi Ranjan Das,1 M. Jeeva Sankar,2 Ramesh Agarwal,2 and Vinod Kumar Paul2
1 Department of Pediatrics, All India Institute of Medical Sciences, Bhubaneswar 751019, India2Newborn Health and Knowledge Centre (NHKC), Department of Pediatrics, All India Institute of Medical Sciences,New Delhi 110029, India
Correspondence should be addressed to Ramesh Agarwal; [email protected]
Received 5 October 2013; Accepted 25 November 2013; Published 30 January 2014
Academic Editor: Namık Yasar Ozbek
Copyright © 2014 Rashmi Ranjan Das et al. This is an open access article distributed under the Creative Commons AttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properlycited.
Background. There is conflicting evidence regarding the safety and efficacy of bed sharing during infancy—while it has been shownto facilitate breastfeeding and provide protection against hypothermia, it has been identified as a risk factor for SIDS. Methods. Asystematic search of major databases was conducted. Eligible studies were observational studies that enrolled infants in the first4 weeks of life and followed them up for a variable period of time thereafter. Results. A total of 21 studies were included. Thoughthe quality of evidence was low, bed sharing was found to be associated with higher breastfeeding rates at 4 weeks of age (75.5%versus 50%, OR 3.09 (95% CI 2.67 to 3.58), 𝑃 = 0.043) and an increased risk of SIDS (23.3% versus 11.2%, OR 2.36 (95% CI 1.97 to2.83), 𝑃 = 0.025). Majority of the studies were from developed countries, and the effect was almost consistent across the studies.Conclusion. There is low quality evidence that bed sharing is associated with higher breast feeding rates at 4 weeks of age and anincreased risk of SIDS. We need more studies that look at bed sharing, breast feeding, and hazardous circumstance that put babiesat risk.
1. Background
In olden days, mothers and babies were separated after birthto prevent infectious diseases and to keep newborns in a safeand controlled environment. The practice of “rooming-in”(keeping the mother and the baby in same room) startedwhen it was realized that the separation had serious impli-cations for the emotional and psychological development ofboth mothers and newborns [1]. Rooming-in is now rec-ommended by the World Health Organization (WHO) andUNICEF as part of the Baby Friendly Hospital Initiative(BFHI) programme to promote breastfeeding [2].
During rooming-in, the infant is placed close to themother either by bed sharing, by an attached side-car crib,or by her bedside in a standalone cot. Of these, the “ideal”methodwould be “bed sharing” in which the newborn is kepton the same bed as that of the mother. The “bed sharing”behavior, however, is controversial in public health parlance.
Some consider it a significant risk factor for sudden infantdeath syndrome (SIDS) and argue for its wholesale elimi-nation [3–5]. Others disagree, finding little or no scientificevidence for an associationwith SIDS, except among smokingmothers [6–8].
When research into SIDS began in the 1980’s, researchershad little idea of why these babies died. In the 1990’s, bedsharing related to infant sleeping environment was identifiedas one of the risk factors. By the end of this decade, a strongerinteraction between bed sharing and smoking was observed.One recent study exposed an interaction between bed sharingand alcohol/drugs [9]. This study also partially explained thedifference in SIDS rates between cultures where cosleepingis the usual practice. Bed sharing is common in certaincultures where the prevalence of SIDS is high, including theAfrican black populations in the United States, Maori, andAboriginal populations. Bed sharing is common in certaincultures where the prevalence of SIDS is low, including Asian
Hindawi Publishing CorporationInternational Journal of PediatricsVolume 2014, Article ID 468538, 16 pageshttp://dx.doi.org/10.1155/2014/468538
2 International Journal of Pediatrics
communities (Japan, Hong Kong, Bangladesh, and thosein UK) and Pacific Islander communities in New Zealand.Actually, it is not the bed sharing that distinguishes thesecultures, but other factors (e.g., smoking and use of alcohol/drugs) which in conjunction with cosleeping may put infantsat risk [9].
With this background, we conducted present systematicreview to evaluate the efficacy and safety of bed sharing com-pared to no bed sharing during infancy, to provide updatedevidence to the World Health Organization (WHO) which isin the process of reviewing its recommendations on postnatalcare of new born infants and their mothers.
2. Methods
2.1. Types of Studies. We intended to include randomizedand quasirandomized trials that compared bed sharing ofmothers and their infants with no bed sharing. If randomizedstudies were not available, we planned to include observa-tional studies after applying the following eligibility criteria:
(1) cohort studies that enrolled infants in the first 4 weeksof life and followed them up for a variable period oftime thereafter were included;
(2) case-control studies in which
(i) infants being exclusively breastfed at 4–6wk/3-4 months/6 months of age or those who died ofSIDS were the “cases”;
(ii) the exposure (i.e., bed sharing) occurred in theneonatal period for at least a few “cases”; ifthis is not explicitly mentioned in the study, weassumed this if the study had reported the expo-sure status, that is, bed sharing, as a “routine”or “usual” practice;
(3) studies that did not include neonates and measuredthe exposure in the “last sleep” were excluded;
(4) cross-sectional studies that measured the associationbetween breastfeeding status at different time pointsand bed sharing starting from the neonatal perioduntil 1 year of age were included.
We excluded the studies on “rooming-in” if they had notreported bed sharing separately. When there were multiplepublications from one study, only the publication with themost relevant information to the systematic review was used.
2.2. Exposure or Intervention. Bed sharing of mother and herneonate was the exposure studied. Terminology regardingbed sharing, room sharing, and cosleeping used both in thescientific literature and the popular literature is inconsistentand potentially problematic. For the purposes of this paper,“bed sharing” term was used if the newborn was kept on thesame bed as that of the mother.
2.3. Outcome Measures and Their Definitions. The primaryoutcomes were the (a) proportion of infants being breastfed(any or exclusive) at 4–6wk, 3-4 months, and 6 months of
age and (b) proportion of infants dying of SIDS in the firstyear of life. The secondary outcomes were the incidence ofhypothermia, all-causemortality during neonatal period, andincidence of neonatal sepsis.
Exclusive breastfeeding was defined as an infant receivingonly breast milk with no additional foods or liquids, not evenwater except multivitamin supplements or medications, andany breastfeeding means that an infant receives any amountof breast milk regardless of supplements. SIDS was definedas the unexplained death without warning of an apparentlyhealthy infant usually during sleep. Hypothermia was definedas skin temperature <36.5∘C. Neonatal mortality referred todeaths due to all causes occurring in the first 28 days ofpostnatal life while neonatal sepsis was defined as the clinicalsyndromeof bacteremiawith systemic signs and symptoms ofinfection in the first 28 days of postnatal life with or withoutculture positivity.
2.4. Search Methodology. The following databases weresearched independently by three review authors (RashmiRanjan Das, Ramesh Agarwal, M. Jeeva Sankar) using thesearch terms (newborn OR infant OR neonat∗) and (room-ing-in OR bedding-in OR bed share OR bed sharing ORcosleeping OR sleeping). The databases searched were andMEDLINE via PubMed (1966–May 2013), Cochrane CentralRegister of Controlled Trials (CENTRAL, The CochraneLibrary, Issue 6, May 2013), and EMBASE (1988–May 2013).Searches were limited to human studies. There were nolanguage restrictions. For further identification of ongoingtrials, the website http://www.clinicaltrials.gov/ was searchedand relevant trials were screened for eligibility of inclusion inthe review. We also checked the cross-references of relevantarticles. We treated side-car crib exposure (used in somestudies) as no bed sharing.
2.5. Data Extraction. Data extraction was done using astandardized data extraction form that was designed andpilot tested a priori. Three authors (Rashmi Ranjan Das, M.Jeeva Sankar, and Ramesh Agarwal) independently extracteddata from included studies, including year, setting (country,type of population, socioeconomic status, baseline neonatalmortality, baseline practice of rooming-in or bedding-in,gestation, and birth weight of infants), exposure/intervention(bed sharing, routine or last night), and results (outcomemeasures, effect, significance). Disagreements in extracteddata were resolved through discussion.
2.6. Assessment of Risk of Bias in Included Studies. Two reviewauthors (M. Jeeva Sankar, RashmiRanjanDas) independentlyassessed the methodological quality of the selected studies.Quality assessment was undertaken using the NewcastleOttawa Scale (NOS) for observational studies. This scaleassesses the quality under three major headings, namely,selection of the studies (representativeness, exposure assess-ment/control selection), comparability (adjustment formain/additional confounders), and outcome/exposure (adequacyof outcomemeasured, exposure measured versus self-report)[10]. Any disagreement was resolved through discussion withthe third author (Ramesh Agarwal).
International Journal of Pediatrics 3
Records identified through databasesearchingPubMed = 3739
Central = 548
EMBASE = 4726
Records after removal ofduplicates: N = 8748
Records excluded scanning the title and/orabstract: N = 8563
Full-text articles assessed: N = 185
Records excluded: N = 164
Intervention/exposure not studied (N = 80)Outcome not reported (N = 20)No control arm (N = 54)Duplicate publication (N = 10)
Studies included in qualitative analysis: N = 21
SIDS and bed share = 14; breastfeeding and bedshare = 8 (one study reported both outcomes)
Studies included in quantitative analysis: N = 15
Figure 1: Flow of studies.
2.7. DataAnalysis. For each outcomemeasure, the total num-ber of participants and the number of participants experi-encing the event and the adjusted odds ratio (aOR) providedby the study authors were extracted. We intended to useonly aOR for pooling the results. If adjusted ratios were notprovided in a given study, we used the unadjusted OR.
Meta-analysis was done by the generic inverse varianceusing the user written command “metan” in Stata 11.2 (Stata-Corp, College Station, TX). We used the natural logarithmconverted values of aOR and their confidence intervals(CI) for computing the pooled estimates. The heterogeneitybetween the studies was quantified by using a measure of thedegree of inconsistency in their results (𝐼2 statistic). Giventhat all the included studies were observational and had aninherent risk of heterogeneity between them, we planned touse fixed-effect model for pooling their results irrespective ofthe degree of heterogeneity. For the outcome of breastfeedingstatus, we planned to have only one summary result—breastfeeding status at 4 to 6 weeks of age.
3. Results
We identified 9013 articles, of which 21 were found to beeligible for inclusion (breastfeeding and bed sharing = 8; SIDSand bed sharing = 13; one study reported both the outcomes)(Figure 1) [9, 11–30]. A total of 15 studies provided data for thequantitative analysis (Tables 1 and 2) [9, 13, 14, 19–30]. Noneof the included studies were randomized trials (RCTs), as we
could not find any RCT that specifically studied the interven-tion (bed sharing). The 13 studies [9, 19–30] that evaluatedSIDS and bed sharing were case-control studies while amongthe 8 studies reporting breastfeeding rate, one was case-control study [12], and the other seven were cross-sectionalstudies [11, 13–18]. All except three studies [12, 14, 15] werepopulation based. Studies reporting SIDS included 13072infants and provided data up to 2 years of age while thosereporting breastfeeding included 25276 infants and provideddata up to 1 year of age. Majority of the included studies wereof good quality as per the New Castle Ottawa Scale (Table 3).
3.1. Breastfeeding. Only one study reported exclusive breast-feeding rateswhile the others reported any breastfeeding rates[15]. Mailed questionnaires were used to collect data in allstudies except one which used face-to-face interview [15]. Allexcept the one studywere fromdeveloped countries [15]. Lossto follow-up rate varied from 2.2% to 50% in the includedstudies.The risk of bias in these studies was moderate to high(Table 1). Almost all the studies showed a consistent beneficialeffect on any/exclusive breastfeeding rates at the three differ-ent time points, that is, at 4 to 6 weeks, 3 to 4 months, andat 6 months of age. The effect sizes of the individual studiesvaried from 1.5 to 6.7 (Table 1). We could pool the results oftwo studies that reported breastfeeding rates at 4–6 weeksof age [13, 14]. Pooled analysis showed 3-fold odds of beingexposed to bed share during the neonatal period in those whowere breastfed compared to those who were not (pooled OR
4 International Journal of Pediatrics
Table1:Observatio
nalstudies
onbedsharea
ndbreastfeeding.
S.no
.Stud
yID
/site
orcoun
try
Design,
setting
Stud
ypo
pulatio
nNum
bero
fsub
jects
Interventio
n/expo
sure
Outcome(effectsize)
Com
ments
1Flicketal.
2001/U
SA[11]
Cross-sectionalstudy
(with
inan
interventio
nalstudy),
popu
latio
nbased
Pregnant
wom
enenrolledat28
wk,
contactedatarou
nd8
weeks
after
delivery
Question
naire
based
survey
of218
consecutiveinfants
Bedshare
Breastfeedingrate=61/13
3(bed
share),
30/85(nobedshare)
OR(95%
CI):1.5
5(0.86,2.84)
Any
breastfeeding(not
exclu
siveb
reastfeeding
)at8
weeks
ofage.Lo
ssto
follo
wup
was
2.2%
.
2Ba
ll2003/U
nited
Kingdo
m[12]
Case-con
trolstudy,
popu
latio
nbased
Health
infantsa
ndmothers,delivered
at36+weeks.Followed
uptill4
mon
thso
fage
Cases,112
Con
trols,
141
Bedshare
Breastfeedingrate=81/11
2(case),
54/14
1(control)
OR(95%
CI):4.2(2.38,7.4
7)
Any
breastfeeding(not
exclu
siveb
reastfeeding
)for
≥1m
oisthed
efinitio
nof
the
case.L
osstofollo
wup
was
40%.
3Blaira
ndBa
ll2004/U
nited
Kingdo
m[13]
Datafrom
two
studies:one
was
cross-sectionaland
theo
ther
was
long
itudinal,
popu
latio
nbased
Health
yinfantsa
ndtheirm
othersatho
me
Dataa
vailableo
n424
subjects
Bedshare
Breastfeedingrateat4weeks
=73/84(bed
share),113/227
(nobedshare)
OR(95%
CI):6.66
(3.37
,13.3)
Repo
rted
anybreastfeeding
(not
exclu
siveb
reastfeeding
rate).Lo
ssto
follo
wup
was
<20%
Breastfeedingrateat3
mon
ths=
58/74(bed
share),
202/350(nobedshare)
OR(95%
CI):2.66
(1.43,5.14)
4McC
oyetal.
2004/U
SA[14
]Cr
oss-sectionalstudy,
commun
itybased
(follo
wup
atho
meo
finstitu
tionalbirths)
Datafrom
theInfant
Care
Practic
esStud
y(ICP
S)betweenyears
1995
and1998.
Follo
wup
ofinfants
born
atselected
study
hospita
ls
Dataa
vailableo
n10355
subjects
Bedshare
Breastfeedingrateat1m
onth
=1346
/2071(bedshare),
4142/8284(nobedshare)
Adjuste
dOR(95%
CI):3.0
(2.6,3.5)
Repo
rted
anyBF
ratefor>
4weeks.L
osstofollo
wup
was
∼30%
Breastfeedingrateat3m
onths
=725/1346
(bed
share),
3107/900
9(nobedshare)
Adjuste
dOR(95%
CI):3.4
(2.9,
4.0)
Breastfeedingr
atea
t6mon
ths
=518/1243
(bed
share),
2071/9112(nobedshare)
Adjuste
dOR(95%
CI):3.6(3,
4.2)
5Lahr
etal.
2007/U
SA[15]
Cross-sectionalstudy
(rando
msample
survey),po
pulatio
nbased
Stratifi
edsampleo
fwom
endraw
neach
mon
thfro
mrecently
filed
birthcertificates
betweenyears1998
and1999
Dataa
vailableo
n1685
subjects
Bedshare
Breastfeedingrate=485/584
(bed
share),
770/110
1(no
bedshare)
Adjuste
dOR(95%
CI):2.65
(1.72to
4.08)
Any
breastfeeding
for>
4weeks
International Journal of Pediatrics 5
Table1:Con
tinued.
S.no
.Stud
yID
/site
orcoun
try
Design,
setting
Stud
ypo
pulatio
nNum
bero
fsub
jects
Interventio
n/expo
sure
Outcome(effectsize)
Com
ments
6
Blaire
tal.
2010/U
nited
Kingdo
m[16]
Prospective
long
itudinalstudy,
popu
latio
nbased
Infantso
fallpregnant
wom
enresid
ingin
the
3health
distr
ictsof
Avon
;age
grou
p:birth
to4years.Be
dshare
was
categoriz
edinto
thefollowing3
grou
ps:early,
late,and
constant
Dataa
vailableo
n7447
subjects
Bedshare
Breastfeedingrateat6
mon
ths=
733/1415
(con
stant
andearly
bedshare),2111/6
032
(nobedshare)
OR(95%
CI):2.0(1.77to2.25)
Repo
rted
onlybreastfeeding
rate(not
exclu
siveb
reast
feedingrate).Th
eadjustedOR
forb
edsharingin
then
eonatal
ageg
roup
isno
tkno
wn.
Loss
tofollo
wup
was
50%loss.
Breastfeedingrateat12
mon
ths=
322/1415
(con
stant
andearly
bedshare),549/6032
(nobedshare)
OR(95%
CI):2.94
(2.52
to3.44
)
7Tan2011/M
alaysia
[17]
Cross-sectionalstudy,
facilitybased
Mother-infant
pairs
with
infantsu
pto
6mon
thsa
ttend
ing
health
clinics
over
4mon
thsinyear
2006
Dataa
vailableo
n682
subjects
Bedshare
Breastfeedingrate=249/501
(bed
share),
45/18
1(no
bedshare)
Adjuste
dOR(95%
CI):1.5
0(1.12
to2.37)
Exclu
siveb
reastfeeding
rate
onem
onth
priortointerview.
Only20.3%of
study
infants
were<1m
oof
age—
datafor
thissubgroup
isno
tkno
wn.
Lossto
follo
wup
was<5%
8Mollborgetal.
2011/Sweden
[18]
Cross-sectionalstudy,
popu
latio
nbased
Rand
omlyselected
families
with
infants
who
hadreached6
mon
thso
fage
Question
naire
based
survey
on8176
families
Bedshare
Breastfeedingrate=544/2035
(bed
share),
159/2167
(nobedshare)
Adjuste
dOR(95%
CI):1.9
4(1.56to
2.41)
Any
breastfeeding(not
exclu
siveb
reastfeeding
)at6
mon
thso
fage.L
ossto
follo
wup
was
31.5%
6 International Journal of Pediatrics
Table2:Observatio
nalstudies
onbedsharea
ndSIDS.
S.no
.Stud
yID
/cou
ntry
Design,
setting
Stud
ypo
pulatio
nNum
bero
fsub
jects
Interventio
n/expo
sure
Outcome
Com
ments
1Klono
ff-Coh
enandEd
elstein
1995/U
SA[19
]
Case-con
trolstudy,
popu
latio
nbased
Cases:allinfantsfro
mbirthto
1yearo
fage
died
ofSIDS;controls:
matched
forb
irth
hospita
l,sex,race,dateo
fbirth,andthes
ames
urvey
Cases,200
Con
trols,
200
Bedshare
SIDSrate=60/200
(case),52/200(con
trol)
Noseparatedataforn
eonates.
Thes
tudy
repo
rted
theo
ddsfor
bedsharingdu
ringthed
aytim
ealso
(wed
idno
tuse
thatdata).
ORadjuste
dforp
assiv
esmok
ing.
Lossto
follo
wup
was
25%
2Broo
keetal.
1997/Scotland
[20]
Case-con
trolstudy,
popu
latio
nbased
Cases:allinfantd
eaths
occurringfro
m7thdayof
lifeto1y
ear;controls:
births
immediatelybefore
andaft
ertheind
excase
inthes
amem
aternityun
itandmatched
forthe
same
survey
Cases,146
Con
trols,
275
Bed-share
SIDSrate=11/14
6(case),
6/275(con
trol)
Noseparatedataforn
eonates
available.Other
factorsstudied,
GA≤36
wks,B
W<2500
g.Lo
ssto
follo
wup
was
25%
3L’H
oire
tal.
1998/Th
eNetherla
nds[21]
Case-con
trolstudy,
popu
latio
nbased
Cases:allsud
dendeaths
from
7days
to2yearso
fage;controls:
matched
for
dateof
birthandthes
ame
survey
Cases,73
Con
trols,
146
Bed-share
SIDSrate=6/73
(case),
7/146(con
trol)
Out
of73
SIDS,on
ly10
happ
ened
durin
gthen
eonatalp
eriod.
Other
factorsstudied:smok
ing,
alcoho
l.Datap
rovidedfor
infantsw
howeren
otexpo
sedto
passives
mok
ing
4Blaire
tal.
1999/U
nited
Kingdo
m[22]
Case-con
trolstudy,
popu
latio
nbased
Cases:allu
nexp
ected
deaths
upto
2yearso
fage;controls:
infantsb
orn
immediatelybefore
and
after
theind
excase
and
matched
forthe
same
survey
Cases,321
Con
trols,
1299
Bed-share
SIDSrate=82/321
(case),189/12
99(con
trol)
Separatedataforn
eonatesn
otavailable.Other
factorsstudied:
smok
ing,alcoho
l.Only2
3infants
died
between7and60
days
oflife
5Arnestadetal.
2001/N
orway
[23]
Case-con
trolstudy,
popu
latio
nbased
Cases:allsud
dendeaths
amon
gchild
renbetween
the2
ndweekand3y
rsof
age;controls:
infants
matched
forsex
anddate
ofbirth,rand
omlypicked
from
then
ationalregister
andmatched
forthe
same
survey
Cases,174
Con
trols,
375
Bed-share
SIDSrate=15/17
4(case),
24/375
(con
trol)
Noseparatedataforn
eonates
available(ou
tof174
cases,on
ly13
died
before
2mon
thso
fage).
Other
factorsstudied:smok
ing,
breastfeeding,birthordera
ndweight,mod
eofsleeping,
dummyuse,andsocioecono
mic
factors.Ad
juste
dforp
assiv
esm
oking.Lo
ssto
followup
was
31%(case)and25%(con
trol)
International Journal of Pediatrics 7
Table2:Con
tinued.
S.no
.Stud
yID
/cou
ntry
Design,
setting
Stud
ypo
pulatio
nNum
bero
fsub
jects
Interventio
n/expo
sure
Outcome
Com
ments
6Williamse
tal.
2002/N
ewZe
aland[24]
Case-con
trolstudy,
popu
latio
nbased
Cases:allu
nexp
ected
infant
deaths
from
29days
to1y
earo
fage;con
trols:
rand
omlyselected
from
allbirths,excepth
ome
births,and
matched
for
thes
ames
urvey
Cases,369
Con
trols,
1558
Bed-share
SIDSrate=86/369
(case),162/15
58(con
trol)
Noseparatedataforn
eonates
available.Other
factorsstudied:
smok
ing,breastfeeding.Be
dsharingrefersto
“usual”
patte
rnor
lastnight’ssle
episno
tkno
wn.
Lossto
follo
wup
was
10–19%
7Carpenter
etal.
2004/Europ
e[25]
Case-con
trolstudy,
popu
latio
nbased
Cases:allu
nexplained
deaths
inthefi
rstyearo
flife;controls:
rand
omly
selected
from
theb
irth
records,matched
fora
geandthes
ames
urvey
Cases,281
Con
trols,
1760
Bed-share
SIDSrate=32/281
(case),139/17
60(con
trol)
Ofthe
total700
oddcases,on
ly57
SIDSoccurred
inthefi
rst
mon
thof
life.Other
factors
studied:smok
ing,alcoho
l.Inform
ationdepicted
here
isfor
infantsw
hose
mothersdidno
tsm
oke
8Bu
bnaitie
neetal.2005/
Lithuania[
26]
Case-con
trolstudy,
popu
latio
nbased
Cases:inclu
ded<1y
earo
fageg
roup
died
ofSIDS;
controls:
matched
ford
ate
ofbirth,region
,and
the
sames
urvey
Cases,35
Con
trols,
145
Bed-share
SIDSrate=0/35
(case),
20/14
5(con
trol)
Noseparatedataforn
eonates
available(on
ly1S
IDSdu
ringthe
neon
atalperio
d).Studied
subgroup
s,GA≤36
wks,B
W<2
500g
.Losstofollo
wup
was
22.2%in
cases
9McG
arveyetal.
2006/Ir
eland
[27]
Case-con
trolstudy,
popu
latio
nbased
Cases:allinfantsfro
mbirthto
1yearo
fage
died
ofSIDS;controls:
matched
ford
ateo
fbirth,
commun
ityarea,and
the
sames
urvey
Cases,259
Con
trols,
829
Bed-share
SIDSrate=128/259
(case),101/829
(con
trol)
Datap
rovidedisforinfantsaged
<10
weeks
ofage.Other
factors
studied:smok
ing,alcoho
l.Lo
ssto
follo
wup
was
14%
10
Ruys
etal.
2007/Th
eNetherla
nds
[28]
Case-con
trolstudy,
popu
latio
nbased
Cases:allinfants<6
mon
thso
fage
died
ofcot
deaths;con
trols:
infantso
fthes
amea
gegrou
pswho
participated
ina
coun
tryw
ides
urvey
Cases,138
Con
trols,
1628
Bed-share
SIDSrate=36/13
8(case),151/16
28(con
trol)
Noseparatedataforn
eonates
available.Other
factorsstudied:
smok
ing,breastfeeding.
Adjuste
dforb
reastfeeding
,age,
andpassives
mok
ing
11Blaire
tal.
2009/Eng
land
[9]
Case-con
trolstudy,
popu
latio
nbased
Cases:allu
nexp
ected
deaths
upto
2yearso
fage;controls:
from
the
maternitydatabase
ofon
eho
spita
land
matched
for
thes
ames
urvey
Cases,79
Con
trols,
87Be
d-share
SIDSrate=30/79(case),
17/87(con
trol)
Other
factorsstudied:smok
ing,
narcotics,GA≤37
wks,B
W<
2500
g.Neonatesa
ccou
nted
for
only15%of
SIDS.Lo
ssto
follo
wup
was
5–14%in
both
the
grou
ps
8 International Journal of Pediatrics
Table2:Con
tinued.
S.no
.Stud
yID
/cou
ntry
Design,
setting
Stud
ypo
pulatio
nNum
bero
fsub
jects
Interventio
n/expo
sure
Outcome
Com
ments
12
Venn
emann
etal.
2009/G
ermany
[29]
Case-con
trolstudy,
popu
latio
nbased
Cases:allinfantsfro
mbirthto
1yearo
fage
died
ofSIDS;controls:
matched
ford
ateo
fbirth
andthes
ames
urvey
Cases,333
Con
trols,
998
Bed-share
SIDSrate=27/333
(case),28/998(con
trol)
Datap
rovidedisforinfantsaged
<13
weeks
ofage.Other
factors
studied:smok
ing,GA≤37
wks,
BW<1500
g.Ad
juste
dfor
maternalsmok
ing.Lo
ssto
follo
wup
was
18–4
2%in
both
the
grou
ps
13Fu
etal.
2010/U
SA[30]
Case-con
trolstudy,
popu
latio
nbased
Cases:allinfantsfro
mbirthto
1yearo
fage
died
ofSIDS:controls:
matched
forb
irth,race,
age,birthweight,andthe
sames
urvey
Cases,195
Con
trols,
194
Bed-share
SIDSrate=15/19
5(case),
6/194(con
trol)
Repo
rted
datafor3
subgroup
s:<1m
o,1–3m
o,and>4m
o;on
lythe1stmon
thdatahasb
eenused
here.O
ther
factorsstudied:
smok
ing,alcoho
l.Be
dsharing
inclu
dedsle
epingon
them
attre
ssas
wellassofa.Lo
ssto
follo
wup
was
25%
International Journal of Pediatrics 9
Table3:Qualityassessmento
fincludedstu
dies
usingtheN
ewCa
stleOtta
waS
cale.
Stud
yauthor,
year,cou
ntry
Selection
Com
parabilityof
cases
andcontrolson
the
basis
ofthed
esignor
analysis
Expo
sure
Com
ment
Isthec
ase
defin
ition
adequate?
Representativ
eness
ofthec
ases
Selectionof
controls
Definitio
nof
controls
Ascertainm
ento
fexpo
sure
Thes
ame
metho
dof
ascertain-
mento
fcases
andcontrols
Non
respon
serate
Carpenter
etal.200
4,Eu
rope
[25]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,infantsm
atched
fora
geandthes
ame
survey
area,rando
mly
selected
from
the
birthrecords(∗
)
Yes,grou
pscomparable
andalso
adjuste
dfor
mostp
otentia
lconfou
nders(∗∗
)
Yes,interviews(∗
)Yes(∗
)Described
(∗)Goo
dqu
ality
Blaire
tal.
1999,U
nited
Kingdo
m[22]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,infantsb
orn
immediatelybefore
andaft
ertheind
excase
(∗)
Yes,grou
pscomparable
andalso
adjuste
dfor
mostp
otentia
lconfou
nders(∗∗
)
Yes,interviews(∗
)Yes(∗
)Described
(∗)Goo
dqu
ality
Arnestadetal.
2001,N
orway
[23]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,infantsm
atched
forsex
anddateof
birth,rand
omly
picked
from
the
natio
nalregister
(∗)
Yes,grou
pscomparable
andalso
adjuste
dfor
mostp
otentia
lconfou
nders(∗∗
)
Yes,mailed
questio
nnaire
(∗)
Yes(∗
)
Described,
31%and25%
lossforthe
casesa
ndcontrols,
respectiv
ely(∗)
Goo
dqu
ality
Bubn
aitie
neet
al.2005,
Lithuania[
26]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,infantsm
atched
ford
ateo
fbirthand
region
,rando
mly
picked
(∗)
Yes,grou
pscomparable.Not
adjuste
dform
ost
potentialcon
foun
ders
(∗)
Yes,ho
mev
isitsin
casesa
ndmailed
questio
nnaire
incontrols(∗)
No
Described
onlyforthe
cases,22.2%
loss(∗)
Goo
dqu
ality
Ruys
etal.
2007,Th
eNetherla
nds
[28]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,infantsw
hoparticipated
inanothersurvey(∗)
No,grou
psno
tcomparable.Ad
juste
dform
ostp
otentia
lconfou
nders(∗
)
Yes,ho
mev
isitsand
directinterviewin
casesa
nddirect
interviewin
controls
(∗)
Yes(∗
)Not
describ
edGoo
dqu
ality
McG
arveyet
al.2006,
Ireland[27]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,infantsm
atched
ford
ateo
fbirthand
popu
latio
nbased
area,rando
mlypicked
from
birthregiste
r(∗
)
Yes,grou
pscomparable
andalso
adjuste
dfor
mostp
otentia
lconfou
nders(∗∗
)
Yes,ho
meinterview
inbo
thcasesa
ndcontrols(∗)
Yes(∗
)Described,
14%loss(∗)
Goo
dqu
ality
Fuetal.2010,
USA
[30]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,infantsm
atched
forb
irthrace,age,
andbirthweight,
rand
omlypicked
from
birthregiste
r(∗
)
Yes,grou
pscomparable.Not
adjuste
dform
ost
potentialcon
foun
ders
(∗)
Yes,ho
mev
isitsand
directinterviewin
casesa
nddirect
interviewin
controls
(∗)
Yes(∗
)Described,
25%loss(∗)
Goo
dqu
ality
10 International Journal of Pediatrics
Table3:Con
tinued.
Stud
yauthor,
year,cou
ntry
Selection
Com
parabilityof
cases
andcontrolson
the
basis
ofthed
esignor
analysis
Expo
sure
Com
ment
Isthec
ase
defin
ition
adequate?
Representativ
eness
ofthec
ases
Selectionof
controls
Definitio
nof
controls
Ascertainm
ento
fexpo
sure
Thes
ame
metho
dof
ascertain-
mento
fcases
andcontrols
Non
respon
serate
Klono
ff-Coh
enand
Edels
tein
1995,
USA
[19]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,infantsm
atched
forb
irthho
spita
l,sex,
race,and
dateofbirth,
rand
omlypicked
from
birthregiste
r(∗
)
Yes,grou
pscomparable
andalso
adjuste
dfor
mostp
otentia
lconfou
nders(∗∗
)
Yes,teleph
onic
interviewin
cases
andcontrols(∗)
Yes(∗
)Described,
25%loss(∗)
Goo
dqu
ality
Blaire
tal.
2009/Eng
land
[9]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,fro
mthe
maternitydatabase
ofho
spita
l(∗
)
No,grou
psno
tcomparable.Not
adjuste
dform
ost
potentialcon
foun
ders
Yes,ho
mev
isitsand
questio
nnaire
incasesa
ndqu
estio
nnaire
incontrols(∗)
No
Described,
5–14%lossin
thetwo
grou
ps(∗)
Goo
dqu
ality
Venn
emann
etal.200
9,Germany[29]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,matched
fora
ge,
gend
er,region,
and
sleep
time(∗
)
Yes,grou
pscomparable
andalso
adjuste
dfor
mostp
otentia
lconfou
nders(∗∗
)
Yes,ho
mev
isitsand
questio
nnaire
incasesa
ndcontrols
(∗)
Yes(∗
)
Described,
18–4
2%loss
inthetwo
grou
ps(∗)
Goo
dqu
ality
L’Hoire
tal.
1998,Th
eNetherla
nds
[21]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,matched
ford
ate
ofbirth(∗)
No,grou
psno
tcomparable.Not
adjuste
dform
ost
potentialcon
foun
ders
Yes,ho
mev
isitsand
questio
nnaire
incasesa
ndcontrols
(∗)
Yes(∗
)Not
describ
edGoo
dqu
ality
Broo
keetal.
1997,Scotland
[20]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,matched
fora
ge,
season
,and
maternity
unit(∗)
Yes,grou
pscomparable
andalso
adjuste
dfor
mostp
otentia
lconfou
nders(∗∗
)
Yes,ho
mev
isitsand
questio
nnaire
incasesa
ndcontrols
(∗)
Yes(∗
)Described,
∼25%loss(∗)Goo
dqu
ality
Flem
ing1996,
England
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,infantsb
orn
immediatelybefore
andaft
ertheind
excase
(∗)
Yes,grou
pscomparable
andalso
adjuste
dfor
mostp
otentia
lconfou
nders(∗∗
)
Yes,ho
mev
isitsand
questio
nnaire
incasesa
ndcontrols
(∗)
Yes(∗
)Described,
∼9%
loss(∗)
Goo
dqu
ality
Williamse
tal.
2002,N
ewZe
aland[24]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,rand
omly
selected
from
all
births,excepth
ome
births
(∗)
No,grou
psno
tcomparablea
ndalso
adjuste
dform
ost
potentialcon
foun
ders
(∗)
Yes,interviewbased
incasesa
ndcontrols
(∗)
Yes(∗
)Described,
10–19%
loss
(∗)
Goo
dqu
ality
Ball2003,
United
Kingdo
m[12]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,healthyinfants
andmothers,
delivered
at36+
weeks.Followed
uptill4
mon
thso
fage
(∗)
Yes,grou
pscomparable.Not
adjuste
dform
ost
potentialcon
foun
ders
(∗)
Yes,sle
eplogs
were
used
tomeasure
the
expo
sure
status
(∗)
Yes(∗
)Described,
∼40
%loss(∗)Goo
dqu
ality
International Journal of Pediatrics 11
Table3:Con
tinued.
Stud
yauthor,
year,cou
ntry
Selection
Com
parabilityof
cases
andcontrolson
the
basis
ofthed
esignor
analysis
Expo
sure
Com
ment
Isthec
ase
defin
ition
adequate?
Representativ
eness
ofthec
ases
Selectionof
controls
Definitio
nof
controls
Ascertainm
ento
fexpo
sure
Thes
ame
metho
dof
ascertain-
mento
fcases
andcontrols
Non
respon
serate
McC
oyetal.
2004,U
SA[14
]Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,follo
wup
ofinfantsb
ornat
selected
study
hospita
ls(∗)
Yes,grou
pscomparable
andalso
adjuste
dfor
mostp
otentia
lconfou
nders(∗∗
)
Yes,mailed
questio
nnaire
(∗)
Yes(∗
)Described,
∼30%loss(∗)Goo
dqu
ality
Lahr
etal.
2007,
USA
[15]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,str
atified
sample
draw
neach
mon
thfro
mrecentlyfiled
birthcertificates
(∗)
Yes,grou
pscomparable.Not
adjuste
dform
ost
potentialcon
foun
ders
(∗)
Question
naire
based
(∗)
Yes(∗
)Described,
26.5%loss(∗)Goo
dqu
ality
Tan2011,
Malaysia
[17]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,controls
attend
inghealth
facility(∗)
Yes,infantsu
pto
6mon
thsa
ttend
ing
health
clinics
(∗)
Yes,grou
pscomparable
andalso
adjuste
dfor
mostp
otentia
lconfou
nders(∗∗
)
Face-to
-face
interviewsu
singa
pretestedstr
uctured
questio
nnaire
(∗)
Yes(∗
)Described,
<5%
loss(∗)
Goo
dqu
ality
Mollborgetal.
2011,Sweden
[18]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,rand
omly
selected
families
with
infantsw
hohad
reached6mon
thso
fage
(∗)
Yes,grou
pscomparable
andalso
adjuste
dfor
mostp
otentia
lconfou
nders(∗∗
)
Yes,mailed
questio
nnaire
(∗)
Yes(∗
)Described,
31.5%loss(∗)
Goo
dqu
ality
Flicketal.
2001,U
SA[11]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,pregnant
wom
enenrolledat28
wk,
contactedatarou
nd8
weeks
after
delivery
(∗)
Yes,grou
pscomparable.Not
adjuste
dform
ost
potentialcon
foun
ders
(∗)
Yes,mailed
questio
nnaire
(∗)
Yes(∗
)Described,
2.2%
loss(∗)
Goo
dqu
ality
Blaira
ndBa
ll2004,U
nited
Kingdo
m[13]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,healthynewbo
rninfantsa
ndmothers
atho
me(∗
)
Yes,grou
pscomparable.Not
adjuste
dform
ost
potentialcon
foun
ders
(∗)
Yes,sle
eplogs
and
interviews(∗
)Yes(∗
)Described,
<20%loss(∗)Goo
dqu
ality
Blaire
tal.
2010,U
nited
Kingdo
m[16]
Yes,record
valid
ation(∗)
Yes,obviou
slyrepresentativ
eserie
sofcases
(∗)
Yes,commun
itycontrols(∗)
Yes,infantso
fall
pregnant
women
resid
ingin
the3
health
distric
tsof
Avon
;age
grou
p:birthto
4years
(∗)
Yes,grou
pscomparable.Not
adjuste
dform
ost
potentialcon
foun
ders
(∗)
Yes,mailed
questio
nnaire
(∗)
Yes(∗
)Described,
∼50%loss(∗)Goo
dqu
ality
∗
One
point,∗∗
twopo
ints.
12 International Journal of Pediatrics
Blair and Ball 2004
Study
McCoy et al. 2004
ID
3.09 (2.67, 3.58)
6.60 (3.29, 14.70)
3.00 (2.60, 3.50)
ES (95% CI)
100.00
3.79
96.21
Weight (%)
0.068 1 14.7
Overall (I2 = 75.6%, P = 0.043)
Figure 2: Forest plot: bed share and breastfeeding.
Heterogeneity between groups
Last night
ID
Vennemann et al. 2009Carpenter et al. 2004
McGarvey et al. 2006
Blair et al. 2009
Bubnaitiene et al. 2005
Blair et al. 1999
Ruys et al. 2007
Williams et al. 2002
Study
Routine
L’Hoir et al. 1998Klonoff-Cohen and Edelstein 1995
Brooke et al. 1997
Fu et al. 2010
Arnestad et al. 2001
2.36 (1.97, 2.83)
ES (95% CI)
2.51 (1.95, 3.23)
2.71 (1.44, 5.10)1.56 (0.91, 2.68)
3.53 (1.40, 8.93)
2.52 (1.19, 5.42)
0.09 (0.01, 1.60)
9.78 (4.02, 23.80)
2.73 (1.34, 5.55)
2.62 (1.93, 3.53)2.22 (1.71, 2.87)
1.78 (0.47, 6.43)1.21 (0.59, 2.48)
2.90 (0.75, 11.30)
2.00 (1.20, 3.40)
1.66 (0.57, 4.85)
100.00
Weight (%)
51.18
8.1211.13
3.78
5.65
0.42
4.10
6.43
35.6148.82
1.906.30
1.76
11.97
2.83
0.006 1 167
(P= 0.499)
Subtotal (I2 = 47.4%, P = 0.091)
Subtotal (I2 = 55.0%, P = 0.038)
Overall (I2 = 48.5%, P = 0.025)
Figure 3: Forest plot: bed share and SIDS.
3.09; 95% CI (2.67, 3.58); 𝐼2 = 75.6%; Figure 2). Since all wereobservational studies, the quality of evidence as assessed byGRADE criteria was found to be low (Table 4).
3.2. SIDS. All except one study that evaluated the associationbetween bed sharing and SIDS were from developed coun-tries [26]. The attrition rate varied from 2.2% to 50% in allbut two studies where it was unclear [21, 27].The attrition ratefor both the groupswas calculated separately by percentage ofthose who responded to the total questionnaires distributedfor each group. Five studies reported routine or usual bedsharing [9, 12, 20, 26, 28], whereas; rest reported bed sharingon a particular night (last sleep for cases and referencesleep for controls).When we separately studied routine/usual
versus last/reference sleep bed sharing, we found similarincrease in risk (Figure 3). This means that pattern of bedsharing does not affect the SIDS risk. More than half of thestudies showed significant association between bed sharingand SIDS in the enrolled infants (Table 2). Pooled analysis ofall 13 studies demonstrated 2.4-fold odds of being exposed tobed share in those who die of SIDS compared to the controls(aOR 2.36; 95% CI (1.97, 2.83); 𝐼2 = 48.5%; Figure 3). Giventhat all were observational studies, the quality of evidence asassessed by GRADE criteria was found to be low (Table 4).
3.3. Secondary Outcomes. None of the included studies hadreported the incidence of hypothermia or sepsis, NMR,among the enrolled infants.
International Journal of Pediatrics 13
Table4:GRA
DEevidence
tablefor
assessmento
fbed
sharev
ersusn
obedsharefor
neon
ates.
Qualityassessment
Summaryof
finding
s
Participants
(studies)
Follo
wup
Risk
ofbias
Inconsistency
Indirectness
Imprecision
Publication
bias
Overall
quality
ofevidence
Stud
yeventrates
(%)
Relativ
eeffect
(95%
CI)
Anticipated
absoluteeffects
With
nobedshare
With
bedshare
Risk
with
nobedshare
Risk
difference
with
bedshare
(95%
CI)
Sudd
eninfant
deathsynd
rome(criticaloutcome,assessed
with
interviewbased)
13072
(14stu
dies)
0–2years
Serio
us1
Noserio
usinconsistency
Serio
usNoserio
usim
precision
Und
etected
⊕⊝⊝⊝VER
YLO
W1du
eto
riskof
bias,
indirectness
1148/10274
(11.2
%)
697/2798
(24.9%
)OR2.41
(2.02
to2.88)
Stud
ypo
pulatio
n
112SIDSper
1000
121m
ore
SIDSper
1000
(from
91moreto154
more)
Mod
erate
—Breastfeeding(criticalou
tcom
e,assessed
with
interviewbased)
1066
6(8
studies)
1–12
mon
ths
Serio
usSerio
usSerio
usNoserio
usim
precision
Und
etected
⊕⊝⊝⊝VER
YLO
Wdu
eto
riskof
bias,
inconsis-
tency,
indirectness,
andlarge
effect
4255/8511
(50%
)1419/2155
(65.8%
)OR3.09
(2.67to
3.58)
Stud
ypo
pulatio
n
500BF
per
1000
256moreB
Fper100
0(fr
om228
moreto282
more)
Mod
erate
—1
Unclear
inmosto
fthe
studies.
14 International Journal of Pediatrics
4. Discussion
“Bed sharing” has been commonly used interchangeably withterms like “bedding-in” or “cosleeping.” “Bed sharing” is atopic of common interest in regard to its controversial associ-ationwith sudden infant death syndrome (SIDS) on one handand breastfeeding on the other hand.There are many reasonsthat make parents prefer bed sharing with their infants, suchas ease in breastfeeding, enjoying the time spent with theinfant, comforting the infant in case he gets fussy, and to puthim to sleep, attending the infant quickly in case of anymishap or during any illness, promoting love, affection, orbonding, and so forth [12].
Breastfeeding has been proposed to be one of the mostprominent reasons for bed sharing. But studies have founddifficulties in establishing whether successful breastfeedingleads to bed sharing or bed sharing is because of breastfeed-ing. Based on the demographic and health surveys conductedbetween years 2002 and 2008, WHO presented data onindicators assessing infant feeding practices for 46 countries[31]. The data showed that breastfeeding rates are the highestin early infancy, which is also the timewith the highest preva-lence of bed sharing. In a systematic review based on cross-sectional studies in infancy beyond the neonatal period theauthors found a positive correlation between bed sharing andbreastfeeding [32]. However, in a longitudinal study a two-way, complex, interdependent, and temporal relationship wasfound which was itself insufficient to distinguish the inde-pendent role of bed sharing in breastfeeding [16]. A commonperception is that mothers who breastfeed commonly alsobed share frequently in order to avoid any interruption inbreastfeeding at night.
The present systematic review demonstrates significantlyassociation between bed sharing during the neonatal periodand breastfeeding at 4–6 weeks of age and at 6 month of age.Admittedly, the quality of evidence was low. Although thedata generated from observational studies are of low quality,observational studies are still the most common source ofinformation available to SIDS researchers. The studies werealso heterogeneous, but we could not carry out either sub-group or metaregression analyses to investigate the cause ofheterogeneity because of the small number of studies.
The AAP task force on SIDS recommends that bedsharing should be avoided when the infant is younger than3 months irrespective of parents smoking status. They alsodescribe that breastfeeding is associatedwith a reduced risk ofSIDS, and if possible, mothers should exclusively breastfeedfor 6 months as per the recommendations of the AAP [33].These statements are perplexing andmight be difficult for theparents to follow.
4.1. Comparison with the Existing Literature. A recently donemeta-analysis on relationship between bed sharing and SIDSincluded case-control studies with predefined criteria (anadequate definition for SIDS; autopsies performed in >95%of cases; an appropriate description of SIDS ascertainmentin the study population; a clear description of the processof control selection; and sufficient data to calculate ORs and95% CIs or the actual ORs and 95% CIs were provided) [34].
The combined OR for SIDS in all bed share versus nonbedshare infants was 2.89 (95% CI 1.99, 4.18). The risk was thehighest when maternal smoking was present (OR, 6.27 (95%CI 3.94, 9.99)), and the infant was <12 weeks old (OR, 10.37(95% CI 4.44, 24.21)). In this meta-analysis bed sharing asan exposure was studied at any time period during infancyand included both routine as well as last night bed share.In contrast, we studied bed sharing as an exposure startingduring the neonatal period and continued thereafter for avariable time period. Besides this, we also studied breast-feeding simultaneously whichwas not done in the abovemen-tioned meta-analysis.
The included studies in presentmeta-analysis consistentlyaimed to identify the prevalence of known or potential riskfactors for SIDS. Three studies more specifically aimed toinvestigated bed sharing and SIDS [19, 27, 28]. One study [30]reported bed sharing including those sleeping on themattressas well as sofa, while another studied bed sharing duringthe daytime also (this was not used in the present review)[19]. Definitions of sleeping location, whether bed sharingor nonbed sharing, were heterogeneous. For the outcome ofSIDS, the most frequently investigated interaction with bedsharing was smoking (most commonly by the mother eitherduring pregnancy or postpartum).We reported the outcomesafter adjusting for smoking. An important point that needsmentioned here is that none of the studies reviewed distin-guish between planned and accidental bed sharing, a featurethat is probably one of the biggest factors involved in thestudies identifying an increased risk of this practice.
Only one study from developing country was included inthe presentmeta-analysis [26].This study reported rate of bedsharing to be 14% in the control subjects, while the SIDS ratein the country was low (0.3 per 1000 live births). Asian coun-tries like Japan and China, though developed, have a lowerrate of SIDSdespite a higher rate of bed sharing [35, 36]. A bedsharing rate of 37% was reported in Japan in year 2006 whenthe rate of SIDSwas only 0.16 per 1000 live births, and the cor-responding figures in China were 24% and 0.16, respectively,during year 2002. Considering these figures, a general rec-ommendation of restricted bed sharing might not be appro-priate for developing (including Asian) countries in contrastto developed countries where other known risk factors mightplay important role.
Published studies from developing countries and partic-ularly fromAsian community show a low rate of SIDS in spiteof a higher rate of bed sharing.This lower prevalence of SIDSis whether due to the protective effect of breastfeeding or isjust a reflection of the demographic that chooses breastfeed-ing is a matter of debate. One study supported these findingsand showed that exclusive breastfeeding at 1 month of agehalved the risk, and even partial breastfeeding at 1 month ofage reduced the risk [37]. They also found a high incidenceof SIDS below 6 months age, and based on these findingsthey recommended that breastfeeding should be continueduntil at least 6 months of age when the risk of SIDS dimin-ishes. A recent meta-analysis including 18 studies showedthat breastfeeding is protective against SIDS, and this effect isstronger when breastfeeding is exclusive [38]. While both thestudies identified a direct protective effect of breastfeeding on
International Journal of Pediatrics 15
SIDS, neither of them examined the impact of bed sharing onthe individual outcomes. But studies examining the risk fac-tors for SIDS have found the risk of bed sharing to be so pro-found that the protective effect of breastfeeding did not sig-nificantly influence the magnitude of the risk associated withbed sharing [39–41]. This has been hypothesized to be due tothe lifestyle and socioeconomic class that decides both breast-feeding and SIDS rates supported by findings from developedversus developing or Asian countries [40, 42]. Finally, it isactually difficult to isolate breastfeeding and bed sharing fromother risk factors related to SIDS.
We did not find any relevant studies, with a contem-poraneous comparison, examining the effect of bed sharingin relation to other outcomes of interest (the incidence/prevalence of hypothermia, mortality, and sepsis rate in bedsharing neonates or infants).
4.2. Strengths and Weaknesses of Review. The strength ofpresent systematic review is that it included studies havingexposure to bed share during neonatal period (and continuedthereafter) and addressed both the benefits (breastfeeding)and risks (of SIDS) of bed sharing. But there are somepotential limitations that merit attention: (a) methodologicalissues: all the studies were observational and were conductedmostly in developed country settings; the age group includedfrom the neonatal period and up to 2 years of age, thusmaking it difficult to generalize the result (as SIDS is meantfor during infancy only); the control groups were alsovariably defined in all the studies (as shown in Table 2); (b)dramatic change in SIDS epidemiology during the last decade[43]; (c) since we included only studies having exposureto bed share during neonatal period and excluded thosehaving exposure during last sleep only, our results cannotbe generalized to SIDS as a whole in infancy, as last nightbed sharing that happened after the neonatal period hasnot been captured in our review. Also, we were not able toevaluate the “net” beneficial effect of the intervention as noneof the studies had reported both breastfeeding and SIDS ratestogether.
4.3. Further Area of Research. A total of 21 observationalstudies (breastfeeding and bed sharing = 8; SIDS and bedsharing = 13) were included in the present review. None ofthe studies reported both the primary outcomes (SIDS andbreastfeeding) in bed sharing population, so we were notable to evaluate the “net” effect of bed sharing. Most of theincluded studies were undertaken more than a decade ago,and the prevalence of bed sharing might have changed asa result of guideline recommendations or societal factors.Bed sharing is a well-known cultural practice in developingcountries, but only one study was found to be eligible forinclusion in the review. Control groups were also variablydefined in all the included studies. Because prospectivestudies of SIDS are not possible given the now rarity of thesedeaths, more detailed retrospective studies that look at bedsharing, breastfeeding, and the hazardous circumstances thatput babies at risk are needed.
5. Conclusion
There is low quality evidence that bed sharing is associatedwith higher breastfeeding rates at 4 weeks of age andincreased risk of SIDS irrespective of maternal smoking. Dueto paucity of studies, it is difficult to predict whether neonatesare at a more risk than older infants (>1 month age). We needmore detailed studies that look at bed sharing, breastfeedingand hazardous circumstance that put babies at risk.
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper.
Acknowledgments
WorldHealthOrganization (WHO) provided funding for theconduction of systematic reviews so as to formulate certainguidelines and to make policy on issues related to newbornhealth. As a part of this incentive, a systematic review wasconducted on the safety and efficacy of “bed share” during theneonatal period.The funder had no role in study design, datacollection and analysis, decision to publish, or preparation ofthe paper.
References
[1] B. Buranasin, “The effects of rooming-in on the success ofbreastfeeding and the decline in abandonment of children,”Asia-Pacific Journal of Public Health, vol. 5, no. 3, pp. 217–220,1991.
[2] World Health Organization, “Evidence for the ten steps tosuccessful breastfeeding,” Geneva, Switzerland, World HealthOrganization, 1998, http://www.who.int/maternal child ado-lescent/documents/9241591544/en/.
[3] S. Nakamura, M. Wind, and M. A. Danello, “Review of hazardsassociated with children placed in adult beds,” Archives ofPediatrics and Adolescent Medicine, vol. 153, no. 10, pp. 1019–1023, 1999.
[4] D. A. Drago and A. L. Dannenberg, “Infant mechanical suffoca-tion deaths in the United States, 1980–1997,” Pediatrics, vol. 103,no. 5, article e59, 1999.
[5] R. W. Byard, “Is breast feeding in bed always a safe practice?”Journal of Paediatrics and Child Health, vol. 34, no. 5, pp. 418–419, 1998.
[6] K. D. Rosenberg, “Sudden infant death syndrome and Co-sleeping,” Archives of Pediatrics and Adolescent Medicine, vol.154, no. 5, pp. 529–530, 2000.
[7] H. L. Ball, P. S. Blair, and M. P. Ward-Platt, ““New” practice ofbedsharing and risk of SIDS,” The Lancet, vol. 363, no. 9420,article 1558, 2004.
[8] M. O’Hara, R. Harruff, J. E. Smialek, and D. R. Fowler, “Sleeplocation and suffocation: how good is the evidence?” Pediatrics,vol. 105, no. 4, pp. 915–917, 2000.
[9] P. S. Blair, P. Sidebotham, C. Evason-Coombe, M. Edmonds, E.M. A. Heckstall-Smith, and P. Fleming, “Hazardous cosleepingenvironments and risk factors amenable to change: case-controlstudy of SIDS in south west England,” British Medical Journal,vol. 339, Article ID b3666, 2009.
16 International Journal of Pediatrics
[10] “Newcastle-Ottawa Quality Assessment Scale: case controlstudies,” http://www.ohri.ca/programs/clinical epidemiology/oxford.htm.
[11] L. Flick,D. K.White, C.Vemulapalli, B. B. Stulac, and J. S. Kemp,“Sleep position and the use of soft bedding during bed sharingamong African American infants at increased risk for suddeninfant death syndrome,” Journal of Pediatrics, vol. 138, no. 3, pp.338–343, 2001.
[12] H. L. Ball, “Breastfeeding, bed-sharing, and infant sleep,” Birth,vol. 30, no. 3, pp. 181–188, 2003.
[13] P. S. Blair and H. L. Ball, “The prevalence and characteristicsassociated with parent-infant bed-sharing in England,”Archivesof Disease in Childhood, vol. 89, no. 12, pp. 1106–1110, 2004.
[14] R. C. McCoy, C. E. Hunt, S. M. Lesko et al., “Frequency of bedsharing and its relationship to breastfeeding,” Journal of Devel-opmental and Behavioral Pediatrics, vol. 25, no. 3, pp. 141–149,2004.
[15] M. B. Lahr, K. D. Rosenberg, and J. A. Lapidus, “Maternal-infant bedsharing: risk factors for bedsharing in a population-based survey of new mothers and implications for SIDS riskreduction,”Maternal and Child Health Journal, vol. 11, no. 3, pp.277–286, 2007.
[16] P. S. Blair, J. Heron, and P. J. Fleming, “Relationship betweenbed sharing and breastfeeding: longitudinal, population-basedanalysis,” Pediatrics, vol. 126, no. 5, pp. e1119–e1126, 2010.
[17] K. L. Tan, “Factors associated with exclusive breastfeedingamong infants under six months of age in peninsular malaysia,”International Breastfeeding Journal, vol. 6, article 2, 2011.
[18] P.Mollborg,G.Wennergren, S.G.Norvenius, andB.Alm, “Bed-sharing among six-month-old infants in western Sweden,” ActaPaediatrica, vol. 100, no. 2, pp. 226–230, 2011.
[19] H. Klonoff-Cohen and S. L. Edelstein, “Bed sharing and thesudden infant death syndrome,” BritishMedical Journal, vol. 311,no. 7015, pp. 1269–1272, 1995.
[20] H. Brooke, A. Gibson, D. Tappin, and H. Brown, “Case-controlstudy of sudden infant death syndrome in Scotland, 1992–5,”British Medical Journal, vol. 314, no. 7093, pp. 1516–1520, 1997.
[21] M. P. L’Hoir, A. C. Engelberts, G. T. J. VanWell et al., “Case-con-trol study of current validity of previously described risk factorsfor SIDS in the Netherlands,” Archives of Disease in Childhood,vol. 79, no. 5, pp. 386–393, 1998.
[22] P. S. Blair, P. J. Fleming, I. J. Smith et al., “Babies sleeping withparents: case-control study of factors influencing the risk of thesudden infant death syndrome,”BritishMedical Journal, vol. 319,no. 7223, pp. 1457–1461, 1999.
[23] M. Arnestad, M. Andersen, A. Vege, and T. O. Rognum,“Changes in the epidemiological pattern of sudden infant deathsyndrome in southeast Norway, 1984–1998: implications forfuture prevention and research,” Archives of Disease in Child-hood, vol. 85, no. 2, pp. 108–115, 2001.
[24] S. M. Williams, E. A. Mitchell, and B. J. Taylor, “Are risk factorsfor sudden infant death syndrome different at night?” Archivesof Disease in Childhood, vol. 87, no. 4, pp. 274–278, 2002.
[25] R. G. Carpenter, L. M. Irgens, P. S. Blair et al., “Suddenunexplained infant death in 20 regions in Europe: case controlstudy,”The Lancet, vol. 363, no. 9404, pp. 185–191, 2004.
[26] V. Bubnaitiene, R. Kalediene, and R. Kevalas, “Case-controlstudy sudden infant death syndrome in Lithuania, 1997–2000,”BMC Pediatrics, vol. 5, article 41, 2005.
[27] C. McGarvey, M. McDonnell, K. Hamilton, M. O’Regan, and T.Matthews, “An 8 year study of risk factors for SIDS: bed-sharing
versus non-bed-sharing,” Archives of Disease in Childhood, vol.91, no. 4, pp. 318–323, 2006.
[28] J. H. Ruys, G. A. De Jonge, R. Brand, A. C. Engelberts, and B. A.Semmekrot, “Bed-sharing in the first four months of life: a riskfactor for sudden infant death,” Acta Paediatrica, vol. 96, no. 10,pp. 1399–1403, 2007.
[29] M. M. Vennemann, T. Bajanowski, B. Brinkmann, G. Jorch, C.Sauerland, and E. A. Mitchell, “Sleep environment risk factorsfor sudden infant death syndrome: the German sudden infantdeath syndrome study,” Pediatrics, vol. 123, no. 4, pp. 1162–1170,2009.
[30] L. Y. Fu, R. Y.Moon, and F. R. Hauck, “Bed sharing among blackinfants and sudden infant death syndrome: interactions withother known risk factors,”Academic Pediatrics, vol. 10, no. 6, pp.376–382, 2010.
[31] WHO, “Indicators for assessing infant and young child feedingpractices: part III Country Profiles,” http://www.who.int/nutri-tion/publications/infantfeeding/9789241599757/en/index.html.
[32] S. D. Buswell and D. L. Spatz, “Parent-infant co-sleeping and itsrelationship to breastfeeding,” Journal of Pediatric Health Care,vol. 21, no. 1, pp. 22–28, 2007.
[33] American Academy of Pediatrics, Section on Breastfeeding,“Breastfeeding and the use of human milk,” Pediatrics, vol. 115,pp. 496–506, 2005.
[34] M. M. Vennemann, H.-W. Hense, T. Bajanowski et al., “Bedsharing and the risk of sudden infant death syndrome: can weresolve the debate?” Journal of Pediatrics, vol. 160, no. 1, pp. 44–48, 2012.
[35] E. A. S. Nelson, K.-F. To, Y.-Y. Wong et al., “Hong Kong case-control study of sudden unexpected infant death,”New ZealandMedical Journal, vol. 118, no. 1227, Article ID U1788, 2005.
[36] SIDS Family Association Japan, “The SIDS Prevention Cam-paign,” 2012, http://www.sids.gr.jp/en/recent projects.html.
[37] M. M. Vennemann, T. Bajanowski, B. Brinkmann et al., “Doesbreastfeeding reduce the risk of sudden infant death syn-drome?” Pediatrics, vol. 123, no. 3, pp. e406–e410, 2009.
[38] F. R. Hauck, J. M. D. Thompson, K. O. Tanabe, R. Y. Moon, andM. M. Vennemann, “Breastfeeding and reduced risk of suddeninfant death syndrome: a meta-analysis,” Pediatrics, vol. 128, no.1, pp. 103–110, 2011.
[39] T. Horsley, T. Clifford, N. Barrowman et al., “Benefits and harmsassociated with the practice of bed sharing a systematic review,”Archives of Pediatrics andAdolescentMedicine, vol. 161, no. 3, pp.237–245, 2007.
[40] R. Y. Moon, R. A. Darnall, M. H. Goodstein et al., “SIDS andother sleep-related infant deaths: expansion of recommenda-tions for a safe infant sleeping environment,” Pediatrics, vol. 128,no. 5, pp. 1030–1039, 2011.
[41] C. E. Hunt and F. R. Hauck, “Sudden infant death syndrome,”Canadian Medical Association Journal, vol. 174, no. 13, pp. 1861–1869, 2006.
[42] P. S. Blair, M. W. Platt, I. J. Smith, and P. J. Fleming, “Suddeninfant death syndrome and sleeping position in pre-term andlow birth weight infants: an opportunity for targeted interven-tion,”Archives of Disease in Childhood, vol. 91, no. 2, pp. 101–106,2006.
[43] R. Y. Moon and L. Fu, “Sudden infant death syndrome: anupdate,” Pediatrics in Review, vol. 33, pp. 314–320, 2012.
Submit your manuscripts athttp://www.hindawi.com
Stem CellsInternational
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
MEDIATORSINFLAMMATION
of
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Behavioural Neurology
EndocrinologyInternational Journal of
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Disease Markers
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
BioMed Research International
OncologyJournal of
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Oxidative Medicine and Cellular Longevity
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
PPAR Research
The Scientific World JournalHindawi Publishing Corporation http://www.hindawi.com Volume 2014
Immunology ResearchHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Journal of
ObesityJournal of
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Computational and Mathematical Methods in Medicine
OphthalmologyJournal of
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Diabetes ResearchJournal of
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Research and TreatmentAIDS
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Gastroenterology Research and Practice
Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014
Parkinson’s Disease
Evidence-Based Complementary and Alternative Medicine
Volume 2014Hindawi Publishing Corporationhttp://www.hindawi.com