ArticlePDF Available

Does the newborn baby find the nipple by smell?

Authors:

Abstract

We studied the involvement of naturally occurring odours in guiding the baby to the nipple. One breast of each participating mother was washed immediately after delivery. The newborn infant was placed prone between the breasts. Of 30 infants, 22 spontaneously selected the unwashed breast. The washing procedure had no effect on breast temperature. We concluded that the infants responded to olfactory differences between the washed and unwashed breasts.
THE IINCET
;R
E
.z
.9
16
T4
10
a
6
4
O>10 weeks @>12
weeks a>18
weeks
Mean
+ 1.O SD
..........4
.........T9:l:.119.,s.q..............o...'
__-€-------{
Mean + 1.8 SD and mean 2.O
+ SD
diagnosis are limited. If facilities are available, especially
during the first trimester, fetal DNA analysis of cr genes
still remains the method of choice.
Retsroncsg
I lai-Inio LE . Atpha-chlin thslassaemia bd hyatrops fetalis in Malaya:
repon offive cases.
alood t962120:581 91.
2 Todd D, lli MCS, BEsa CA. Thalassaemi. dd hy&ops fet iF
family studies. a {t 1967; 3: 347-52.
3 Thum.srlhir B, Nsd.sui. A, Silpisorukasol S. Hydrops fetalis
associ.ted with Ban\ haemoglobir in Nonh€m Thziland. J Pediorr
t9a6t73, \32 34.
4 !fi/€athe.sll
DJ,
Cless
JB,
vons HB. The haemoslobin
constitution of
infants $'ith ha€moglobin Ban's hydrops fetalis s}aldrome. BrJ
Ha atol197Otlat 357-67 -
5 Li.ns ST, Vons V, So
"0K Ma HK, ChD V, Todd D. Homozysous
o-thalassaemia: €linical
presentation,
diagnosis and management. A
review of46 cases. B/tObset Gtnae.ol l985j92t 6a0-a4.
6 Chan V, Ghosh A, Chan TK, Vong V, Todd D. Prenalal diaenosis of
homozygous
d-thalassaenia by direct DNA Dalysis of ucultured
amniotic fluid €€lls. B/VJ 1984;244. t327 39.
7 Rubin EM, Kan YW. A simple sensirive
prenaral test for hydrops fetalis
c.used by o-thllassaemia - Lafl.et l9a5t i: 7 5-77 .
8 Hsieh FJ, Chang FM, Ko TM, Kuo Pr. Chans
DY, CbeD
HY. The
antenatal blood
gas
and acid-base status ofnormal fetuses and
hydiopic feruses wirh Bart's hemoglobiDop{hy. Obrkt q)iecol rS89i
74t722 2t.
9 Kanokponssakdi S, Fucharoetr S, Varanasiri C, Thonslairosm P,
Vinichasoon
P, ManassakomJ.
UlEasonosrrphic merhods for
detection
ofhaemoglobin Ban's hydrops feralis in $e second rimesrer
ofpregnancy. ,t'at Drap, 1990; 10:809 13.
lo Ghosh
A, Tang MHY, Liang ST, Ma HK Chan V, Chan TK.
Uhrasound evaluation of pregnancies
at risk for homozygous d-
thalassaemia- 1 . Irtaar D,iTr l9A7:7t 3O7 11.
Proportion
positive
among cases
(%)
Figure: Percentago of posltives
among cases
(pregnancles
affocted by homozygous cr-thalassaeml+1) and controls
(nolmal
and o-thalassaemia-1
pregnancles)
at dlfferent
gostatlons
at varlous cutdts of placental
thlckness
12 weeks', a cut-off lower tlun mean plus 2 SD only
decreased specificiry wiLhour any increase
in sensitiviry.
Measurement of placental thickness du ng first and
second trimeste$ can differentiate normal ftom an
affected pregnancy in women at risk of giving birth to an
infant with homozygous cr-thalassaemia- l. A cut-off of
mean placental thickness plus 2 SD is appropriate. The
sensitivfty of placental drickness measulement in
derecting an affected pregnancy before 12 weeks'
gestation is low. In 2 pregnancies with a false-negative
result after 12 weeks' tie placentas were large on
ulrrasound, bur dickness was normal. With experience,
one should be able to recognise this tlpe ofplacenta. Both
these placentas were thought to be abnormal at the time
of amniocentesis. Measurement of placental volume
insread of thickness might be moie useful in dris situation.
However, in real-time sector scan, the whole length ofthe
placenta cannot be imaged during second trimester, and
volume measurement may be inaccurate.
Fetuses affected by homozygous c-thalassaemia-l
develop severe anaemia in early fetal life. This leads to
hydropic changes including an increase in placental
thickness and cardiomegaly. Increases in placental
thickness precede cardiomegaly.lo The increase in
placental rhickness occurred as early as the 10th
gestational week. !(/ith mean plus 2 SD, we could identifu
most affected pregnancies after 12 weeks and by 18
weeks' gestation, all affected pregnancies were detected.
Hence a normal placental thickness at or after the l8th
gestational week is reassuring and may obviate the need
for further invasive procedures to confrm normality.
An abnormal placental thickness is highly suggesrive
but not absolutely diagncistic of an affected pregnancy
and for earlier gestationr some of the abnormal
pregnancies could not be detected, Therefore invasive
diagnostic evaluation is necessary- Since the main
objective of prenatal diagnosis of homozygous o-
thalassaernia-l is reduction of maternal morbidity rather
tian prevention of birth of afected infants, serial
measurement of placental thickness may be an altemative
cost-effective method for exclusion of the disolder,
particularly in areas where resources for prenatal
Dop.rtment ot Otstetrlcs and Gynaecology.
Unlvsl3lty ot Hong Nong,
Tsan Yuk Hospltal, Hospltal Road,
Hong Kong
(A Ghosh
FRcoc, I\, H Y Tang MRcoG, Y H Lam MRcoG,
E Fung MRcoc); and Departnent of Mediclne,
Queen
Mary HGpltal,
Pokfulam, Hong Kong
(V Chan PhD)
Cor€Dond6nce to: Dr A Ghosh
Does the newboln baby find the nipple by
smell?
H Varendi, R H Poftet, J Winbery
We studied the
involvement of naturally occurring odours in
guiding
the baby to the nipple. One breast of each
participating
mother was washed immediately after
delivery. The newborn
infant was
placed prone
between the
breasts. Of 30 infants, 22 spontaneously selected the
unwashed breast. The washing
procedure
had no effect on
breast temperature.
We concluded that the infants
responded to olfactory differences
between the washed and
unwashed breast6.
Lancet
1994; 344: 989-90
Healdry newbom infants placed
between their mother's
breasts
locate the nipple without assistance
and typically
begin to suck within the first hour after bi-rrh.r Newbom
rats, for exampler fail to locate the oipple if their sense
of
smell is experimentally disrupred'? or if the modrels
ventrum is thoroughly washed.! Breastfed human infants
responded
differentially to a gauze pad that had been
wom over dleir mother's nipple compared with an
odorised pad ftorn an unfamiliar woman, indicating that
vol 144
' Ocrcber 8, 1994 989
THE IINCET
they recognise their mother's scent.d' Bteast odours from
lactating women are generally attractive to infantsr
regardless of their mode of feeding..t At 2 weeks of age,
babies drat had been boftle-fed since birdr spent more
time tumed toward the breast pad ftom an unfamiliat
nursing mother than in the direction of a pad treated widt
their familiar formula.s Could chemical cues associared
with the areola and nipple be implicated in initial
(unassisted) nipple localisation and sucking?' To assess
this hypothesis, nipple searching was observed after one of
the mother's breasts
had been thoroughly washed> drereby
pardy eliminating narural odou!.
36 full-term babies
bom of mothers wilhout analgesia and who
had no postpartum complications wete aecruited. 6 were
subsequently excluded
because of disrurbed
nasal breathing
(4)
or failure to respond to the mothe!'s breast during a test session
(2). The final sample was 14 girls and 16 boys (gestarionel
age
37-41 weeksj mean
binhweight 3676 ISD 4231
g; Apgar scores
>7 at I and 5 min).
Irnmediately
after birth, the baby was dried, laid skin-to-skin
on rhe mother's abdomen altd covered with a blanket. An
assistent washed
one of the mother's breasts for about 15 cm
around
the nipple with an odou.less liquid soap: Mild$el for t5
mothels and hctacyd (Sanofi,
pH 3.5) for the remailring
15.
The washed breast was rinsed with lukewarm weter and dried.
The right breest was
washed in 15 cases
and the left breast in the
others. Modrers were randomly assigned to the two sogps and to
the right/left sides.
After the washed breast was dried, the obsetver (unaware of
which breast had been cleaned) entered the room and moved the
baby from the mother's abdomen to the "starr" posirion-ie,
nose in the midline of the mother's chest, eyes at the level of the
nipples.
Observation and recording
of the baby's behaviour
then
began
(5-13 min after birrh; mean 9.9) and continued until the
infant found
the nipple and began ro suck vigorously.
Before delivery, the mother was rold that she and the observer
would watch whether the infant could find the nipple withour
help. Mothers were instrucred not to tell the observer which
breast had
been
washed.
Informed consent was
obtained fiom all
mothers, and fathers when present, and the study was approved
by the locel ethics
committee.
To sludy any effecr of the washing on breast temperaruie, en
additionel 6 rnothers underwent
lbe same washing within 12
hours after delivery. Surface temperatures were recorded et the
nipple, border betwi:en the areola and white breast-skin, and
midway between rhe areola
and centre of the ches! at 5-10,
l5-20, 30-35, and 50-55 min.
25 infants spontaneously grasped a nipple and sucked
(median latency 5l min after birth [range 22-100]). The
odrer 5 requiled assistance in grasping the prolapsed
nipple; the baby had moudr contacr wirh one of rhe
nipples and repeatedly attempted to grasp it before the
observer assisted by placing rhe nipple in the infant's
mouth (median latency 54 min after birth [22-85]). None
of these 5 infants aftempted to gasp the altemative
nipple. 22 (12 boys, l0 girls) ofthe 30 infants selected the '
unwashed breast, The unwashed breast was selected by
l0 infants in the Mild$el and 12 in the Lactacyd soap
groups. The table shows median times for other early
behaviours.
The median temperature of washed breasts was slighdy
above that of unwashed breasts (maximum median
difference was 0'5"C).
Vithin l-2 h after birth, babies preferred their modrer's
unwashed bteast, which is consistent with studies of non-
human mammals showing dlat washing the mother's
nipplevventrum resulted in disturbed nipple finding and
feeding. \fe excluded the possibility thar our infants had
responded to differences in the warmth of dre two breasts.
M€daan
{
range)
time
{
min) alter birth.
Table: Early
postnatal
behavlour In
30 nowborn
Intante
rJge
explain the preference
for the unwashed breast in that
the infants were responding to differences in snell.
Besides
secreting milk and colostrum,
rhe nipple/areola is
dense in glands that might secrere attractive odours. The
washing
would have reduced o! eliminated such cues,
which is consistent
with infants orienring prefelentially
towards a gauze
pad contaminared with the breast odour
of a lactating woman compared with an odourless control
pad.+"
Naturally occurring matemal odoun may have a
role in guiding dre neonate ro rhe nipple, and thereby
contribute to early nipple attachment and sucking. The
causes of early failures of breasdeeding are often
unknown.' Since breasdeeding is sensitive
ro even minor
disturbances of the spontaneous interactions between
mother and baby,'o biological facton should be given
attention, Ijnnecessary routine cleaning may interfere
with the establishmenr
ofsuccessful early
breasdeedhg by
elimination of iie infant's access
ro biologically relevant
chemical signals.
This study was aided by grsnts ftom rhe Foundarion "Frimurare
BamhuseC' and fiom the Karclirst€ lnslirure.
Unwasned Washed
breasl
(n=22) breasl
{n-8)
Firsl handlomouth
movement
No oi head tornings belore
choice ot side
First moutt}areola
contact
Fnsi successiulnippl€
contacl
(in
mouth)
N0 ol sucking attempts betore success
20 (1I41t 19 (10-30)
23 (10-60) 20 t7-291
1(0-6) 2 (G6)
50
(1+99) 44122-72)
51(22-100) 45
t22-73)
5
(1-2r) 411-71
54122-LOO\ 4a122-73\
Reiarencog
I Widsirttm AM, Ransjo-Arvisson AB, Chrisr€nsson K, er al. casric
suction in healthy n€wbom intun$. Acto Paediat l9a7 ; 75t 566-72.
2 Teicher MH, Flaum LE, ViUiams M, Eckhen SJ, Lumia AR. Swivll,
sowth and suckling behavior of neoniolly butbecromiz€d rats. P,lry'bi
Behao 1978i 2lt 553-61 .
3 Hofe. MA, Shair H, Sinsh P. Evidence thsr mitemal venrlal skir
substances
promote suckling in infa rirs. Pr),'rio/aehao 1976:17.
l3t-36.
4 Macfarlane A. Olfaction in lhe developm€nr ofsocial preferences
in the
humd neonate.
ln: Poner R, O'Connor M, €ds. Parenr-infanr
interaction
(Ciba
Foundation Slrnposium 33). N€w York Elsevier,
1975:103-13.
5 Schaal B, Monmgner H, Henlingq er al. Les stimulations oflactives
dans
les.elations
€ntre I'enfant et la mere. R?rrcd Nlf D@ 1980:
20:
443 54.
6 Makn I f, Poner RH. Att"activeness of lacraring females' breast odors
to neonltes.
CirrTdDe!, 1989;60: 803-10.
7 Po(er RH, Makin J$f, Davis LB, Christensen KM. BressFfed inflnls
respond to olfactory cues fiom deir o$n moth€r a.d unfamilia.
lactatins femafes. lrldz, A.hao D@ r992t lst a5-93.
8 Poner RH, Makin IV, Dlvis LB. Chrisrensen KM. An assessm€nt of
th€ salient olfadory enimnment of formula-fed infrn6. Pb)tiol Behal)
1991, 50: 907-l l.
9 Goldman AS, Garza C. Futur€ research in hrman milk. Ped;ot Res
1987
t 22t 493-96.
l0 Rishard I- Alad€ MO. Efrect of delivery mom routines on success
of
first breasFfeed. lar..r 1990;336:
I105-07.
Tartu Unlverslty Chlldton'6 Hospltal, Tartu, Eatonla
(H
Varendi MD);
Isbo6tollo de
Compo.toment Anlmal, URA ll91CI{RS,/INRA,
l{ouzllly, Franco
(R H Porter
pnD);
and
lnstltutlon
tor Womsn and
Chlld floalth, t(arollnska llo3pltal, Karolltuk ln3tltuto, Stockholh,
Sw€don
(Prof
J Winberg MD)
Corospondonco to: Dr Heili Varendi, Tanu University Children's
Hospital, 6 Lunini
Str,
EE 2400 Tartu.
Estonia
990 Vol 344
. Octobe! 8, 1994
... Observational studies of neonatal behavior as well as electroencephalography (EEG) studies show that odors are discriminated by newborns (Gellrich et al., 2021;Marlier and Schaal, 2005). The olfactory system plays a vital role in early development (Gellrich et al., 2021;Marlier and Schaal, 2005), it is important for orientation and postnatal bonding, as well as for feeding (Porter et al., 1992;Schaal, 2000;Varendi et al., 1994). ...
... This could lead to activation in different brain regions. Additionally, while milk odor may be perceived as faint by adults, it is probable that newborns perceive it differently and can use it to identify their mothers and locate their breasts (Porter et al., 1992;Varendi et al., 1994). ...
... First, olfaction is essential for ingestive behavior, aiding in the detection and identification of food (e.g., Schleich & Zenuto, 2007;Vander Wall et al., 2003), and it plays a key role in modulating food intake through the "appetizer effect" (Yeomans, 2000). Newborns use their sense of smell to locate their mother's nipple for suckling (Varendi et al., 1994). ...
Article
The Children's Personal Significance of Olfaction Questionnaire (ChiPSO) is a measurement tool for assessing the importance of olfactory information in children. Due to limited research on the importance of olfaction in Chinese children, this study aims to translate the ChiPSO into Chinese and validate this version, thereby examining its applicability within the Chinese context. The study involved 1015 participants aged 6–15 years, with confirmatory factor analysis (CFA) used to evaluate the questionnaire's factor structure, alongside tests for internal consistency, test–retest reliability, and concurrent validity. The results confirmed a robust three‐factor structure (food, environment, and social) with adequate internal consistency and test–retest reliability. Furthermore, concurrent validity was confirmed through significant correlations with the Chemosensory Pleasure Scale for Children and the Body Odor Sniffing Questionnaire. In conclusion, this study effectively validated the ChiPSO‐C, proving it to be a reliable instrument for investigating olfactory significance in Chinese children. Practical Application The Chinese version of the Children's Personal Significance of Olfaction offers a validated tool to assess the personal significance of olfaction in Chinese children. Researchers and educators can use this tool to better understand and support children who may rely more significantly on olfactory cues for learning and interaction. Furthermore, this tool facilitates cross‐cultural research by providing a means to compare olfactory significance across different cultural contexts.
... Moreover, studies indicate that olfactory receptors retain enduring postnatal memories of the volatile constituents found in amniotic fluid. This retention enables infants to discern the distinct odors emanating from their mother's breastmilk in contrast to those of other individuals [32]. Preterm infants, exposed to the scent of breast milk, demonstrated prolonged sucking sessions and increased feeding outbursts [31]. ...
Article
Full-text available
Aim To evaluate the effect of olfactory and/or gustatory stimulation interventions on feeding outcomes in preterm infants. Methods We conducted systematic searches across various academic databases, including PubMed, Embase, Web of Science, the Cochrane Library, the Chinese Biomedical Literature Service System, China National Knowledge Infrastructure, the Wanfang Database, and the Wipu Database. These searches aimed to identify randomized controlled trials investigating the impact of olfactory and/or gustatory stimulation on preterm infants. The search period spanned from the inception of the databases until December 2022. Two independent evaluators autonomously reviewed the literature, extracted pertinent data, assessed the quality of the included studies, and conducted a meta-analysis using RevMan 5.3 software. Results A total of 7 randomized controlled trials or quasi-experimental studies were included, with a total of 871 participants. Olfactory and gustatory stimulation demonstrated a reduction in the time to full enteral feeds in preterm infants when compared to usual care (MD = -1.60 days; 95% CI = -2.31, -0.89; p<0.0001). No substantial evidence was identified regarding the influence of olfactory and gustatory stimulation on the duration of gastric tube placement, length of hospitalization, incidence of necrotizing enterocolitis, or occurrence of spontaneous bowel perforation in preterm infants. Conclusions Olfactory and gustatory stimulation show potential benefits for preterm infants. However, due to the low to very low level of certainty associated with the available data, our ability to assess the effects is limited. Further trials and studies are essential to enhance our understanding of the mechanisms and effectiveness of olfactory and gustatory stimulation therapies.
... odors in such route descriptions ("Turn right at the smell of lavender"). However, the use of olfactory cues for spatial orientation is evident even in infants, who locate their mothers' nipples based on scent when visual cues are not yet available (Varendi et al., 1994). Moreover, research has shown that humans can utilize olfactory landmark information for navigation in laboratory settings (e.g., Hamburger & Knauff, 2019). ...
Article
Full-text available
An old misconception led to the belief that humans have a poor sense of smell. The sense of smell is a rather primitive but important sense that our ancestors used for hunting, mating, and survival. Throughout the past decades and even centuries, the importance of this sense for our daily lives has been lost under the assumption that “humans have a bad sense of smell.” Especially in combination with spatial orientation and navigation, the sense of smell is of particular importance in a lot of our close relatives in the animal kingdom. Research on humans reveals an immense gap here compared to research on nonhuman animals. However, there are some findings that suggest that olfaction is also important in human navigation: Olfactory cues are more emotional-laden and memorable than visual cues and it is evolutionary only logical that humans, similar to their close relatives from the animal kingdom, use their sense of smell for orientation as well. Therefore, it is very likely that humans, similar to other animals, use their olfactory system for navigation. The main difference is that humans are not consciously aware of it. As we outline in this review, several findings may explain why olfactory navigation in humans is primarily an implicit process and why it has mainly been neglected in the past. We further give suggestions for future research and how findings in olfactory human navigation can be used for other field outside wayfinding, such as aromatherapy or Alzheimer’s diagnosis.
... They respond to a panel of natural scents emanating from their parturient or lactating mother (e.g., amniotic fluid: Schaal et al., 1995;Varendi et al., 1997;breast: Doucet et al., 2007;Macfarlane, 1975;Russel, 1976; breast and neck: Schaal et al., 1980;axillae: Cernoch & Porter, 1985;reviewed in Porter & Winberg, 1999;Schaal, 2015;Schaal et al., 2019Schaal et al., , 2020. Volatile compounds emitted from the mammae appear especially momentous in guiding infants to the nipple (Varendi et al., 1994(Varendi et al., , 1997, increasing their general creeping and directional rooting (Hym et al., 2021;Varendi & Porter, 2001), stimulating their oral activity Marlier et al, 1998;Soussignan et al., 1997), and promoting successful latching and sucking (Mizuno & Ueda, 2006;Schaal et al., 2006;Doucet et al., 2007). Breast odor can also stimulate arousal and visual attention (Doucet et al., 2007), favoring the infant's intake of information beyond olfaction (Durand et al., 2013Zimmerman & DeSousa, 2018), and the early fine-tuning of social cognition (Jessen, 2020;Leleu et al., 2020;Rekow & Leleu, 2023;Rekow et al., 2021). ...
Article
Human milk odor is attractive and appetitive for human newborns. Here, we studied behavioral and heart‐rate (HR) responses of 2‐day‐old neonates to the odor of human colostrum. To evaluate detection in two conditions of stimulus delivery, we first presented the odor of total colostrum against water. Second, the hedonic specificity of total colostrum odor was tested against vanilla odor. Third, we delivered only the fresh effluvium of colostrum separated from the colostrum matrix; the stability of this colostrum effluvium was then tested after deep congelation; finally, after sorptive extraction of fresh colostrum headspace, we assessed the activity of colostrum volatiles eluting from the gas chromatograph (GC). Regardless of the stimulus‐delivery method, neonates displayed attraction reactions (HR decrease) as well as appetitive oral responses to the odor of total colostrum but not to vanilla odor. The effluvium separated from the fresh colostrum matrix remained appetitive but appeared labile under deep freezing. Finally, volatiles from fresh colostrum effluvium remained behaviorally active after GC elution, although at lower magnitude. In sum, fresh colostrum effluvium and its eluate elicited a consistent increase in newborns’ oral activity (relative to water or vanilla), and they induced shallow HR decrease. Newborns’ appetitive oral behavior was the most reproducible response criterion to the effluvium of colostrum. In conclusion, a set of unidentified volatile compounds from human colostrum is robust enough after extraction from the original matrix and chromatographic processing to continue eliciting appetitive responses in neonates, thus opening new directions to isolate and assay specific volatile molecules of colostrum.
Article
Full-text available
A number of mammalian species discriminate their mates by their smell. Humans also produce temporarily stable odour signatures. The results of several studies showed that humans are able to recognise their own odour, the odour of their partner or relatives. Also the unfamiliar subjects can match the odour of children and their mothers, but not the odour of spouses. This suggests that as on visual level, the odour of individual relatives resembles each other, probably due to genetic factors. Odour communication is a powerful tool in very early infant´s life already. A newborn can find the nipple and recognise its mother within a few hours after birth. A mother is also able to identify the smell of her infant even when her contact with the baby was restricted to several hours. Studies on gender judgments by smell found that the more intense and unpleasant smells are mostly attributed to men and vice versa. Thus gender is presumably not perceived per se by smell, but rather by perceived intensity. The aim of this paper is to critically review studies on human odour recognition and to propose the directions of future research.
Article
In this study, the transfer of odorants, namely vanilla, and garlic, into the amniotic fluid (AF) during the second trimester was investigated by examination of collected AF samples through healthy adults. Eleven AF samples were collected from pregnant women (aged 32.9 ± 4.9 yr, 16–25 wk of gestation) undergoing diagnostic amniocentesis after eating garlic oil or vanilla powder in high-fat yogurt. The control group did not receive food before amniocentesis. Two vanilla, 3 garlic, and 6 control samples were collected through amniocentesis 60–120 min after ingestion. Samples were collected at −80 °C and carefully defrosted over 12 h at the same time point. Sixteen healthy volunteers (8 males, aged 26.5 ± 5.0 yr) were asked to judge AF samples with potential garlic or vanilla odors from controls in a 2-alternative forced choice (2AFC) paradigm. Judges were able to identify vanilla in the AF samples with an estimated probability of 50%, resulting in a significant P-value of < 0.001. In contrast, the identification of garlic was unsuccessful with a P-value of 0.86, and only 2 judges were able to identify both vanilla and garlic. According to the results of this study, the vanilla odor probably passes into the amniotic fluid.
Article
Two-week-old breast-feeding infants were tested for their responses to alfactory cues produced by nursing mothers. Mean durations of orientation in the direction of a breast pad worn by an unfamiliar lactating female were greater than towards either a clean control pad or an axillary pad from the same stimulus female. When tested with odor pads worn by their own mother, however, infants did not orient differentially to her breast versus axillary odors. Breast odors from nursing females appear to be generally attactive to neonates. Moreover, breast-fed infants are capable of recognizing their own mother through the scent of her breast or axillary secretions, and are attracted to both of these sources of her unique alfactory signature.
Article
Washing a lactating rat's ventral skin with acetone, alcohol and water markedly reduces the effectiveness with which her 2-week-old infants can initiate suckling on the anesthetized mother. Control experiments with detailed thermal and behavioral measures give evidence tending to rule out lowered skin temperature, altered thermal gradients, changed tactile characteristics of abdominal fur or nipples and aversion to remaining traces of the organic solvents as responsible for the infants' failure to find and attach to nipples. The data suggest that some substance(s) on the skin of the mother's ventrum act as olfactory and/or gustatory cues for the infants' orientation and attachment to nipples.
Article
The importance of the olfactory bulbs in the neonatal rats ability to suckle, and hence survive and grow, was evaluated using modified surgical and post-operative rearing conditions. More than 90% of two-day-old bilaterally bulbectomized pups survived surgery and recovered sufficiently to gain weight and grow at near-normal rates. However, these pups were markedly deficient in their ability to locate and attach to their anesthetized mothers' nipples. They did however, manage to attach when held in direct contact with these nipples. As expected, washing olfactory cues for suckling from the nipple surface with methylene chloride-ethanol severely disrupted the suckling behavior of their normal and unilaterally bulbectomized littermates. Removing these cues had no effect on the attachment behavior of bilaterally bulbectomized pups, demonstrating that neonatal rats possess sufficient behavioral plasticity to utilize other cues for suckling in the absence of olfaction.
Article
Olfactory preferences of two-week-old bottle-fed infants were assessed in a series of simultaneous two-choice tests. Infants of each sex displayed preferential orientation to a stimulus pad worn on their mother's breast over a clean control pad. When maternal breast odor was paired with the odor of the infants' formula, however, boys spent more time oriented toward the formula odor, whereas girls evinced no reliable preferences. Although the subject infants had no prior direct contact with odors emanating from the breasts of lactating females, but had recurring reinforced exposure to the odor of their familiar formula (in the context of feeding), the former scents elicited a more positive response. Preferential orientation to lactating-breast odors reflects adaptive inborn attraction to cues associated with the natural food source for human neonates.
Article
72 infants delivered normally were observed for 2 h after birth. In the separation group (n = 34), the infant was placed on the mother's abdomen immediately after birth but removed after about 20 min for measuring and dressing. In the contact group (n = 38) contact between mother and infant was uninterrupted for at least 1 h. After about 20 min the infants began to make crawling movements towards the breast; the rooting reflex soon came into play, and at an average of 50 min after birth most of the infants were sucking at the breast. More infants in the contact group than in the separation group showed the correct sucking technique (24/38 vs 7/34). 40 (56%) of the 72 mothers had received pethidine during labour; the infants were also sedated and most of them (25/40) did not suck at all. It is suggested that contact between mother and infant should be uninterrupted during the first hour after birth or until the first breast-feed has been accomplished, and that use of drugs such as pethidine should be restricted.
Article
A series of experiments investigated the responses of human infants to olfactory cues produced by lactating females. 2-week-old bottle-feeding girls oriented preferentially to the breast odor (odorized pad) of a nursing woman when paired with such odors from either a nonparturient female or axillary odors from the same lactating female. Responses to axillary odor from a lactating female did not differ from those to a clean (nonodorized) pad. These data indicate that breast odors from lactating females are especially attractive to female infants who are unfamiliar with the stimulus woman and who have had no prior breast-feeding experience.
Article
Because of the importance of breast-feeding to child health, research in the formation, composition, and biological effects of human milk should be strongly encouraged. Future exploration should include the processes that are responsible for the synthesis and secretion of human milk; the nature and function of the physical compartments in human milk; the structure and function of certain proteins and other components in human milk; and the in vivo fate and effect of a host of constituents including nutrients, growth factors, hormones, inducers, immunological factors, and antiinflammatory agents. Because of the potential public health benefits, these studies should be a high priority in pediatric research for the next decade.
Article
Gastric emptying of newborn infants is a procedure performed to prevent aspiration of gastric contents. The present investigation was conducted to study the effects of gastric suction on circulatory and behavioural parameters in 21 healthy newborn children (11 cases, 10 controls). A small elevation in mean arterial blood pressure was observed during gastric suction. The incidence of retching was also increased. In all children spontaneous sucking and rooting movements, as well as state of sleep and wakefulness were recorded. In the control group spontaneous sucking and rooting movements started occur 15 min after birth and reached a maximum at 45 and 60 min, respectively. The first hand to mouth movement was observed after a mean of 34 min and the infants found the nipple and started to suckle at about 55 min. This sequence of prefeeding behaviour was disrupted in children who had undergone gastric suction. The physiological side-effects induced by gastric suction are minor, but it seemed to be unpleasant for the child and no clear advantages are gained by the procedure.