The “smellscape” of mother's breast: Effects of odor masking and selective unmasking on neonatal arousal, oral, and visual responses

Abstract

Lactating women emit odor cues that release activity in newborns. Such cues may be carried in various substrates, including milk or areolar secretions. The present study aimed to examine the responses of infants facing their mother's breast and to sort out the source(s) of active volatile compounds emitted by the lactating breast. Infants (aged 3-4 days) were presented their mother's breast in two consecutive trials of 90 s each: a scentless condition (breast entirely covered with a transparent film) paired with one of four odorous conditions (fully exposed breast: n ¼ 15; nipple only exposed: 15; areola only exposed: 13; and milk exposed: 12). The infants were more orally activated when facing any of the odorous breast conditions than when facing the scentless breast. They cried earlier and longer, and opened their eyes less, when facing the scentless breast. Nipple, Areola, and Milk odors appeared to be equivalent to the whole breast odor in stimulating oral activity and in delaying crying onset. This study shows that volatile compounds originating in areolar secretions or milk release mouthing, stimulate eye opening, and delay and reduce crying in newborns.

The Secretion of Areolar (Montgomery's) Glands from Lactating Women Elicits Selective, Unconditional Responses in Neonates

“…Their reaction to AG odor was evident in a clear increase in duration of head and mouthing actions that, in line with prior work on human neonates [4], [17]–[20], are interpretable as reflecting interest and appetence.…”

The Secretion of Areolar (Montgomery's) Glands from Lactating Women Elicits Selective, Unconditional Responses in Neonates

“…Their reaction to AG odor was evident in a clear increase in duration of head and mouthing actions that, in line with prior work on human neonates [4], [17]–[20], are interpretable as reflecting interest and appetence.…”

A Randomized Controlled Trial: The Effect of Own Mother's Breast Milk Odor and Another Mother's Breast Milk Odor on Pain Level of Newborn Infants

“…We can conclude that the N-PASS score of newborns exposed to the smell of another mother's breast milk smell in our study was lower than that of the control group because the newborns responded positively to familiar smells. 18,[26][27][28][29][30] In our study, it was found that there was a significant difference ( p < 0.05) between the ''own mother's milk'' and the control group and between the ''another mother's milk'' group and the control group in terms of the heart rate (beats/ min) and oxygen saturation. It was determined that the control group was the group with the highest average heart rate and lowest oxygen saturation.…”

“…Studies 16,18,25 have shown that the odor of breast milk has positive effects on the newborns. Doucet et al, 26 in their study of 55 healthy newborns born between the 38th and 42nd gestational week, noted that the smell of breast milk was Bold indicates significant at 0.01 £ p < 0.05; highly significant at 0.001 £ p < 0.01; very highly significant at p < 0.001.…”

“…Studies 16,18,25 have shown that the odor of breast milk has positive effects on the newborns. Doucet et al, 26 in their study of 55 healthy newborns born between the 38th and 42nd gestational week, noted that the smell of breast milk was associated with mouth opening, licking, stimulation of eyes, and decreased and delayed crying in newborns. In another study 27 using the smell of breast milk and formula milk during heel lance, the pain scores of newborns who smelled breast milk were significantly lower than the other group.…”

Olfactory-to-visual facilitation in the infant brain declines gradually from 4 to 12 months

“…The mother's body odor is a salient chemosensory stimulus that accompanies infants from the very beginning of life and promotes specific physiological, behavioral and neural responses already in neonates (Schaal et al., 2020 for review). By stimulating eye opening at birth (Doucet et al., 2007 ), maternal odor favors optimal exposure to the mother's face during nursing and caregiving. Later on, infants are often carried by their mother while engaged in social interactions, leading to co‐exposure to the mother's odor and to various (un)familiar faces.…”

The Secretion of Areolar (Montgomery's) Glands from Lactating Women Elicits Selective, Unconditional Responses in Neonates

“…Their reaction to AG odor was evident in a clear increase in duration of head and mouthing actions that, in line with prior work on human neonates [4], [17]–[20], are interpretable as reflecting interest and appetence.…”

A Randomized Controlled Trial: The Effect of Own Mother's Breast Milk Odor and Another Mother's Breast Milk Odor on Pain Level of Newborn Infants

“…We can conclude that the N-PASS score of newborns exposed to the smell of another mother's breast milk smell in our study was lower than that of the control group because the newborns responded positively to familiar smells. 18,[26][27][28][29][30] In our study, it was found that there was a significant difference ( p < 0.05) between the ''own mother's milk'' and the control group and between the ''another mother's milk'' group and the control group in terms of the heart rate (beats/ min) and oxygen saturation. It was determined that the control group was the group with the highest average heart rate and lowest oxygen saturation.…”

“…Studies 16,18,25 have shown that the odor of breast milk has positive effects on the newborns. Doucet et al, 26 in their study of 55 healthy newborns born between the 38th and 42nd gestational week, noted that the smell of breast milk was Bold indicates significant at 0.01 £ p < 0.05; highly significant at 0.001 £ p < 0.01; very highly significant at p < 0.001.…”

“…Studies 16,18,25 have shown that the odor of breast milk has positive effects on the newborns. Doucet et al, 26 in their study of 55 healthy newborns born between the 38th and 42nd gestational week, noted that the smell of breast milk was associated with mouth opening, licking, stimulation of eyes, and decreased and delayed crying in newborns. In another study 27 using the smell of breast milk and formula milk during heel lance, the pain scores of newborns who smelled breast milk were significantly lower than the other group.…”

Olfactory-to-visual facilitation in the infant brain declines gradually from 4 to 12 months

“…The mother's body odor is a salient chemosensory stimulus that accompanies infants from the very beginning of life and promotes specific physiological, behavioral and neural responses already in neonates (Schaal et al., 2020 for review). By stimulating eye opening at birth (Doucet et al., 2007 ), maternal odor favors optimal exposure to the mother's face during nursing and caregiving. Later on, infants are often carried by their mother while engaged in social interactions, leading to co‐exposure to the mother's odor and to various (un)familiar faces.…”

The Secretion of Areolar (Montgomery's) Glands from Lactating Women Elicits Selective, Unconditional Responses in Neonates

“…Their reaction to AG odor was evident in a clear increase in duration of head and mouthing actions that, in line with prior work on human neonates [4], [17]–[20], are interpretable as reflecting interest and appetence.…”

A Randomized Controlled Trial: The Effect of Own Mother's Breast Milk Odor and Another Mother's Breast Milk Odor on Pain Level of Newborn Infants

“…We can conclude that the N-PASS score of newborns exposed to the smell of another mother's breast milk smell in our study was lower than that of the control group because the newborns responded positively to familiar smells. 18,[26][27][28][29][30] In our study, it was found that there was a significant difference ( p < 0.05) between the ''own mother's milk'' and the control group and between the ''another mother's milk'' group and the control group in terms of the heart rate (beats/ min) and oxygen saturation. It was determined that the control group was the group with the highest average heart rate and lowest oxygen saturation.…”

“…Studies 16,18,25 have shown that the odor of breast milk has positive effects on the newborns. Doucet et al, 26 in their study of 55 healthy newborns born between the 38th and 42nd gestational week, noted that the smell of breast milk was Bold indicates significant at 0.01 £ p < 0.05; highly significant at 0.001 £ p < 0.01; very highly significant at p < 0.001.…”

“…Studies 16,18,25 have shown that the odor of breast milk has positive effects on the newborns. Doucet et al, 26 in their study of 55 healthy newborns born between the 38th and 42nd gestational week, noted that the smell of breast milk was associated with mouth opening, licking, stimulation of eyes, and decreased and delayed crying in newborns. In another study 27 using the smell of breast milk and formula milk during heel lance, the pain scores of newborns who smelled breast milk were significantly lower than the other group.…”

Olfactory-to-visual facilitation in the infant brain declines gradually from 4 to 12 months

“…The mother's body odor is a salient chemosensory stimulus that accompanies infants from the very beginning of life and promotes specific physiological, behavioral and neural responses already in neonates (Schaal et al., 2020 for review). By stimulating eye opening at birth (Doucet et al., 2007 ), maternal odor favors optimal exposure to the mother's face during nursing and caregiving. Later on, infants are often carried by their mother while engaged in social interactions, leading to co‐exposure to the mother's odor and to various (un)familiar faces.…”