Individual Infants Research Articles

Individual variability in the nonlinear development of the corpus callosum during infancy and toddlerhood: a longitudinal MRI analysis.

The human brain spends several years bootstrapping itself through intrinsic and extrinsic modulation, thus gradually developing both spatial organization and functions. Based on previous studies on developmental patterns and inter-individual variability of the corpus callosum (CC), we hypothesized that inherent variations of CC shape among infants emerge, depending on the position within the CC, along the developmental timeline. Here we used longitudinal magnetic resonance imaging data from infancy to toddlerhood and investigated the area, thickness, and shape of the midsagittal plane of the CC by applying multilevel modeling. The shape characteristics were extracted using the Procrustes method. We found nonlinearity, region-dependency, and inter-individual variability, as well as intra-individual consistencies, in CC development. Overall, the growth rate is faster in the first year than in the second year, and the trajectory differs between infants; the direction of CC formation in individual infants was determined within six months and maintained to two years. The anterior and posterior subregions increase in area and thickness faster than other subregions. Moreover, we clarified that the growth rate of the middle part of the CC is faster in the second year than in the first year in some individuals. Since the division of regions exhibiting different tendencies coincides with previously reported divisions based on the diameter of axons that make up the region, our results suggest that subregion-dependent individual variability occurs due to the increase in the diameter of the axon caliber, myelination partly due to experience and axon elimination during the early developmental period.

Recognizing Our Biases, Understanding the Evidence, and Responding Equitably: Application of the Socioecological Model to Reduce Racial Disparities in the NICU.

Implicit bias permeates beliefs and actions both personally and professionally and results in negative health outcomes for people of color-even in the neonatal intensive care unit (NICU). NICU clinicians may naïvely and incorrectly assume that NICU families receive unbiased care. Existing evidence establishing associations between sex, race, and neonatal outcomes may perpetuate the tendency to deny racial bias in NICU practice. Using the socioecological model as a framework, this article outlines evidence for racial health disparities in the NICU on multiple levels-societal, community, institutional, interpersonal, and individual. Using current evidence and recommendations from the National Association of Neonatal Nurses Position Statement on "Racial Bias in the NICU," appropriate interventions and equitable responses of the NICU clinician are explored. Based on current evidence, clinicians should reject the notion that the social construct of race is the root cause for certain neonatal morbidities. Instead, clinicians should focus on the confluence of medical and social factors contributing to each individual infant's progress. This critical distinction is not only important for clinicians employing life-saving interventions, but also for those who provide routine care, developmental care, and family education-as these biases can and do shape clinical interactions. Healthcare practitioners have an ethical and moral responsibility to maintain up-to-date knowledge of new evidence that impacts our clinical practice. The evidence demonstrates the importance of recognizing the enduring role of racism in the health and well-being of people of color and the need to adjust care accordingly.

Model for severe intracranial hemorrhage and role of early indomethacin in extreme preterm infants.

To develop a model for prediction of severe intracranial hemorrhage (ICH) or death based on variables from the first 12 h of age and to compare mortality and morbidities with and without exposure to early indomethacin. This retrospective cohort study included extreme preterm (220/7-266/7 weeks) infants born at National Institute of Child Health and Human Development Neonatal Research Network sites. Primary outcome was a composite of severe ICH and/or death. Of 4624 infants, 1827 received early indomethacin. Lower gestation, lack of antenatal steroids exposure, lower 1-min Apgar, male sex, and receipt of epinephrine were associated with severe ICH or death. Early indomethacin was associated with a lower risk of patent ductus arteriosus, bronchopulmonary dysplasia, and higher risk of spontaneous intestinal perforation. A model for early prediction of severe ICH/death was developed and validated. Early indomethacin was associated with a lower risk of patent ductus arteriosus and bronchopulmonary dysplasia and a higher risk of spontaneous intestinal perforation. Not applicable. Modern data on severe ICH and neonatal morbidities in relation to prophylactic indomethacin are scarce in the published literature. Prophylactic indomethacin was associated with a lower risk of patent ductus arteriosus and bronchopulmonary dysplasia and a higher risk of intestinal perforation. A risk estimator for severe intracranial hemorrhage/death was developed in a large cohort of extremely preterm infants. The risk estimator developed based on a large cohort of patients provides an estimate of severe intracranial bleeding for an individual infant.

In vitro fermentation of human milk oligosaccharides by individual Bifidobacterium longum-dominant infant fecal inocula

This study investigated the fermentation characteristics and microbial responses of human milk oligosaccharides (HMOs) by individual Bifidobacterium longum-dominant infant fecal microbiota. Fucosylated neutral HMOs (2′-fucosyllactose, 2′-FL; 3-fucosyllactose, 3-FL), sialylated HMOs (3′-sialyllactose, 3′-SL; 6′-sialyllactose, 6′-SL), and non-fucosylated neutral HMOs (Lacto-N-tetraose, LNT; Lacto-N-neotetraose, LNnT) were fermented in vitro, with fructooligosaccharides (FOS) and galactooligosaccharides (GOS) as positive controls. The fermentation rate was not affected by the molecular specificity of HMOs. Acetate (98–104 mM) and lactate (9–19 mM) were the primary metabolites at the end of fermentation. All six HMOs showed the same levels of acetate production, but sialylated HMOs produced significantly less lactate than neutral HMOs. HMOs and GOS could maintain the dominance or increase the relative abundance of Bifidobacterium longum, while FOS remarkably promote Klebsiella pneumoniae with the highest gas production and the least acetate and lactate yield. The findings are supportive to optimize infant nutrition strategies for enhanced functions.

Starting and Increasing Feeds, Milk Tolerance and Monitoring of Gut Health in Significantly Preterm Infants.

Approaches to enteral feeding significantly preterm infants' impact short-term outcomes including survival, late-onset sepsis (LOS), and necrotizing enterocolitis (NEC), and neurodevelopmental and later health outcomes. Clinical practice and trial data are dominated by short-term outcomes (NEC and LOS) with limited longer-term outcomes. Strategies maximizing early maternal breast milk (MOM) exposure and duration of MOM use are key given global health benefits of MOM, but few feeding trials use these as outcomes. Current data support colostrum receipt, early introduction, and progression of volumes between 18 and 30 mL/kg/day, without adverse impact on NEC, LOS, or mortality. Little evidence supports choosing between route of gastric tube placement, bolus, or continuous feed delivery. Individual infants may have specific features that require individualized feed management, such as combinations of growth restriction, antenatal blood flow concerns, intensive supportive needs (including inotropes), and large open patent ductus arteriosus, currently poorly represented in feeding trials. Infant tolerance monitoring includes clinical observations (stooling, abdominal size, vomiting) but routine gastric aspiration appears unhelpful. Infants should be monitored biochemically, anthropometrically, and in the future through bedside microbiomics or metabolomics. Units and networks should audit and compare their rates of mortality, NEC, LOS, neurodevelopment, and growth achieved.

The impact of premature extrauterine exposure on infants’ stimulus-evoked brain activity across multiple sensory systems

Prematurity can result in widespread neurodevelopmental impairment, with the impact of premature extrauterine exposure on brain function detectable in infancy. A range of neurodynamic and haemodynamic functional brain measures have previously been employed to study the neurodevelopmental impact of prematurity, with methodological and analytical heterogeneity across studies obscuring how multiple sensory systems are affected. Here, we outline a standardised template analysis approach to measure evoked response magnitudes for visual, tactile, and noxious stimulation in individual infants (n = 15) using EEG. By applying these templates longitudinally to an independent cohort of very preterm infants (n = 10), we observe that the evoked response template magnitudes are significantly associated with age-related maturation. Finally, in a cross-sectional study we show that the visual and tactile response template magnitudes differ between a cohort of infants who are age-matched at the time of study but who differ according to whether they are born during the very preterm or late preterm period (n = 10 and 8 respectively). These findings demonstrate the significant impact of premature extrauterine exposure on brain function and suggest that prematurity can accelerate maturation of the visual and tactile sensory system in infants born very prematurely. This study highlights the value of using a standardised multi-modal evoked-activity analysis approach to assess premature neurodevelopment, and will likely complement resting-state EEG and behavioural assessments in the study of the functional impact of developmental care interventions.

Vascular Endothelial Growth Factor Signaling in Models of Oxygen-Induced Retinopathy: Insights Into Mechanisms of Pathology in Retinopathy of Prematurity.

Retinopathy of prematurity (ROP) is a leading cause of blindness in children worldwide. Blindness can occur from retinal detachment caused by pathologic retinal angiogenesis into the vitreous, termed intravitreal neovascularization (IVNV). Although agents that interfere with the bioactivity of vascular endothelial growth factor (VEGF) are now used to treat IVNV, concerns exist regarding the identification of optimal doses of anti-VEGF for individual infants and the effect of broad VEGF inhibition on physiologic angiogenesis in external organs or in the retina of a preterm infant. Therefore, it is important to understand VEGF signaling in both physiologic and pathologic angiogenesis in the retina. In this manuscript, we review the role of receptors that interact with VEGF in oxygen-induced retinopathy (OIR) models that represent features of ROP pathology. Specifically, we discuss our work regarding the regulation of VEGFR2 signaling in retinal endothelial cells to not only reduce severe ROP but also facilitate physiologic retinal vascular and neuronal development.

Mechanisms of social evaluation in infancy: A preregistered exploration of infants' eye-movement and pupillary responses to prosocial and antisocial events.

Past research shows infants selectively touch and look longer at characters who help versus hinder others (Social evaluation by preverbal infants. Nature, 2007, 450, 557; Three-month-olds show a negativity bias in their social evaluations. Developmental Science, 2010, 13, 923); however, the mechanisms underlying this tendency remain underspecified. The current preregistered experiment approaches this question by examining infants' real-time looking behaviors during prosocial and antisocial events, and exploring how individual infants' looking behaviors correlate with helper preferences. Using eye-tracking, 34 five-month-olds were familiarized with two blocks of the "hill" scenario originally developed by Kuhlmeier et al. (Attribution of dispositional states by 12-month-olds. Psychological Science, 2003, 14, 402), in which a climber tries unsuccessfully to reach the top of a hill and is alternately helped or hindered. Infants' visual preferences were assessed after each block of 6helping and hindering events by proportional looking time to the helper versus hinderer in an image of the characters side by side. Results showed that, at the group level, infants looked longer at the helper after viewing 12 (but not after viewing 6) helping and hindering videos. Moreover, individual infants' average preference for the helper was predicted by their looking behaviors, particularly those suggestive of an understanding of the climber's unfulfilled goal. These results shed light on how infants process helping/hindering scenarios, and suggest that goal understanding is important for infants' helper preferences.

Speech token detection and discrimination in individual infants using functional near-infrared spectroscopy

Speech detection and discrimination ability are important measures of hearing ability that may inform crucial audiological intervention decisions for individuals with a hearing impairment. However, behavioral assessment of speech discrimination can be difficult and inaccurate in infants, prompting the need for an objective measure of speech detection and discrimination ability. In this study, the authors used functional near-infrared spectroscopy (fNIRS) as the objective measure. Twenty-three infants, 2 to 10 months of age participated, all of whom had passed newborn hearing screening or diagnostic audiology testing. They were presented with speech tokens at a comfortable listening level in a natural sleep state using a habituation/dishabituation paradigm. The authors hypothesized that fNIRS responses to speech token detection as well as speech token contrast discrimination could be measured in individual infants. The authors found significant fNIRS responses to speech detection in 87% of tested infants (false positive rate 0%), as well as to speech discrimination in 35% of tested infants (false positive rate 9%). The results show initial promise for the use of fNIRS as an objective clinical tool for measuring infant speech detection and discrimination ability; the authors highlight the further optimizations of test procedures and analysis techniques that would be required to improve accuracy and reliability to levels needed for clinical decision-making.

Toward personalized medicine for pharmacological interventions in neonates using vital signs.

Vital signs, such as heart rate and oxygen saturation, are continuously monitored for infants in neonatal care units. Pharmacological interventions can alter an infant's vital signs, either as an intended effect or as a side effect, and consequently could provide an approach to explore the wide variability in pharmacodynamics across infants and could be used to develop models to predict outcome (efficacy or adverse effects) in an individual infant. This will enable doses to be tailored according to the individual, shifting the balance toward efficacy and away from the adverse effects of a drug. Pharmacological analgesics are frequently not given in part due to the risk of adverse effects, yet this exposes infants to the short‐ and long‐term effects of painful procedures. Personalized analgesic dosing will be an important step forward in providing safer effective pain relief in infants. The aim of this paper was to describe a framework to develop predictive models of drug outcome from analysis of vital signs data, focusing on analgesics as a representative example. This framework investigates changes in vital signs in response to the analgesic (prior to the painful procedure) and proposes using machine learning to examine if these changes are predictive of outcome—either efficacy (with pain response measured using a multimodal approach, as changes in vital signs alone have limited sensitivity and specificity) or adverse effects. The framework could be applied to both preterm and term infants in neonatal care units, as well as older children. Sharing vital signs data are proposed as a means to achieve this aim and bring personalized medicine rapidly to the forefront in neonatology.

Abstract 11948: A Standardized Method to Isolate and Purify Cardiomyocytes from Individual Mouse Hearts Irrespective of Postnatal Age

Rational: Primary cardiomyocytes (CMs) are invaluable for understanding postnatal heart development and elucidating disease mechanisms in genetic and pharmacological models, however, a method to obtain freshly purified CMs at any postnatal age, without the need for different age-dependent isolation procedures and cell culture, is lacking. Objective: To develop a standardized method that allows rapid isolation and purification of CMs in high yield and viability from individual neonatal, infant, and adult mice. Methods and Results: Using a novel in situ aortic cannulation procedure optimized to allow cannulation of even the very small vessel of neonates [postnatal day 0-2 (P0-2)], hearts of C57BL/6J mice were subjected to Langendorff retrograde perfusion and enzymatic digestion. After subsequent tissue disaggregation and filtration, CMs were isolated in high yield (1.55-2.2 x 10 6 CMs/heart) and viability (~78%). The larger size of infant (P10 and P13) and adult (P70), but not neonatal CMs, compared to non-myocytes, allowed their further enrichment by differential centrifugation, before purification at the bench by bead-based immunomagnetic cell separation. This involved depletion of endothelial cells (for infant and adult preparations) or non-myocytes (neonatal preparations). Together, these procedures resulted in highly purified CMs (~95%) from hearts of all ages within 1 hour. Moreover, in situ fixation immediately after tissue digestion via coronary perfusion, preserved the cytoarchitecture of isolated CMs (~94% rod-shaped CMs at all postnatal ages), allowing capture of spindle-shaped neonatal cells undergoing mitosis, as well as enabling accurate quantitation of CM area and nucleation state. RNA-sequencing of CMs purified from one P2 male and female heart per litter (n=4 litters) showed distinct clustering by litters rather than by sexes; a finding consistent with cardiac size and shape being indistinguishable between P2 male (n=6) and female (n=6) hearts as determined by micro-computed tomography (X-ray 3D imaging). Conclusion: The procedures developed here provide a universal protocol for the rapid purification of high-quality CMs from individual hearts at any postnatal age, even those of neonates.

A Look Back at Bioethics: William L. Meadow, 1948-2019.

A Look Back at Bioethics: William L. Meadow, 1948-2019.

Apnoea of Prematurity and Neurodevelopmental Outcomes: Current Understanding and Future Prospects for Research.

Infants who are born prematurely are at significant risk of apnoea. In addition to the short-term consequences such as hypoxia, apnoea of prematurity has been associated with long-term morbidity, including poor neurodevelopmental outcomes. Clinical trials have illustrated the importance of methylxanthine drugs, in particular caffeine, in reducing the risk of long term adverse neurodevelopmental outcomes. However, the extent to which apnoea is causative of this secondary neurodevelopmental delay or is just associated in a background of other sequelae of prematurity remains unclear. In this review, we first discuss the pathophysiology of apnoea of prematurity, previous studies investigating the relationship between apnoea and neurodevelopmental delay, and treatment of apnoea with caffeine therapy. We propose a need for better methods of measuring apnoea, along with improved understanding of the neonatal brain's response to consequent hypoxia. Only then can we start to disentangle the effects of apnoea on neurodevelopment in preterm infants. Moreover, by better identifying those infants who are at risk of apnoea, and neurodevelopmental delay, we can work toward a risk stratification system for these infants that is clinically actionable, for example, with doses of caffeine tailored to the individual. Optimising treatment of apnoea for individual infants will improve neonatal care and long-term outcomes for this population.

Peak selection and latency jitter correction in developmental event-related potentials.

Event-related potentials (ERPs) provide great insight into neural responses, yet developmental ERP work is plagued with inconsistent approaches to identifying and quantifying component latency. In this analytical review, we describe popular conventions for the selection of time windows for ERP analysis and assert that a data-driven strategy should be applied to the identification of component latency within individual participants' data. This may overcome weaknesses of more general approaches to peak selection; however, it does not account for trial-by-trial variability within a participant. This issue, known as ERP latency jitter, may blur the average ERP, misleading the interpretation of neural mechanisms. Recently, the ReSync MATLAB toolbox has been made available for correction of latency jitter. Although not created specifically for pediatric ERP data, this approach can be adapted for developmental researchers. We have demonstrated the use of the ReSync toolbox with individual infant and child datasets to illustrate its utility. Details about our peak detection script and the ReSync toolbox are provided. The adoption of data processing procedures that allow for accurate, study-specific component selection and reduce trial-by-trial asynchrony strengthens developmental ERP research by decreasing noise included in ERP analyses and improving the representation of the neural response.

Perspective: Milk microRNAs as Important Players in Infant Physiology and Development

Evolutionary selective pressure on lactation has resulted in milk that provides far more than simply essential nutrients, delivering a complex repertoire of agents from hormones to intact cells. Human infants are born with low barrier integrity of their gut, which means that many of the complex biopolymer components of milk enter and circulate in lymph and blood, reaching organs throughout the body. Due to this state of gut maturation, all components of milk are potentially part of the crosstalk between mother and infants. This article highlights the functions of milk's complex biopolymers, more specifically the potential role of microRNAs (miRNAs) contained in extracellular vesicles in human milk. miRNAs are key effectors in the regulation of many biological processes during early-age development, and consequently milk-sourced miRNAs must be considered to provide unique biological assets to the infant during breastfeeding. This article interprets the evidence of the potential action of human milk miRNAs on infant development, taking into account their abundance in milk based on the literature and current knowledge. Human milk miRNAs appear to influence lipid and glucose metabolism, gut maturation, neurogenesis, and immunity. We also show growing evidence that human milk miRNAs are epigenetic modulators that play a pivotal role in the regulation of tissue-specific gene expression throughout life. Furthermore, this article addresses the ongoing debate regarding the potential influence of human milk miRNAs on viral infection as a new research area. This article highlights that these bioactive molecules are now being incorporated into our overall understanding of nutrient needs for healthy infant development, preparing each individual infant to succeed as a healthy and protected adult throughout its life. In essence, miRNAs are a new language in the Rosetta stone of health that is mammalian lactation.

Preterm birth alters the development of cortical microstructure and morphology at term-equivalent age

IntroductionThe dynamic nature and complexity of the cellular events that take place during the last trimester of pregnancy make the developing cortex particularly vulnerable to perturbations. Abrupt interruption to normal gestation can lead to significant deviations to many of these processes, resulting in atypical trajectory of cortical maturation in preterm birth survivors. MethodsWe sought to first map typical cortical micro- and macrostructure development using invivo MRI in a large sample of healthy term-born infants scanned after birth (n = 259). Then we offer a comprehensive characterization of the cortical consequences of preterm birth in 76 preterm infants scanned at term-equivalent age (37–44 weeks postmenstrual age). We describe the group-average atypicality, the heterogeneity across individual preterm infants, and relate individual deviations from normative development to age at birth and neurodevelopment at 18 months. ResultsIn the term-born neonatal brain, we observed heterogeneous and regionally specific associations between age at scan and measures of cortical morphology and microstructure, including rapid surface expansion, greater cortical thickness, lower cortical anisotropy and higher neurite orientation dispersion. By term-equivalent age, preterm infants had on average increased cortical tissue water content and reduced neurite density index in the posterior parts of the cortex, and greater cortical thickness anteriorly compared to term-born infants. While individual preterm infants were more likely to show extreme deviations (over 3.1 standard deviations) from normative cortical maturation compared to term-born infants, these extreme deviations were highly variable and showed very little spatial overlap between individuals. Measures of regional cortical development were associated with age at birth, but not with neurodevelopment at 18 months. ConclusionWe showed that preterm birth alters cortical micro- and macrostructural maturation near the time of full-term birth. Deviations from normative development were highly variable between individual preterm infants.

Neural Speech Encoding in Infancy Predicts Future Language and Communication Difficulties.

Purpose This study aimed to construct an objective and cost-effective prognostic tool to forecast the future language and communication abilities of individual infants. Method Speech-evoked electroencephalography (EEG) data were collected from 118 infants during the first year of life during the exposure to speech stimuli that differed principally in fundamental frequency. Language and communication outcomes, namely four subtests of the MacArthur-Bates Communicative Development Inventories (MCDI)-Chinese version, were collected between 3 and 16 months after initial EEG testing. In the two-way classification, children were classified into those with future MCDI scores below the 25th percentile for their age group and those above the same percentile, while the three-way classification classified them into < 25th, 25th-75th, and > 75th percentile groups. Machine learning (support vector machine classification) with cross validation was used for model construction. Statistical significance was assessed. Results Across the four MCDI measures of early gestures, later gestures, vocabulary comprehension, and vocabulary production, the areas under the receiver-operating characteristic curve of the predictive models were respectively .92 ± .031, .91 ± .028, .90 ± .035, and .89 ± .039 for the two-way classification, and .88 ± .041, .89 ± .033, .85 ± .047, and .85 ± .050 for the three-way classification (p < .01 for all models). Conclusions Future language and communication variability can be predicted by an objective EEG method that indicates the function of the auditory neural pathway foundational to spoken language development, with precision sufficient for individual predictions. Longer-term research is needed to assess predictability of categorical diagnostic status. Supplemental Material https://doi.org/10.23641/asha.15138546.

The Babytwins Study Sweden (BATSS): A Multi-Method Infant Twin Study of Genetic and Environmental Factors Influencing Infant Brain and Behavioral Development.

Twin studies can help us understand the relative contributions of genes and environment to phenotypic trait variation, including attentional and brain activation measures. In terms of applying methodologies such as electroencephalography (EEG) and eye tracking, which are key methods in developmental neuroscience, infant twin studies are almost nonexistent. Here, we describe the Babytwins Study Sweden (BATSS), a multi-method longitudinal twin study of 177 MZ and 134 DZ twin pairs (i.e., 622 individual infants) covering the 5-36 month time period. The study includes EEG, eye tracking and genetics, together with more traditional measures based on in-person testing, direct observation and questionnaires. The results show that interest in participation in research among twin parents is high, despite the comprehensive protocol. DNA analysis from saliva samples was possible in virtually all participants, allowing for both zygosity confirmation and polygenic score analyses. Combining a longitudinal twin design with advanced technologies in developmental cognitive neuroscience and genomics, BATSS represents a new approach in infancy research, which we hope to have impact across multiple disciplines in the coming years.

Apgar score at 10 minutes and adverse outcomes among low-risk pregnancies

Objective Among low-risk pregnancies, we ascertained the association between 10-minute Apgar score and adverse outcomes of newborn infants. Method We conducted a retrospective cohort study using the U.S. vital statistics datasets (2011–2018), which included live births from low-risk women with non-anomalous singleton gestations who delivered at 37–41 weeks. When a newborn infant had an abnormal 5-minute Apgar score (0–5), a 10-minute Apgar score was documented in the birth certificate. Apgar score at 10 min was categorized as low (0–3), moderate (4–6), and normal (7–10). The primary outcome was composite neonatal adverse outcome. The secondary outcomes were individual neonatal adverse outcomes and infant mortality. Multivariable Poisson regression analyses were used to estimate the association between 10-minute Apgar score and adverse outcomes (using adjusted relative risk [aRR] and 95% confidence intervals [CI]). Results Of 31.5 million live births delivered (2011–2018), 111,163 (0.4%) met inclusion criteria; of them, 74.2%, 20.7%, and 5.1% had normal, moderate, and low 10-minute Apgar scores, respectively. The overall composite neonatal adverse outcome was 100.6 per 1,000 live births and the risk was significantly higher among those with a moderate (aRR 3.19; 95% CI 3.06–3.31) or low 10-minute Apgar score (aRR 6.62; 95% CI 6.34–6.91) than with a normal 10-minute Apgar score. Infant mortality also showed a similar pattern. Newborn infants with improved Apgar scores from 5 to 10 min were associated with lower risks of the composite neonatal adverse outcome, as well as infant mortality, than those with scores that remained stable. Conclusion Among low-risk pregnancies, newborn infants with a lower 10-minute Apgar score were associated with a higher risk of adverse outcomes.

Measurement of Force Applied by Infant Tongue to Three Types of Artificial Nipple: Investigation of Dynamic Actions in Relation to the Shape and Size of the Artificial Nipple

This study aims to elucidate whether the force applied by an infant's tongue differs or not depending on geometrical differences in the artificial nipples. We developed three sensorized artificial nipple devices using six small force sensors and we have measured the tongue force during sucking in 11 infants. As a result, we have showed that the order of sensor responses and sucking period are similar among different geometries of artificial nipples. However, we have also observed that the maximum force measured differed in different artificial nipples. Furthermore, we have also observed differences in the estimated velocity the tongue movement between individual infants. Overall, this study showed that it is feasible to measure the dynamic properties of artificial nipples toward the definition of clear recommendations for mothers that wish to select the appropriate artificial nipple for their babies on an individual basis. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.