Natural odour preferences of newborn infants change over time

Testing detectability, attractivity, hedonic specificity, extractability, and robustness of colostrum odor-Toward an olfactory bioassay for human neonates

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.

Skin-to-skin SDF positioning: The key to intersubjective intimacy between mother and very preterm newborn-A pilot matched-pair case-control study

Background

Skin-to-skin contact (SSC) has been widely studied in NICU and several meta-analyses have looked at its benefits, for both the baby and the parent. However, very few studies have investigated SSC' benefits for communication, in particular in the very-preterm newborn immediately after birth.

Aims

To investigate the immediate benefits of Supported Diagonal Flexion (SDF) positioning during SSC on the quality of mother-very-preterm newborn communication and to examine the coordination of the timing of communicative behaviors, just a few days after birth.

Subjects and study design

Monocentric prospective matched-pair case-control study. Thirty-four mothers and their very preterm infants (27 to 31 + 6 weeks GA, mean age at birth: 30 weeks GA) were assigned to one of the two SSC positioning, either the Vertical Control positioning (n = 17) or the SDF Intervention positioning (n = 17). Mother and newborn were filmed during the first 5 min of their first SSC.

Outcome measures

Infants' states of consciousness according to the Assessment of Preterm Infants' Behavior scale (APIB). Onset and duration of newborns' and mothers' vocalizations and their temporal proximity within a 1-s time-window.

Results

In comparison with the Vertical group, very preterm newborns in the SDF Intervention Group spent less time in a drowsy state and more in deep sleep. At 3.5 days of life, newborns' vocal production in SSC did not differ significantly between the two groups. Mothers offered a denser vocal envelope in the SDF group than in the Vertical group and their vocalizations were on average significantly longer. Moreover, in a one-second time-frame, temporal proximity of mother-very preterm newborn behaviors was greater in the SDF Intervention Group.

Conclusion

Although conducted on a limited number of dyads, our study shows that SDF positioning fosters mother-very preterm newborn intimate encounter during the very first skin to skin contact after delivery. Our pioneer data sheds light on the way a mother and her very preterm vocally meet, and constitutes a pilot step in the exploration of innate intersubjectivity in the context of very preterm birth.

Epidural Analgesia With or Without Oxytocin, but Not Oxytocin Alone, Administered During Birth Disturbs Infant Pre-feeding and Sucking Behaviors and Maternal Oxytocin Levels in Connection With a Breastfeed Two Days Later

Aims This work aimed to study consequences of medical interventions in connection with birth on infant pre-feeding and feeding behaviors and on maternal oxytocin levels in connection with a breastfeed 2 days later.

Materials and Methods Mothers and their full-term newborns (n = 41) were videotaped during a breastfeed 2 days after birth. Duration and quality of rooting [Infant Breastfeeding Assessment Tool (IBFAT)] were assessed. Maternal blood samples were collected, oxytocin levels were analyzed, and mean oxytocin level and variance were calculated. Data on medical interventions during birth, number of breastfeedings, and infant weight loss since birth were recorded. Data were analyzed using logistic regression models.

Results The duration of infant rooting was significantly shorter when the mother had received epidural analgesia. The shorter the duration of infant rooting, the more often infants had breastfed and the greater was the infant weight loss since birth. Mothers with epidural analgesia with oxytocin had the lowest oxytocin mean levels in connection with a breastfeed. Oxytocin variance correlated positively with quality of rooting and correlated negatively with infant weight loss. In the control group alone, we found similar patterns of associations with oxytocin levels.

Conclusion Epidural analgesia and epidural analgesia with oxytocin infusion in connection with birth negatively influenced infant rooting behavior and maternal mean oxytocin levels, respectively. Oxytocin infusion alone was without effect. The data also suggest that infants who suck well stimulate oxytocin release more efficiently, as expressed by a high oxytocin variance, leading to a better stimulation of milk production and consequently to a reduced infant weight loss 2 days after birth.

Neonatal cortical perceptions of maternal breast odours: A fNIRS study

AIM

The aim was to determine whether preterm and full-term newborn infants could process maternal breast odour at a cortical level.

METHODS

Newborn infants were exposed to cloths containing their own mother's breast odour and freshly laundered control cloths for 10 seconds, while functional near-infrared spectroscopy measured cortical activation in their olfactory processing areas. We studied 45 newborn infants born at 28-41 weeks of gestation and divided them into three groups: full-term (37-41 weeks), late preterm (33-36 weeks) and very preterm (28-32 weeks). Cortical activation was defined as a regional increase of oxyhaemoglobin following maternal breast odour stimuli.

RESULTS

Full-term infants demonstrated bilateral activation of their olfactory cortices following exposure to maternal breast odour. Late preterm infants and very preterm boys exhibited unilateral cortical activation, unlike very preterm girls.

CONCLUSION

Infants born from 32 weeks, and possibly earlier, could process low concentration maternal odours at a cortical level, which suggests they were more aware of their environment. These findings could make a significant contribution to improving the sensory environment of preterm infants and improve bonding.

Effects of smelling amniotic fluid on preterm infant's pain and stress during peripheral cannulation: A randomized controlled trial

AIM

To investigate the effect of smelling amniotic fluid on preterm infants' pain and stress caused by peripheral cannulation.

METHODS

This was a randomized controlled trial. The study sample consisted of 80 preterm infants meeting the case selection criteria and infants were randomly assigned to each group. However, in addition to the infants excluded from the study, total number of the infants in all the groups was 61. Infants in the amniotic fluid group smelled amniotic fluid for 15 min before, during, and after the application of peripheral cannulation while those in the control group received routine care during the procedure. The Premature Infant Pain Profile was used to assess their pain levels, and salivary cortisol analysis was performed to evaluate stress levels.

RESULTS

Preterm infants in the amniotic fluid and control groups had similar baseline characteristics. However, the pain levels of infants in the amniotic fluid group were significantly lower than of those in the control group during and after the procedure. After the procedure, cortisol levels of the infants in the amniotic fluid group were lower than of those in the control group, although this difference was not significant.

CONCLUSION

The intervention of smelling amniotic fluid is a practice that can be used for reducing pain and stress of preterm infants during peripheral cannulation.

The effect of smell and taste of milk during tube feeding of preterm infants (the Taste trial): a protocol for a randomised controlled trial

INTRODUCTION

Smell and taste of milk are not generally considered when tube feeding preterm infants. Preterm infants have rapid growth, particularly of the brain, and high caloric needs. Enteral feeding is often poorly tolerated which may lead to growth failure and long-term neurodevelopmental impairment. Smell and taste are strong stimulators of digestion and metabolism. We hypothesise that regular smell and taste during tube feeding will improve weight z-scores of very preterm infants at discharge from hospital.

METHODS AND ANALYSIS

Taste is a randomised, unblinded two-centre trial. Infants born at <29 weeks' gestation and/or <1250 g at birth and admitted to a participating neonatal intensive care unit are eligible. Randomisation occurs before infants receive two hourly feeds for 24 hours. Infants are randomised to either smell and taste of milk with each tube feed or tube feeding without the provision of smell and taste. The primary outcome is weight z-score at discharge. Secondary outcomes include: days to full enteral feeds, duration of parenteral nutrition, rate of late-onset sepsis, post menstrual age at removal of nasogastric tube and at discharge from hospital, anthropometric data and neurodevelopmental outcomes at 2 years of corrected age.

ETHICS AND DISSEMINATION

Human Research Ethics Committees of Mater Misericordiae (trial reference number: HREC/16/MHS/112) and the Royal Women's Hospital (trial reference number: 17/21) last approved the trial protocol (version 4.2; Date: 18 December 2018) and recruitment commenced in May 2017 and November 2017, respectively. The trial results will be published in a peer-reviewed journal and will be presented at national and international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12617000583347.

The Analgesic Effects of Maternal Milk Odor on Newborns: A Meta-Analysis

OBJECTIVE

The objective of this study was to evaluate the analgesic effects of maternal milk odor on newborns.

MATERIALS AND METHODS

We searched the literature in PubMed, MEDLINE, CINAHL, EMBASE, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) and collected all the randomized controlled trials (RCTs) investigating the effects of maternal milk odor versus scentless or other odors on procedural pain in newborns. The quality of included studies was assessed by the Cochrane Collaboration Risk of Bias tool. A meta-analysis was undertaken with the Review Manager 5.3 software and Stata version 11.0. Subgroup comparisons were prespecified according to the types of control groups.

RESULTS

Eight RCTs included a total of 453 participants. The results of meta-analysis showed that compared with the scentless group, the maternal milk odor group had lower pain scores during blood sampling (standardized mean difference, -0.81; 95% confidence interval [95% CI], -1.18 to -0.44; p < 0.001) and shorter crying time afterward (mean difference, -8.10; 95% CI, -15.46 to 0.73; p = 0.03). The maternal milk odor group had lower heart rate variability and oxygen saturation variability during and after a procedure, compared with both the scentless group and the vanilla group. However, no significant difference was identified in the mean heart rate and mean oxygen saturation in terms of the maternal milk odor group compared with amniotic fluid odor or mother's scent. The maternal milk odor group versus the formula milk odor group had shorter crying duration and lower levels of salivary cortisol after sampling.

CONCLUSIONS

Maternal milk odor appears to play an analgesic role in newborns. However, more high-quality studies are needed to confirm and quantitate the effect.

Care Through the Newborn's Eyes

Separation of mothers and infants after birth is standard practice for many hospitals, yet not evidence-based. Nonseparation clearly has numerous benefits. However, newborns lack a voice to make choices to direct their course of care. The evidence supports nonseparation strategies for mothers and infants that promote attachment, physiologic regulation, nutrition, sleep, communication, and management of stress/pain. Moreover, the evidence is compelling that nonseparation is essential. The time has come to act on the evidence and begin seeing the care we provide through the newborn's eyes.

Effects of Having Preterm Infants Smell Amniotic Fluid, Mother's Milk, and Mother's Odor During Heel Stick Procedure on Pain, Physiological Parameters, and Crying Duration

OBJECTIVE

The study aims to assess effects of having preterm infants smell amniotic fluid, mother's milk, and mother's odor during heel stick procedure on pain, physiological parameters, and crying duration.

MATERIALS AND METHODS

The study was a randomized controlled experimental research. The population of the study was made up of preterm infants receiving treatment and care at a neonatal intensive care unit, where the study was conducted between January 2015 and March 2016. The study was performed with 85 preterm infants who met the selection criteria. Infants were randomized into four groups: amniotic fluid, mother's milk, mother's odor, and control group. Data obtained were analyzed by percentage distributions, means, standard deviation, chi-square test, Kruskal-Wallis, and Dunnett's test.

RESULTS

While no significant difference was found between the groups in terms of total preterm infant pain profile score before, during, and after the heel stick procedure (p > 0.05), a significant difference was found in terms of SO₂ values (p < 0.05) and the difference was caused by the amniotic fluid group. Although no significant difference was found between the groups in terms of crying duration (p > 0.05), the amniotic fluid group had the lowest score, followed by the mother's milk group, the mother's odor group, and the control group.

CONCLUSIONS

Amniotic fluid, mother's milk, and mother's odor were not effective in preterm infants during painful procedures.

Early skin-to-skin contact for mothers and their healthy newborn infants

BACKGROUND

Mother-infant separation post birth is common. In standard hospital care, newborn infants are held wrapped or dressed in their mother's arms, placed in open cribs or under radiant warmers. Skin-to-skin contact (SSC) begins ideally at birth and should last continually until the end of the first breastfeeding. SSC involves placing the dried, naked baby prone on the mother's bare chest, often covered with a warm blanket. According to mammalian neuroscience, the intimate contact inherent in this place (habitat) evokes neuro-behaviors ensuring fulfillment of basic biological needs. This time frame immediately post birth may represent a 'sensitive period' for programming future physiology and behavior.

OBJECTIVES

To assess the effects of immediate or early SSC for healthy newborn infants compared to standard contact on establishment and maintenance of breastfeeding and infant physiology.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (17 December 2015), made personal contact with trialists, consulted the bibliography on kangaroo mother care (KMC) maintained by Dr Susan Ludington, and reviewed reference lists of retrieved studies.

SELECTION CRITERIA

Randomized controlled trials that compared immediate or early SSC with usual hospital care.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. Quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included 46 trials with 3850 women and their infants; 38 trials with 3472 women and infants contributed data to our analyses. Trials took place in 21 countries, and most recruited small samples (just 12 trials randomized more than 100 women). Eight trials included women who had SSC after cesarean birth. All infants recruited to trials were healthy, and the majority were full term. Six trials studied late preterm infants (greater than 35 weeks' gestation). No included trial met all criteria for good quality with respect to methodology and reporting; no trial was successfully blinded, and all analyses were imprecise due to small sample size. Many analyses had statistical heterogeneity due to considerable differences between SSC and standard care control groups. Results for womenSSC women were more likely than women with standard contact to be breastfeeding at one to four months post birth, though there was some uncertainty in this estimate due to risks of bias in included trials (average risk ratio (RR) 1.24, 95% confidence interval (CI) 1.07 to 1.43; participants = 887; studies = 14; I² = 41%; GRADE: moderate quality). SSC women also breast fed their infants longer, though data were limited (mean difference (MD) 64 days, 95% CI 37.96 to 89.50; participants = 264; studies = six; GRADE:low quality); this result was from a sensitivity analysis excluding one trial contributing all of the heterogeneity in the primary analysis. SSC women were probably more likely to exclusively breast feed from hospital discharge to one month post birth and from six weeks to six months post birth, though both analyses had substantial heterogeneity (from discharge average RR 1.30, 95% CI 1.12 to 1.49; participants = 711; studies = six; I² = 44%; GRADE: moderate quality; from six weeks average RR 1.50, 95% CI 1.18 to 1.90; participants = 640; studies = seven; I² = 62%; GRADE: moderate quality).Women in the SCC group had higher mean scores for breastfeeding effectiveness, with moderate heterogeneity (IBFAT (Infant Breastfeeding Assessment Tool) score MD 2.28, 95% CI 1.41 to 3.15; participants = 384; studies = four; I² = 41%). SSC infants were more likely to breast feed successfully during their first feed, with high heterogeneity (average RR 1.32, 95% CI 1.04 to 1.67; participants = 575; studies = five; I² = 85%). Results for infantsSSC infants had higher SCRIP (stability of the cardio-respiratory system) scores overall, suggesting better stabilization on three physiological parameters. However, there were few infants, and the clinical significance of the test was unclear because trialists reported averages of multiple time points (standardized mean difference (SMD) 1.24, 95% CI 0.76 to 1.72; participants = 81; studies = two; GRADE low quality). SSC infants had higher blood glucose levels (MD 10.49, 95% CI 8.39 to 12.59; participants = 144; studies = three; GRADE: low quality), but similar temperature to infants in standard care (MD 0.30 degree Celcius (°C) 95% CI 0.13 °C to 0.47 °C; participants = 558; studies = six; I² = 88%; GRADE: low quality). Women and infants after cesarean birthWomen practicing SSC after cesarean birth were probably more likely to breast feed one to four months post birth and to breast feed successfully (IBFAT score), but analyses were based on just two trials and few women. Evidence was insufficient to determine whether SSC could improve breastfeeding at other times after cesarean. Single trials contributed to infant respiratory rate, maternal pain and maternal state anxiety with no power to detect group differences. SubgroupsWe found no differences for any outcome when we compared times of initiation (immediate less than 10 minutes post birth versus early 10 minutes or more post birth) or lengths of contact time (60 minutes or less contact versus more than 60 minutes contact).

AUTHORS' CONCLUSIONS

Evidence supports the use of SSC to promote breastfeeding. Studies with larger sample sizes are necessary to confirm physiological benefit for infants during transition to extra-uterine life and to establish possible dose-response effects and optimal initiation time. Methodological quality of trials remains problematic, and small trials reporting different outcomes with different scales and limited data limit our confidence in the benefits of SSC for infants. Our review included only healthy infants, which limits the range of physiological parameters observed and makes their interpretation difficult.

The Effect of Slow-Stroke Back Massage on the Anxiety Levels of Iranian Women on the First Postpartum Day

Background

Anxiety disorder is common during the postpartum period. Back massage relaxation techniques are one of the most important nonpharmacological interventions to prevent and control postpartum-related anxiety.

Objectives

To determine the effectiveness of slow-stroke back massage on the anxiety levels of primiparous mothers in the first days after delivery.

Materials and Methods

This single-blind controlled clinical trial consisted of 100 primiparous mothers with normal deliveries. The mothers were randomly allocated to interventional (n = 50) or control (n = 50) groups using binary blocks. Both groups were followed up just before, immediately after, and the morning after the intervention. Data were collected using a demographic questionnaire and Spielberger’s state anxiety inventory (STAI) questionnaire.

Results

The mean age of the mothers was 22 years. There were no significant between-group differences in age (P = 0.333), education (P = 0.427), and medication during labor and the postpartum period (P = 0.412). There was no statistically significant difference between the mean anxiety scores of the experimental (6.66 ± 35.48) and control groups (9.05 ± 37.42) before the intervention (P = 0.268). Immediately after the massage and the next morning, there was a significant between-group difference in the anxiety scores (P < 0.001).

Conclusions

The findings demonstrate that slow-stroke back massage is a simple, inexpensive, noninvasive, and effective method to reduce the anxiety levels of primiparous women during the first postpartum day.

Using senses to encourage head and upper limb voluntary movement in young infants: Implications for early intervention

PRIMARY OBJECTIVE

It has long been suggested that a neonate's movement and responses to external stimuli are the product of reflexive reactions rather than purposeful movements. However, several studies have demonstrated that this is not the case. Rationale of literature included: This study seeks to review reports showing that sensory stimuli resulted in newborns recognising and responding to different stimuli with active head or upper limb movements. We also discuss this in the context of current literature about early training on the advancement of movement and brain development. Results and outcomes: Taken together, it is clear that early active experience shapes learning in newborns.

CONCLUSIONS

The impact of this research is most exciting for applications that would induce infants to make purposeful movements, especially as a means for early intervention and rehabilitation for the treatment of infants with or at high risk for developmental delay.

Physiological mechanisms, behavioral and psychological factors influencing the transfer of milk from mothers to their young

This article is part of a Special Issue "Parental Care".Producing milk to support the growth of their young is a central element of maternal care in mammals. In spite of the facts that ecological constraints influence nursing frequency, length of time until weaning and the composition of milk, there is considerable similarity in the anatomy and physiology of milk production and delivery across mammalian species. Here we provide an overview of cross species variation in nursing patterns and milk composition as well as the mechanisms underlying mammary gland development, milk production and letdown. Not all women breastfeed their infants, thus in later sections we review studies of factors that facilitate or impede the initiation and duration of breastfeeding. The results of these investigations suggest that the decisions to initiate and maintain breastfeeding are influenced by an array of personal, social and biological factors. Finally, studies comparing the development of breastfed and formula fed infants as well as those investigating associations between breastfeeding, maternal health and mother/infant interaction are reviewed. Leading health agencies including the World Health Organization and CDC advocate breastfeeding for at least the first 6months postpartum. To achieve these rates will require not only institutional support but also a focus on individual mother/infant dyads and their experience.

Weight loss and low age are associated with intensity of rooting behaviours in newborn infants

AIM

Little is known about the developing breastfeeding behaviour of newborn infants. This study describes infants' prebreastfeeding behaviour during the second day of life and explores possible associations with infant characteristics.

METHODS

We studied 13 mothers and healthy full-term infants after normal births. At 24-48 hours of life, the newborns were placed in skin-to-skin contact with their mothers for breastfeeding and were video-filmed. The order, frequency and duration of predefined infant prefeeding behaviours and suckling were coded and analysed using computer-based video software.

RESULTS

Prefeeding behaviours occurred in the following order: rooting, hand to mouth movements, licking of the nipple and hand to breast to mouth movements. The infants started to suckle at a median of one to two minutes. Rooting was the most common behaviour, observed in 12 infants. The duration of rooting movements during the last minute before breastfeeding was inversely related to neonatal age (p ≤ 0.001) and positively related to neonatal weight loss (p = 0.02) after birth.

CONCLUSION

Infants exhibited a distinct sequence of prefeeding behaviours during the second day of life, and our findings suggest that rooting movements were governed by mechanisms involved in the regulation of food intake and weight gain.

Responsiveness of human neonates to the odor of 5α-androst-16-en-3-one: a behavioral paradox?

The odorous steroid 5α-androst-16-en-3-one (AND) occurs in numerous biological fluids in mammals, including man, where it is believed to play a chemocommunicative role. As AND was recently detected in milk and amniotic fluid, sensitivity and hedonic responses to this substance were assessed in human neonates. To this aim, respiration and facial expressions were recorded in 3-day-old newborns in response to aqueous solutions of AND, ranging from 500ng/mL to 0.5 fg/mL. Although analyses of respiratory rate did not lead to clear-cut results, the newborns changed their facial expressions at concentrations not detected by adults in a triangle test. Newborns displayed negative facial actions of longer duration to AND relative to an odorless control. Thus, AND may be considered to be offensive to newborns, which is a counterintuitive outcome as they are exposed to this compound in the womb (and it should therefore be familiar), in milk, and on the mother's skin surface (and it should therefore be conditioned as positive). Multiple reasons for this perceptual-behavioral paradox are discussed.

Always follow your nose: the functional significance of social chemosignals in human reproduction and survival

This article is part of a Special Issue "Chemosignals and Reproduction" Across phyla, chemosensory communication is crucial for mediating a variety of social behaviors, which form the basis for ontogenetic and phylogenetic survival. In the present paper, evidence on chemosensory communication in humans, with special reference to reproduction and survival, will be presented. First, the impact of chemosignals on human reproduction will be reviewed. Work will be presented, showing how chemosensory signals are involved in mate choice and partnership formation by communicating attractiveness and facilitating a partner selection, which is of evolutionary advantage, and furthermore providing information about the level of sexual hormones. In addition to direct effects on phylogenetic survival, chemosignals indirectly aid reproductive success by fostering harm protection. Results will be presented, showing that chemosensory communication aids the emotional bond between mother and child, which in turn motivates parental caretaking and protection, leading to infant survival. Moreover, the likelihood of group survival can be increased through the use of stress-related chemosignals. Stress-related chemosignals induce a stress-related physiology in the perceiver, thereby priming a fight-flight-response, which is necessary for an optimum adaption to environmental harm. Finally, effects of sexual orientation on chemosensory communication will be discussed in terms of their putative role in stabilizing social groups, which might indirectly provide harm protection and foster survival. An integrative model of the presented data will be introduced. In conclusion, an outlook, focusing on the involvement of chemosensory communication in human social behavior and illustrating a novel approach to the significance of chemosensory signals in human survival, will be given.

The effects of olfactory stimulation and gender differences on pain responses in full-term infants

AIM

Studies have reported conflicting findings on whether different smells can reduce distress when infants undergo painful procedures. Our study assessed the impact of vanilla on infants' responses to a painful toe lance, including possible gender differences.

METHODS

We measured the pain responses of 69 full-term infants - 34 girls and 35 boys - during toe lance, using two multidimensional scales - the Neonatal Facial Coding System and Behavioural Indicators of Infant Pain - together with crying duration and hand movements. Three sets of data were collected during baseline, toe lance and recovery, while the babies were exposed to the odour of vanilla (n = 39) or odourless water (n = 30).

RESULTS

Pain responses increased significantly during toe lance, then declined during recovery. Crying duration correlated significantly with finger splaying/fisting and both pain scale scores, with boys displaying higher pain scores than girls. Vanilla had no impact on pain levels.

CONCLUSION

Crying and finger splaying/fisting were observable responses that may be useful for screening pain or distress in healthy neonates. Increased pain reactions by boys may reflect higher irritability. Exposure to an unfamiliar odour did not have a calming effect on full-term neonates.

Olfactory event-related potentials in infants

OBJECTIVES

To evaluate olfactory event-related potentials (OERPs) as an objective measurement of olfactory function in infants.

STUDY DESIGN

OERPs to phenylethyl alcohol were measured in 13 infants, between 23 and 41 days of age. The odor was delivered with a computer-controlled olfactometer. Recording electrodes were applied using the 10-20 system. Data from electrodes Fz, Cz, Pz, C3, and C4 were analyzed by MatLab's Letswave toolbox (André Mouraux, Brussels, Belgium) using the canonical time-domain averaging as well as the time-frequency analyzing method.

RESULTS

Ten of 13 infants finished the recording session. We observed OERPs in 7 of these 10 infants. Recordings were best in electrodes Fz and Cz. The N1 peak was visible at 328 ms followed by P2 at 505 ms. In addition, the time-frequency analysis had an increase in low frequencies (4-7 Hz) around 550 ms after odor presentation.

CONCLUSIONS

We were able to record OERPs in infants. The time-domain averaging as well as the time-frequency analysis was of value for data analysis.

Antenatal insults modify newborn olfactory function by nitric oxide produced from neuronal nitric oxide synthase

Newborn feeding, maternal, bonding, growth and wellbeing depend upon intact odor recognition in the early postnatal period. Antenatal stress may affect postnatal odor recognition. We investigated the exact role of a neurotransmitter, nitric oxide (NO), in newborn olfactory function. We hypothesized that olfactory neuron activity depended on NO generated by neuronal NO synthase (NOS). Utilizing in vivo functional manganese enhanced MRI (MEMRI) in a rabbit model of cerebral palsy we had shown previously that in utero hypoxia-ischemia (H-I) at E22 (70% gestation) resulted in impaired postnatal response to odorants and poor feeding. With the same antenatal insult, we manipulated NO levels in the olfactory neuron in postnatal day 1 (P1) kits by administration of intranasal NO donors or a highly selective nNOS inhibitor. Olfactory function was quantitatively measured by the response to amyl acetate stimulation by MEMRI. The relevance of nNOS to normal olfactory development was confirmed by the increase of nNOS gene expression from fetal ages to P1 in olfactory epithelium and bulbs. In control kits, nNOS inhibition decreased NO production in the olfactory system and increased MEMRI slope enhancement. In H-I kits the MEMRI slope did not increase, implicating modification of endogenous NO-mediated olfactory function by the antenatal insult. NO donors as a source of exogenous NO did not significantly change function in either group. In conclusion, olfactory epithelium nNOS in newborn rabbits probably modulates olfactory signal transduction. Antenatal H-I injury remote from delivery may affect early functional development of the olfactory system by decreasing NO-dependent signal transduction.

Early skin-to-skin contact for mothers and their healthy newborn infants

BACKGROUND

Mother-infant separation postbirth is common in Western culture. Early skin-to-skin contact (SSC) begins ideally at birth and involves placing the naked baby, head covered with a dry cap and a warm blanket across the back, prone on the mother's bare chest. According to mammalian neuroscience, the intimate contact inherent in this place (habitat) evokes neurobehaviors ensuring fulfillment of basic biological needs. This time may represent a psychophysiologically 'sensitive period' for programming future physiology and behavior.

OBJECTIVES

To assess the effects of early SSC on breastfeeding, physiological adaptation, and behavior in healthy mother-newborn dyads.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 November 2011), made personal contact with trialists, and consulted the bibliography on kangaroo mother care (KMC) maintained by Dr. Susan Ludington.

SELECTION CRITERIA

Randomized controlled trials comparing early SSC with usual hospital care.

DATA COLLECTION AND ANALYSIS

We independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Thirty-four randomized controlled trials were included involving 2177 participants (mother-infant dyads). Data from more than two trials were available for only eight outcome measures. For primary outcomes, we found a statistically significant positive effect of early SSC on breastfeeding at one to four months postbirth (13 trials; 702 participants) (risk ratio (RR) 1.27, 95% confidence interval (CI) 1.06 to 1.53, and SSC increased breastfeeding duration (seven trials; 324 participants) (mean difference (MD) 42.55 days, 95% CI -1.69 to 86.79) but the results did not quite reach statistical significance (P = 0.06). Late preterm infants had better cardio-respiratory stability with early SSC (one trial; 31 participants) (MD 2.88, 95% CI 0.53 to 5.23). Blood glucose 75 to 90 minutes following the birth was significantly higher in SSC infants (two trials, 94 infants) (MD 10.56 mg/dL, 95% CI 8.40 to 12.72).The overall methodological quality of trials was mixed, and there was high heterogeneity for some outcomes.

AUTHORS' CONCLUSIONS

Limitations included methodological quality, variations in intervention implementation, and outcomes. The intervention appears to benefit breastfeeding outcomes, and cardio-respiratory stability and decrease infant crying, and has no apparent short- or long-term negative effects. Further investigation is recommended. To facilitate meta-analysis, future research should be done using outcome measures consistent with those in the studies included here. Published reports should clearly indicate if the intervention was SSC with time of initiation and duration and include means, standard deviations and exact probability values.

Sex differences in newborn interaction with mother or father during skin-to-skin contact after Caesarean section

AIM

To investigate differences between the breast-seeking and crying behaviour of girls and boys in skin-to-skin contact (SSC) with their mother or their father after Caesarean section as well as the point-in-time for the first breastfeeding and to compare mothers' and fathers' interactive behaviour with their newborn girl or boy.

METHODS

Twenty girls and 17 boys were randomized to 25 min of SSC with one or the other parent immediately after birth. The interaction was videotaped.

RESULTS

Girls started rooting movements earlier than boys in SSC with either parent (p = 0.027). Infants started to breastfeed significantly earlier if having been in SSC with mothers compared with SSC with fathers during the first 5-30 min (p = 0.018). Girls cried more than boys in SSC with either parent (p = 0.02). Mothers used more touching behaviour towards their newborn infant than fathers (p = 0.001). Mothers touched girls less than boys (p = 0.038). Fathers directed less speech towards girls compared with boys (p = 0.042).

CONCLUSION

Early mother-infant SSC immediately after Caesarean section should be promoted until the occurrence of the first breastfeed. If the mother is unable to provide SSC immediately after birth, the father-infant SSC is a valuable alternative because it enhances paternal interaction.

[The mother-infant encounter at birth must be protected]

The medical decision to separate a newborn baby from his or her mother is frequent. This medical practice must be evaluated. The scientific literature regarding humans and other mammals was reviewed in order to describe the physiology of the interactions between mother and offspring and the consequences of disrupting their interactions around birth. Mother-infant bonding is common to all mammals. Attachment is the result of three mechanisms: behavioral programing, secretion of neuroendocrine substrates, and activation of sensory cues. Breastfeeding is a fourth component that plays a crucial role. Experimental research provides evidence that early-life maternal separation can alter biological responses to stress, disturb learning behaviors, and impair social skills. Recent advances in epigenetic research may partly explain how neonatal maternal deprivation at birth can lead to biological and behavioral disorders in adulthood. Therefore, the decision to separate a newborn infant from his or her mother is not harmless and must be carefully considered. In order to better take into account these data, the organization of perinatal care in France should be revised.

The Psychological Effects of Aromatherapy-Massage in Healthy Postpartum Mothers

This study examined the effect of aromatherapy-massage in healthy postpartum mothers. A quasi-experimental between-groups design was used. Mothers who received aromatherapy-massage were compared with a control group who received standard postpartum care. Thirty-six healthy, first-time mothers with vaginal delivery of a full-term, healthy infant participated in this study. Sixteen mothers received a 30-minute aromatherapy-massage on the second postpartum day; 20 mothers were in the control group. All mothers completed the following four standardized questionnaires before and after the intervention: 1) Maternity Blues Scale; 2) State-Trait Anxiety Inventory; 3) Profile of Mood States (POMS); and 4) Feeling toward Baby Scale. In the aromatherapy-massage group, posttreatment scores significantly decreased for the Maternity Blues Scale, the State-Anxiety Inventory, and all but one of the Profile of Mood States subscales. Posttreatment scores in the intervention group significantly increased in Profile of Mood States-Vigor subscale and the Approach Feeling toward Baby subscale. Scores in the intervention group significantly decreased in Conflict Index of Avoidance/Approach Feeling toward Baby subscale. Our results suggest that aromatherapy-massage might be an effective intervention for postpartum mothers to improve physical and mental status and to facilitate mother-infant interaction.

Fetal learning about ethanol and later ethanol responsiveness: evidence against "safe" amounts of prenatal exposure

Near-term fetuses of different mammalian species, including humans, exhibit functional sensory and learning capabilities. The neurobiological literature indicates that the unborn organism processes sensory stimuli present in the amniotic fluid, retains this information for considerable amounts of time, and is also capable of associating such stimuli with biologically relevant events. This research has stimulated studies aimed at the analysis of fetal and neonatal learning about ethanol, a topic that constitutes the core of the present review. Ethanol has characteristic sensory (olfactory, taste, and trigeminal) attributes and can exert pharmacologic reinforcing effects. The studies under examination support the hypothesis that low to moderate levels of maternal ethanol intoxication during late pregnancy set the opportunity for fetal learning about ethanol. These levels of prenatal ethanol exposure do not generate evident morphologic or neurobehavioral alterations in the offspring, but they exert a significant impact upon later ethanol-seeking and intake behaviors. Supported by preclinical and clinical findings, this review contributes to strengthening the case for the ability of prenatal ethanol exposure to have effects on the postnatal organism.

The development of potentially better practices to support the neurodevelopment of infants in the NICU

OBJECTIVE

To review the existing evidence used to identify potentially better care practices that support newborn brain development.

STUDY DESIGN

Literature review.

RESULT

Sixteen potentially better practices are identified and grouped into two operational clinical bundles based upon timing for recommended implementation.

CONCLUSION

Existing evidence supports the implementation of selected care practices that potentially may support newborn brain development.

Breast milk odor via olfactometer for tube-fed, premature infants

Human newborns use odor cues to orient to their source of nutrition. However, tube-fed, premature infants have restricted chemosensory experience. New methods of introducing breast milk odor to tube-fed premature infants will permit empiric tests of the effect of controlled exposure to nutrient odor. We therefore developed an infant olfactometer and piloted its use in 7 tube-fed, premature infants in the neonatal intensive care unit. Since nonnutritive sucking shortens the amount of time required to wean from tube-feeding, we tested the effect of breast milk odor on nonnutritive sucking. Six out of 7 subjects responded to breast milk odor with an increase in number of sucks. Statistical analysis supported the hypothesis that breast milk odor reinforces nonnutritive sucking. These results indicate the feasibility and potential of this experimental approach, and warrant further study of the effect of controlled nutrient odor exposure on feeding behavior of premature infants.

Early skin-to-skin contact for mothers and their healthy newborn infants

BACKGROUND

Mother-infant separation postbirth is common in Western culture. Early skin-to-skin contact (SSC) begins ideally at birth and involves placing the naked baby, covered across the back with a warm blanket, prone on the mother's bare chest. According to mammalian neuroscience, the intimate contact inherent in this place (habitat) evokes neurobehaviors ensuring fulfillment of basic biological needs. This time may represent a psychophysiologically 'sensitive period' for programming future behavior.

OBJECTIVES

To assess the effects of early SSC on breastfeeding, behavior, and physiological adaptation in healthy mother-newborn dyads.

SEARCH STRATEGY

Cochrane Pregnancy and Childbirth Group's and Neonatal Group's Trials Registers (August 2006), Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, Issue 2), MEDLINE (1976 to 2006).

SELECTION CRITERIA

Randomized and quasi-randomized clinical trials comparing early SSC with usual hospital care.

DATA COLLECTION AND ANALYSIS

We independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Thirty studies involving 1925 participants (mother-infant dyads), were included. Data from more than two trials were available for only 8-of-64 outcome measures. We found statistically significant and positive effects of early SSC on breastfeeding at one to four months postbirth (10 trials; 552 participants) (odds ratio (OR) 1.82, 95% confidence interval (CI) 1.08 to 3.07), and breastfeeding duration (seven trials; 324 participants) (weighted mean difference (WMD) 42.55, 95% CI -1.69 to 86.79). Trends were found for improved summary scores for maternal affectionate love/touch during observed breastfeeding (four trials; 314 participants) (standardized mean difference (SMD) 0.52, 95% CI 0.07 to 0.98) and maternal attachment behavior (six trials; 396 participants) (SMD 0.52, 95% CI 0.31 to 0.72) with early SSC. SSC infants cried for a shorter length of time (one trial; 44 participants) (WMD -8.01, 95% CI -8.98 to -7.04). Late preterm infants had better cardio-respiratory stability with early SSC (one trial; 35 participants) (WMD 2.88, 95% CI 0.53 to 5.23). No adverse effects were found.

AUTHORS' CONCLUSIONS

Limitations included methodological quality, variations in intervention implementation, and outcome variability. The intervention may benefit breastfeeding outcomes, early mother-infant attachment, infant crying and cardio-respiratory stability, and has no apparent short or long-term negative effects. Further investigation is recommended. To facilitate meta-analysis, future research should be done using outcome measures consistent with those in the studies included here. Published reports should clearly indicate if the intervention was SSC and include means, standard deviations, exact probability values, and data to measure intervention dose.

The calming effect of a familiar odor on full-term newborns

We assessed the effectiveness of an odor (familiar or unfamiliar) in soothing healthy full-term newborns undergoing a routine heel stick. Forty-four breast-fed newborns were randomly assigned to one of four groups: Before the heel stick, Group 1 was naturally familiarized with their mother's milk odor, Group 2 was familiarized with a vanilla smell, and Groups 3 and 4 did not receive any familiarization. During and after the heel stick, Group 1 was presented with their mother's milk odor, Group 2 was presented with the familiar vanilla, Group 3 was presented with an unfamiliar odor, and Group 4 was a control group. Infants' crying, grimacing, and head movements were analyzed before, during, and after the heel stick. Results show that infants who smelled a familiar odor (their mother's milk or vanilla) cried and grimaced significantly less during the recovery phase compared with the heel stick phase. Infants who were presented with an unfamiliar odor or no odor showed no significant changes during recovery. Moreover, infants who smelled their mother's milk exhibited significantly less motor agitation during the heel stick compared with the other groups. These findings indicate that smelling a familiar odor reduces agitation during the heel stick and diminishes distress after the procedure.

Antenatal olfactory learning influences infant feeding

The aim is to know whether antenatal olfactory learning have a greater effect than postnatal olfactory learning on infant feeding even in the absence of triggering signals. We evaluated the sucking behavior of infants completely separated from their mothers for 10-14 days since birth. The 12 infants admitted to Chiba Children's Hospital were studied at 10-14 days of age. Oral feeding was initiated at 4-7 days of age. The sucking and expression pressures, frequency, and sucking efficiency were measured during bottle-feeding with exposure to odors of mother's milk, formula, and water. The mother's milk odor elicited more frequent sucking with higher expression pressure than did formula or water. In conclusion, the odor preferences acquired independently from postnatal experience may have a greater effect than postnatal olfactory learning on sucking activity.

Early skin-to-skin contact for mothers and their healthy newborn infants

BACKGROUND

Early skin-to-skin contact involves placing the naked baby prone on the mother's bare chest at birth or soon afterwards (< 24 hour). This could represent a 'sensitive period' for priming mothers and infants to develop a synchronous, reciprocal, interaction pattern, provided they are together and in intimate contact. Routine separation shortly after hospital birth is a uniquely Western cultural phenomenon that may be associated with harmful effects including discouragement of successful breastfeeding.

OBJECTIVES

To assess the effects of early skin-to-skin contact on breastfeeding, behavior, and physiology in mothers and their healthy newborn infants.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group and Neonatal Group trials registers (December 2002), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 4, 2002), MEDLINE (1976 to 2002).

SELECTION CRITERIA

Randomized and quasi-randomized clinical trials comparing early skin-to-skin contact with usual hospital care.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. We contacted study authors for additional information. We collected adverse effects information from the trials.

MAIN RESULTS

Seventeen studies, involving 806 participants, were included. We found statistically significant and positive effects of early skin-to-skin contact on breastfeeding at one to three months postbirth (odds ratio (OR) 2.15, 95% confidence interval (CI) 1.10 to 4.22), breastfeeding duration (weighted mean difference (WMD) 41.99, 95% CI 13.97 to 70.00), maintenance of infant temperature in the neutral thermal range (OR 12.18, 95% CI 2.04 to 72.91), infant blood glucose (WMD 11.07, 95% CI 3.97 to 18.17), infant crying (OR 21.89, 95% CI 5.19 to 92.30) and summary scores of maternal affectionate love/touch (SMD 0.73, 95% CI 0.36 to 1.11) during an observed breastfeeding within the first few days postbirth. We found no statistically significant benefit of early skin-to-skin contact for other major clinical variables: breastmilk maturation, maternal chest circumference, infant heart rate.

REVIEWER'S CONCLUSIONS

Limitations included the methodological quality of the studies, variations in the implementation of the intervention and outcome variability. Early skin-to-skin contact appears to have some clinical benefit especially regarding breastfeeding outcomes and infant crying and has no apparent short or long-term negative effects. Further investigation is recommended. To facilitate meta-analysis of the data, future research in this area should involve outcome measures consistent with those used in the studies included here. Published reports should also clearly indicate if the intervention was skin-to-skin contact and include means, standard deviations and exact probability values.

Cerebral hemodynamic response to unpleasant odors in the preterm newborn measured by near-infrared spectroscopy

Newborn infants in intensive care units are exposed to several unfamiliar smells, mostly related to the nosocomial environment. How the preterm baby perceives these olfactory stimulations remains unclear. Near-infrared spectroscopy can be performed noninvasively above the olfactory cortex to monitor changes of cerebral blood flow as an indicator of cortical activation. The aim of this study was to explore by near-infrared spectroscopy how odorous substances routinely used in the neonatal intensive care unit influence bilateral cortical hemodynamics in the olfactory region of the brains of preterm infants. Specifically, a detergent (Neomidil) and an adhesive remover (Remove) have been tested. Twenty preterm neonates of gestational age 30-37 wk (mean 33.7 +/- 2.3 SD) and postconceptional age 32-37.3 wk (mean 35.5 +/- 2.75 SD) were monitored by near-infrared spectroscopy. Two optode pairs were placed above the anterior orbitofrontal gyri, which is involved in olfactory processing, on each side of the skull. Fifteen babies were exposed to the smell of a disinfectant and five babies to that of a detergent, both applied to small cotton pads. Changes of oxygenated Hb and deoxygenated Hb were recorded before, during, and after a 10-s stimulus. In 17 out of 20 babies, there was a decrease in oxygenated Hb and total Hb after the exposure to the substances. The decrease was significantly greater in the right side than in the left side. This change was different from that observed in our previous study after exposure to colostrum and the pleasant smell of vanilla, which elicited an increase in blood oxygenation in the same region. The biologic significance of this finding is unknown. We conclude that cortical hemodynamic modifications occur in the preterm newborn after exposure to preparations commonly used in the neonatal intensive care unit. A lateralization seems to occur in processing unpleasant olfactory cues.

Differential responsiveness to alcohol odor in human neonates: effects of maternal consumption during gestation

Previous human and animal studies have shown that specific memories arise during prenatal life as a function of fetal processing of chemosensory stimuli present in the amniotic fluid. Furthermore, the animal literature indicates that fetal exposure to alcohol modifies subsequent neonatal and infantile responsiveness toward the sensory attributes of the drug. The main goal of the present study was to analyze whether differential maternal alcohol consumption during pregnancy affects neonatal reactivity to ethanol odor. To achieve this goal, an initial experiment examined how healthy human neonates respond to olfactory stimuli. In this first experiment, newborns (postpartum age: 24-48 h) were evaluated in terms of motor responsiveness elicited by repetitive stimulation with either alcohol or lemon odors. Infants exhibited a marked increase in duration of overall body and head and facial activity when the odorants were first presented. In four successive trials, behavioral responsiveness progressively declined until reaching baseline values. The introduction of a novel odorant served to dishabituate the motor responses under analysis. In the second experiment newborn's reactivity to the mentioned odorants was evaluated as a function of maternal self-reported patterns of consumption of alcohol during gestation. Mothers were classified as frequent or infrequent drinkers. Babies born to frequent drinkers exhibited heightened reactivity toward ethanol odor when compared to newborns delivered by infrequent drinkers. No differences emerged when comparing the responses of both groups of infants elicited by a non-ethanol stimulus such as lemon. The results coupled with prior human and animal research suggest the possibility of intrauterine experience with alcohol odor that yields a sensory memory likely to be retrieved immediately after birth.

Food choice and intake: the human factor

Human perceptions and selection of food are derived from the prevailing and momentary food, agro-economic and cultural environment, cognitive and biological characteristics of individuals, and the real and perceived intrinsic and extrinsic attributes of foods themselves. The range of items typically chosen and consumed within a given population is largely determined by interaction of the external environmental context with guiding sets of implicit and explicit social and psychobiological 'rules'. Within the rather broad limits of biology, individual food choices and intake behaviours relate to and reflect aspects of food availability, existing habitual behaviours, learning mechanisms, and individual beliefs and expectations. Many of the relevant features of these variables are uniquely human, together determining what is 'food', when, how, by and with whom it is chosen and eaten, and in what quantities. They also provide the opportunities for individuals to establish and maintain a relatively stable set of culturally and biologically determined affective responses ('likes') and intake behaviours. Understanding of the potential contribution of these influences under different conditions can serve to explain many of the observed characteristics of human eating, and highlight potential avenues for intervention.

Unique salience of maternal breast odors for newborn infants

Human infants are particularly responsive to olfactory cues emanating from their mother's nipple/areola region. Beginning within minutes after birth, maternal breast odors elicit preferential head orientation by neonates and help guide them to the nipple. Such odors also influence babies' general motor activity and arousal, which may contribute further to successful nipple localization and sucking. The role of maternal olfactory signals in the mediation of early breast-feeding is functionally analogous to that of nipple-search pheromone as described in nonhuman mammals. To some extent, the chemical profile of breast secretions overlaps with that of amniotic fluid. Therefore, early postnatal attraction to odors associated with the nipple/areola may reflect prenatal exposure and familiarization. Although newborns are generally attracted to breast odors produced by lactating women, breast-fed infants rapidly learn their mother's characteristic olfactory signature while sucking at her breasts and can subsequently recognize her by that unique scent alone. Early odor-based recognition may be an important factor in the development of the infant-mother bond.