New Study on Kynurenic Acid in Mammalian Milks

This interesting new study from Poland on kynurenic acid (KYNA) in mammalian milks found a possible role for KYNA as an anti-obesogen by influencing metabolism and weight gain. Researchers found higher levels of KYNA in human milk versus markedly lower levels in artificial infant milks. "In the context of lifelong obesity observed worldwide in children fed artificially, our results imply that insufficient amount of KYNA in baby formulas could be considered as one of the factors associated with increased mass gain."

Title: Kynurenic acid as the neglected ingredient of commercial baby formulas.

In: Scientific Reports 2019 Apr 15;9(1):6108. doi: 10.1038/s41598-019-42646-4.

Authors: Milart P, Paluszkiewicz P, Dobrowolski P, Tomaszewska E, Smolinska K, Debinska I, Gawel K, Walczak K, Bednarski J, Turska M, Raban M, Kocki T, Turski WA.

Abstract: "The global increase in resorting to artificial nutritional formulas replacing breastfeeding has been identified among the complex causes of the obesity epidemic in infants and children. One of the factors recently recognized to influence metabolism and weight gain is kynurenic acid (KYNA), an agonist of G protein-coupled receptor (GPR35). Therefore the aim of the study was to determine the concentration of KYNA in artificial nutritional formulas in comparison with its level in human breast milk and to evaluate developmental changes in rats exposed to KYNA enriched diet during the time of breastfeeding. KYNA levels were measured in milk samples from 25 healthy breast-feeding women during the first six months after labor and were compared with 21 time-adjusted nutritional formulas. Animal experiments were performed on male Wistar rats. KYNA was administered in drinking water. The content of KYNA in human milk increases more than 13 times during the time of breastfeeding while its level is significantly lower in artificial formulas. KYNA was detected in breast milk of rats and it was found that the supplementation of rat maternal diet with KYNA in drinking water results in its increase in maternal milk. By means of the immunoblotting technique, GPR35 was evidenced in the mucosa of the jejunum of 1-day-old rats and distinct morphological changes in the jejunum of 21-day-old rats fed by mothers exposed to water supplemented with KYNA were found. A significant reduction of body weight gain of rats postnatally exposed to KYNA supplementation without changes in total body surface and bone mineral density was observed. The rat offspring fed with breast milk with artificially enhanced KYNA content demonstrated a lower mass gain during the first 21 days of life, which indicates that KYNA may act as an anti-obesogen. Further studies are, therefore, warranted to investigate the mechanisms regulating KYNA secretion via breast milk, as well as the influence of breast milk KYNA on mass gain. In the context of lifelong obesity observed worldwide in children fed artificially, our results imply that insufficient amount of KYNA in baby formulas could be considered as one of the factors associated with increased mass gain."

Open access:

New Study on the Milk Biome in Expressed Milk vs. Milk Via Direct Breastfeeding

From the press release:

“'We found that milk bacteria are different in mothers who pump their milk,'” said Dr. Meghan Azad, the University of Manitoba investigator who led the study. “'We suspect that pumping may prevent the transfer of oral bacteria from the infant to the mother and might introduce other bacteria from the pump. Therefore, contrary or in addition to the hypothesis that milk bacteria come from the mother’s gut, our results suggest that the infant’s oral bacteria are important in shaping the milk microbiota.'"

Title: Composition and Variation of the Human Milk Microbiota Are Influenced by Maternal and Early-Life Factors.

Authors: Moossavi S, Sepehri S, Robertson B, Bode L, Goruk S, Field CJ, Lix LM, de Souza RJ, Becker AB, Mandhane PJ, Turvey SE, Subbarao P, Moraes TJ, Lefebvre DL, Sears MR, Khafipour E, Azad MB.

In: Cell Host & Microbe 2019 Feb 13;25(2):324-335.e4. doi: 10.1016/j.chom.2019.01.011.

Press release:

Summary with references:

Summary: "Breastmilk contains a complex community of bacteria that may help seed the infant gut microbiota. The composition and determinants of milk microbiota are poorly understood. Among 393 mother-infant dyads from the CHILD cohort, we found that milk microbiota at 3-4 months postpartum was dominated by inversely correlated Proteobacteria and Firmicutes, and exhibited discrete compositional patterns. Milk microbiota composition and diversity were associated with maternal factors (BMI, parity, and mode of delivery), breastfeeding practices, and other milk components in a sex-specific manner. Causal modeling identified mode of breastfeeding as a key determinant of milk microbiota composition. Specifically, providing pumped breastmilk was consistently associated with multiple microbiota parameters including enrichment of potential pathogens and depletion of bifidobacteria. Further, these data support the retrograde inoculation hypothesis, whereby the infant oral cavity impacts the milk microbiota. Collectively, these results identify features and determinants of human milk microbiota composition, with potential implications for infant health and development.”

Some New Studies

Title: Identification of Differentiating Metabolic Pathways between Infant Gut Microbiome Populations Reveals Depletion of Function-Level Adaptation to Human Milk in the Finnish Population.

In: mSphere 2019 Mar 20;4(2). pii: e00152-19. doi: 10.1128/mSphereDirect.00152-19.

Authors: Majta J, Odrzywolek K, Milanovic B, Hubar V, Wrobel S, Strycharz-Angrecka E, Wojciechowski S, Milanowska K.

Open access:

Title: Relationship of Necrotizing Enterocolitis Rates to Adoption of Prevention Practices in US Neonatal Intensive Care Units.

In: Advances in Neonatal Care 2019 Mar 19. doi: 10.1097/ANC.0000000000000592. [Epub ahead of print]

Authors: Gephart SM, Quinn MC.


Title: A Pilot Study of Oxytocin in Low-Income Women With a Low Birth-Weight Infant: Is Oxytocin Related to Posttraumatic Stress?

In: Advances in Neonatal Care 2019 Mar 19. doi: 10.1097/ANC.0000000000000601. [Epub ahead of print]

Authors: Garfield L, Holditch-Davis D, Carter CS, McFarlin BL, Seng JS, Giurgescu C, White-Traut R.


Title: Determination of four parabens and bisphenols A, F and S in human breast milk using QuEChERS and liquid chromatography coupled to mass spectrometry.

In: Journal of Chromatography B, Analytical Technologies in the Biomedical and Life Sciences 2019 Mar 7. pii: S1570-0232(18)31845-2. doi: 10.1016/j.jchromb.2019.03.004. [Epub ahead of print]

Authors: Dualde P, Pardo O, F Fernández S, Pastor A, Yusà V.


Quote of the Day

The following quote from neurophysiologist Mark Hallett reinforces the recommendation in Step 9 from the World Health Organization (WHO) and UNICEF’s Ten Steps to Successful Breastfeeding, which infers that learning infant breastfeeding skills is dependent upon practice that is specific to the task (The Specificity Principle). The Ten Steps are one aspect of the Baby Friendly Hospital Initiative, and from 1986 to early 2018, Step 9 advised to “Give no artificial nipples to breastfeeding infants.” The language of the Ten Steps was revised in 2018, and the current language of Step 9 states, “Counsel mothers on the use and risks of feeding bottles, teats and pacifiers.”

Quote of the Day from Mark Hallett, M.D.:

Immediately after learning, the motor memory is fragile. In particular, it is vulnerable to disruption by learning of something similar.  However, if there is no disruption, with the passage of time, the memory becomes more robust. It is this process, of becoming more and more robust with time, that is designated consolidation.

In: Hallett M (2006).  The role of the motor cortex in motor learning.  In Motor Control and Learning (Latash ML & Lestienne F, Eds.), p. 92.  New York: Springer.

Dr. Hallett developed and has maintained the Human Motor Control Section (HMCS) at the National Institutes of Health in Bethesda, Maryland.

Hallett’s faculty profile:   

Article: “Celebrating Mark Hallett’s 30 Years of Research”:

Dr. Hallett’s interview from NIH’s Oral History Program:

Quote of the Day

When a baby has not yet learned or re-learned the oral grasp of the nipple-areolar complex, a primary and critical recommendation from the clinician is skin-to-skin contact ad lib between members of the dyad. As an IBCLC, I especially appreciate these passages from Saffran & Kirkham on the visual environment, spatial learning, and the impact of anticipatory behavior:

“Learning itself is affected by complexity . . . . infants were as capable in the visual domain as in the auditory domain . . . . However, an important aspect of the ability to perceive the visual environment as coherent and intelligible is understanding objects’ spatial locations and what their present locations might predict about future events. Acquisition of this type of knowledge is essential for motion perception and for the production of action sequences; one has to learn not only which actions are appropriate, but also where and when they should be performed. For example, if, while looking out the window of your house, you see the child walking up the path to the front door, you can reasonably predict that you will see her next in the doorway of your house. You can use this information to guide appropriate anticipatory behavior, such as moving to a location that provides a view of the door to greet your child as she comes inside. In other words, each visual event is temporally related both to the previous event and to the future event and occurs within a spatial context.”

Authors: Jenny R. Saffran and Natasha Z. Kirkham

Journal (review) article title: Infant Statistical Learning.

In: Annual Reviews of Psychology 2018 January 04;69:181-203. DOI: 10.1146/annurev-psych-122216-011805

Full text:

In Celebration of the IBCLC

In honor of IBCLCs around the world, and in celebration of IBCLC Day on this date:

The work of the IBCLC is always interesting. Sometimes our work is straightforward and uncomplicated, and we often provide our clinical skills in support of complex feeding situations. These feeding challenges range from mild in complexity to highly complex.

Kudos to IBCLCs everywhere, and to all others who support dyads and their families in infant feeding toward optimal health!

New Study: Sex-Specific Cardiac Benefits from Human Milk

This interesting new open access study found sex-specific benefits from human milk in regard to cardiac health.

Title: Content of n-3 LC-PUFA in Breast Milk Four Months Postpartum is Associated with Infancy Blood Pressure in Boys and Infancy Blood Lipid Profile in Girls.

In: Nutrients 2019, 11(2), 235;

Authors: Signe Bruun, Lenie van Rossem, Lotte Lauritzen, Steffen Husby, Lotte Neergaard Jacobsen, Kim F. Michaelsen, Maria Boysen Sandberg, Ken D. Stark, Jan Sørensen and Gitte Zachariassen.

From the abstract: "Based on 336 mother-child dyads, high n-3 LC-PUFA in breast milk was inversely associated with systolic and diastolic BP in boys at 4 months (β = −20.0 (95% CI = −33.4, −6.7), p = 0.004 and β = −10.2 (95% CI = −19.8, −0.5), p = 0.039, respectively); inversely associated with HDL cholesterol, and directly associated with triglyceride in girls at 4 months (β = −0.7 (95% CI = −1.1, −0.3), p = 0.001 and β = 3.1 (95% CI = 1.0, 5.2), p = 0.005, respectively) . . . . Our results indicate that early intake of n-3 LC-PUFA can affect early development in cardiometabolic factors such as BP and BLP in a sex-specific manner."

On Skin-to-Skin Contact, Associative Learning, and Reward-Based Learning

Across the lifespan, the learning of all feeding and drinking skills reflects procedural learning, reinforcement learning, reward-based learning, and associative learning. During associative learning, we learn to predict relationships, such as between two or more stimuli, a stimulus and a response, and between a response and its consequence.

For young newborns, learning milk-feeding skills is supported and hastened by the primitive survival reflexes, pre-adapted movements that are further adapted during sensory-perceptual-motor learning. The crawl reflex enables us to “drive” to nature’s first restaurant, and the rooting reflex further orients us to the dining location. As the infant determines the action (action planning) of moving still closer toward the nipple-areolar complex, a reflexive lunge is displayed by the infant toward the breast, in tandem with a reflexive wide open gape, with the tongue extended over the lower alveolar ridge. When the baby learns how to achieve and sustain the oral grasp, the suck reflex is soon stimulated. In mutuality and reciprocity between both members of the dyad, milk is released via the initial Milk Ejection Reflex (MER) as well as subsequent MERs in the same meal, much like service at a fine dining establishment, as one course at a time is served. Should the flow of milk temporarily overwhelm the young novice, the cough reflex helps us to reorganize our swallowing movements. With the repetition of practice, the baby’s suck reflex becomes increasingly more coordinated with the swallow reflex, in support of increasing motor control for the infant’s effective transfer of milk.

However, the remarkable presence of the primitive survival reflexes does not guarantee the oral grasp and effective sucking for all infant milk-feeding methods all the time. Following a learning experience with an artificial nipple and the subsequent return to the breast, skill decay (decreased speed and accuracy) is often observed for the baby’s oral grasp/latch at the breast, and/or effective sucking for adequate milk transfer, reflecting the cognitive demands of task-switching. These cognitive demands are particularly pronounced during early learning when memories are in their most fragile state, and furthermore, the younger we are, the greater the cognitive demands of task-switching.

When clinicians are called upon to assist the infant in a transfer of learning from artificial nipple to the breast, finger-feeding is often a highly effective technique in helping the infant learn to associate the smell, touch, and taste of the mother or other caregiver’s skin with sucking and receiving milk. In the language of the cognitive sciences, this pairing of associates is critical for learning and re-learning. However, the very first clinical recommendation is often skin-to-skin contact ad lib, also to familiarize the infant with that rich sensory milieu, including the visual field of that feeding location.

Susan Ludington, RN CNM PhD FAAN is the Executive Director of the United States Institute for Kangaroo Care (USIKC). Ludington has been studying skin-to-skin contact via Kangaroo Care since 1988, and offers this extensive annotated bibliography and reference list on the USIKC website.

Associative learning is heavily studied in the cognitive sciences, as is reward-based learning, reinforcement learning, and procedural learning. Some recent studies:

Title: Pavlovian reward learning elicits attentional capture by reward-associated stimuli.

Authors: Mine C, Saiki J.

In: Attention, Perception & Psychophysics 2018 Jul;80(5):1083-1095. doi: 10.3758/s13414-018-1502-2.

Title: I like it by mere association: Conditioning preferences in infants.

Authors: Jenny L Richmond, Jenna Zhao, Gabrielle Weidenmann.

In: Journal of Experimental Child Psychology 2017 September;161:19-31. doi: 10.1016/j.jecp.2017.03.015.

A new meta-analysis on associative word learning and task-switching in infancy:

Title: Associative word learning in infancy: A meta-analysis of the switch task.

Authors: Tsui ASM, Byers-Heinlein K, Fennell CT.

In: Developmental Psychology 2019 Feb 7. doi: 10.1037/dev0000699.

And one more: These authors reviewed neuroimaging studies of cognitive flexibility, with emphasis on set shifting and task switching. 

Title: Demystifying cognitive flexibility: Implications for clinical and developmental neuroscience.

Authors: Dajani DR, Uddin LQ.

In: Trends in Neurosciences 2015 Sep;38(9):571-8. doi: 10.1016/j.tins.2015.07.003.

Full text/author manuscript:

New Human Milk Studies

From Turkey:

Title: Probiotic characteristics of bacteriocin-producing Enterococcus faecium strains isolated from human milk and colostrum.

Authors: Bagci U, Ozmen Togay S, Temiz A, Ay M.

In: Folia Microbiologica (Praha) 2019 Feb 9. doi: 10.1007/s12223-019-00687-2. [Epub ahead of print]

Abstract with references:

From Spain:

Title: Concentrations of dioxins and furans in breast milk of women living near a hazardous waste incinerator in Catalonia, Spain.

Authors: Schuhmacher M, Mari M, Nadal M, Domingo JL.

In: Environment International 2019 Feb 7;125:334-341. doi: 10.1016/j.envint.2019.01.074. [Epub ahead of print]

Open access:

From Germany:

Title: New short-term heat inactivation method of cytomegalovirus (CMV) in breast milk: impact on CMV inactivation, CMV antibodies and enzyme activities.

Authors: Jens Maschmann, Denise Müller, Katrin Lazar, Rangmar Goelz, Klaus Hamprecht.

In: Archives of Disease in Childhood. Fetal and Neonatal Edition. 2019 Feb 6. pii: fetalneonatal-2018-316117. doi: 10.1136/archdischild-2018-316117. [Epub ahead of print]


A New Method for Studying Thousands of Human Milk Peptides

Researchers from The Netherlands have utilized an efficient method for studying the peptidome in human milk, allowing them to perform "qualitative and quantitative detection of about 4000 endogenous human milk peptides in a total analysis time of just 18 hours".

Study Title: Toward an efficient workflow for the analysis of the human milk peptidome.

Authors: Dingess KA, van den Toorn HWP, Mank M, Stahl B, Heck AJR.

In: Analytical and Bioanalytical Chemistry  2019 February 2. doi: 10.1007/s00216-018-01566-4.

Full text:

On Sleep and Learning

We clinicians often observe youngest newborns who display improved skill (greater speed and accuracy) for the oral grasp and nutritive suckling after a short nap between breasts and after a longer stretch of sleep. Consolidation is a term from the cognitive sciences that refers to the building of memory, including motor memory, into a robust state. Sleep is a critical aspect of memory consolidation. 

As babies become progressively more skilled in milk-feeding, increasingly less sleep is required by the infant. Although sleep is critical in building robust memory, interference in learning can impede memory consolidation, in spite of adequate sleep. In their 1995 paper providing the first formal definition on nipple confusion, authors Mary Ann Neifert, Ruth Lawrence, and Joy Seacat discussed interference as a factor in breastfeeding difficulties that often follow an infant's learning experience with an artificial nipple. 

This fascinating new study from Switzerland was done on adults, looking at whole-night rocking and its impact on sleep and memory. Does frequent rocking also benefit preterm infants, as well as babies in general? There is often an intrinsic need to rock one's infant, and to stand and sway back and forth with the little one. 

Title: Whole-Night Continuous Rocking Entrains Spontaneous Neural Oscillations with Benefits for Sleep and Memory.

In: Current Biology 2019 Jan 11. pii: S0960-9822(18)31662-2. doi: 10.1016/j.cub.2018.12.028. [Epub ahead of print]

Study Authors: Perrault AA, Khani A, Quairiaux C, Kompotis K, Franken P, Muhlethaler M, Schwartz S, Bayer L.

The following 1989 study associated rocking of preterm infants with improved neuromuscular development.

Title: Effects of rocking on neuromuscular development in the premature.

Authors: Clark DL, Cordero L, Goss KC, Manos D.

In: Biology of the Neonate 1989;56(6):306-314.

In Celebration of Carolyn Rovee-Collier (1942 - 2014)

The following treasure of a short YouTube video is of the late Carolyn Rovee-Collier (1942 - 2014), a developmental psychologist who mastered a steep uphill climb in her field.

Early in her career, a powerful but mistaken dogma held that babies could not learn until later in their first year. In that era, behavior in younger infants was perceived as stimulus and response but without actual learning taking place.

Dr. Rovee-Collier authored over 200 papers during her career, although three years transpired before her first paper was accepted for publication on aspects of infant long-term memory. By persevering in the face of much opposition in what was then a male-dominated field, Rovee-Collier succeeded in dismantling the old paradigm.

In 2006, Peter Gerhardstein interviewed Rovee-Collier for The Society of Research in Child Development, who has since made her 30-page oral history available online - another treasure.

After her passing in 2014, The New York Times, The Boston Globe, and other news outlets published her obituary, and moving tributes to Rovee-Collier are also found in various professional publications.

Rovee-Collier's insightful master's thesis was on sucking in puppies.

The 30-page Carolyn Rovee-Collier oral history:…/d…/rovee-collier_carolyn_interview.pdf

A short video showing Rovee-Collier in her preferred lab, i.e., visiting babies in their own home environments:

BabyLabs, Cognitive Flexibility, and IBCLCs

Researchers study how babies learn in infant cognition labs around the world, often in graduate programs in developmental psychology. The following link is to the home page of one such lab, located at the University of Essex, a public research university in Essex, England. At the bottom of their home page, a copy of their tweet from November 29, 2018 asks, "Help inform our research by filling out this online survey on #eating behavior and #food preference in childhood @EssexBabylab".

Will this lab and other BabyLabs someday study the sensory-perceptual-motor learning of infant milk-feeding skills with one or more skilled IBCLCs included on their research team? Also important to study is the observable skill decay (motor forgetting) for infant breastfeeding skills that often follows the use of an artificial nipple, particularly during early learning but not only during early learning. The re-acquisition of infant breastfeeding skills is another important aspect for future study. There is already a body of work on the study of infant sucking behaviors in puppies, including the work of the Carolyn Rovee-Collier (1942-2014), a developmental psychologist who is considered the founder of the field of infant long-term memory research. Rovee-Collier completed her insightful master’s thesis on sucking in puppies.

Early memories are fragile, including motor memories, and we commonly face early challenges in learning and remembering a new computer password or a new telephone number. Our human need for task-specific practice is reflected in The Specificity Principle, and the repetition of this task-specific practice is necessary for gradually building robust memory for each of those numerical sequences for our motor performance, as well as our gradual ability to visually identify a particular telephone number, and to correctly state a specific numerical sequence aloud. Another important precept from kinesiology: the greater the difficulty of the task, the greater the need for practice that is specific for the task.

When a new music student begins once-a-week music lessons but does not practice the new music that was awkwardly learned in the last lesson, it is no surprise that little to none of the previous music lesson is recalled at the next lesson. However, when the student becomes motivated enough to engage in the repetition of task-specific practice, and when the student is given appropriate verbal, visual, and manual guidance from the instructor, the voluntary process of task-specific practice is an effective opportunity for building increasingly greater motor control for the task.

The cognitive demands of task switching have been heavily studied for decades, including the well-known switch costs of decreased speed and accuracy for the task. Today’s PubMed search using the term “task switching” yielded 3,185 results. Note that when the search term is hyphenated as “task-switching”, the yield is far fewer at 1,461 results. PubMed searches can be highly specific, even in regard to something as small as the presence or absence of a hyphen!

In helping babies to learn or relearn the oral grasp at the breast following a learning experience with an artificial nipple, finger-feeding is often highly effective, particularly in younger infants. This is reflected in the well-known precept from developmental science termed the exuberant learning of infancy, and the younger the baby, the faster the learning. Forgetting is also rapid in infancy, and thus the frequent observations of skill decay (motor forgetting) for infant breastfeeding skills that often follow one or more learning experiences with an artificial nipple, particularly during early learning but not only during early learning.

In the new review article linked below, the value of associative learning mechanisms is discussed. In the field of infant feeding, finger-feeding provides babies the opportunity to learn to associate the sensory-perceptual-motor learning experience of human touch with sucking and receiving the reward of milk for one’s efforts, also reflecting reward-based learning and reinforcement learning. Infant feeding clinicians such as IBCLCs often observe a heavier weighting of the primitive survival reflexes toward the more recently learned feeding method, and thus task-switching for infant milk-feeding skills is frequently observed to be a challenging experience, particularly during early learning when memories are notably fragile. Similarly, bottle-fed infants often display difficulty with the oral grasp of a new artificial nipple that is different from the previously learned style of artificial nipple, and these difficulties range from mild to moderate to pronounced.

Cognitive flexibility also has a developmental sequence. In infancy, we have the least ability for skillfully switching between tasks, yet as we reach childhood, we display more cognitive flexibility than our younger baby selves. By adolescence, we have achieved even greater cognitive flexibility, and by adulthood, we have reached the pinnacle of cognitive flexibility, yet discerning and differentiating between things that are similar yet different is often cognitively demanding for adults who are otherwise skilled in many areas. Some of us who have first learned to use western utensils may opt to later learn how to use chopsticks, but many of us find that learning to use chopsticks is too confusing, i.e., it is too cognitively demanding, and we may avoid the cognitive demands of any further practice in the use of chopsticks. Others will enjoy the cognitive challenges of learning how to use chopsticks, and will continue the trial-and-error process toward increasingly greater skill over time. (The trajectory is the same for the hand-to-mouth movements involved in using a spoon, fork, and chopsticks, but the learning curve is steep for the novel manual grasp of chopsticks).

The following new review article, “Getting a Grip on Cognitive Flexibility”, is authored by Senne Braem of Ghent University in Belgium and Tobias Egner of Duke University in the U.S.

From their abstract: “Cognitive flexibility refers to the ability to quickly reconfigure our mind, like when we switch between different tasks. This review highlights recent evidence showing that cognitive flexibility can be conditioned by simple incentives typically known to drive lower-level learning, such as stimulus-response associations. Cognitive flexibility can also become associated with, and triggered by, bottom-up contextual cues in our environment, including subliminal cues. Therefore, we suggest that the control functions that mediate cognitive flexibility are grounded in, and guided by, basic associative learning mechanisms, and abide by the same learning principles as more low-level forms of behavior. Such a learning perspective on cognitive flexibility offers new directions and important implications for further research, theory, and applications.”

For more information on the acquisition and re-acquisition of infant breastfeeding skills, please join us for our 3-hour intensive webinar,

MoreThanReflexes: Learning, Forgetting, and Relearning Infant Breastfeeding Skills.

Motor Learning Terms of the Day

motor forgetting Skill decay, or decreased speed and accuracy for the task.

interference theory A theory that forgetting is caused by interference from other learned information/experiences.

Two major theories on forgetting, including motor forgetting or skill decay, are:

  • trace decay (decay of the memory trace) due to lack of practice, whether this lack of practice takes place in good health or due to illness or injury, and

  • trace decay subsequent to an interference effect

A memory trace is a group of neurons, interconnected and encoded for specific memories, including motor memories.

In the 1995 paper by Neifert, Lawrence, and Seacat, “Nipple Confusion: Toward a Formal Definition”, the authors discuss interference as a factor in observable breastfeeding difficulties that often follow an infant’s learning experience with an artificial nipple.

For an intensive discussion on motor learning and motor forgetting (skill decay) within the context of the primitive survival reflexes, please join us for our dynamic webinar,

More Than Reflexes: Learning, Forgetting and Relearning Infant Breastfeeding Skills

Three New Studies on Duration

From Sweden:

Open Access

Title: Breastfeeding and risk for ceasing in mothers of preterm infants—Long‐term follow‐up.

In: Maternal & Child Nutrition 2018 Oct; 14(4): e12618. doi: 10.1111/mcn.12618

Authors: Jenny Ericson, Mats Eriksson, Pat Hoddinott, Lena Hellström-Westas, Renée Flacking.

From the abstract:


“Exclusive breastfeeding at discharge, higher maternal educational level, and shorter length of stay in the neonatal intensive care unit were factors associated with higher breastfeeding prevalence during the preterm infants' first year of life.

The results give insights on long‐term outcomes of breastfeeding in mothers who breastfed their preterm infants at discharge from the neonatal intensive care unit, where 64% of the infants were breastfed at 6 months.

Most infants were fed breast milk directly at the breast; few infants received expressed breast milk by bottle, tube, or cup.”

From Denmark:

Open Access

Title: The role of intention and self-efficacy on the association between breastfeeding of first and second child, a Danish cohort study.

In: BMC Pregnancy and Childbirth (BioMed Central Pregnancy and Childbirth) 2018 Nov 22;18(1):454. doi: 10.1186/s12884-018-2086-5.

Authors: Kronborg H, Foverskov E, Væth M, Mainburg RD.

From the abstract:

“BACKGROUND: The impact of parity on breastfeeding duration may be explained by physiological as well as psychosocial factors. The aim in the present study was to investigate the mediating influence of intention and self-efficacy on the association between the breastfeeding duration of the first and the following child. CONCLUSION: Due to a reinforcing effect of intention and self-efficacy, breastfeeding support should focus on helping the first time mothers to succeed as well as to identify the second time mother with low self-efficacy and additional need for support.”

From Iran:

Open Access

Title: The Association between Household Socioeconomic Status, Breastfeeding, and Infants' Anthropometric Indices.

In: International Journal of Preventive Medicine 2018 Oct 12;9:89. doi: 10.4103/ijpvm.IJPVM_52_17. eCollection 2018.

Authors: Ajami M, Abdollahi M, Salehi F, Oldewage-Theron W, Jamshidi-Naeini Y.

From the abstract:

“BACKGROUND: The growth, learning, and contribution to active life in the communities are better in well-nourished children, and various factors influence infants' feeding. In this study, we assessed whether household socioeconomic status (SES) affects infants' length-for-age, weight-for-age (indicators of health and nutritional status) and breastfeeding (BF) (a necessity for optimal growth and health) status. CONCLUSIONS: Nutritional status, duration of BF, and EBF might be determined by household SES and maternal education. Therefore, these findings can be used to decide how to focus on appropriate target groups in family education planning to improve children's development to its most possible.”

Three New Studies

From Germany:

Open access

Title: Intranasal breast milk for premature infants with severe intraventricular hemorrhage - an observation.

In: European Journal of Pediatrics 2018 Nov 1. doi: 10.1007/s00431-018-3279-7.

Authors: Keller T, Körber F, Oberthuer A, Schafmeyer L, Mehler K, Kuhr K, Kribs A.

Abstract: "For nasal application of neurotrophins and mesenchymal stem cells, successful delivery to the brain and therapeutic effects are known from experimental data in animals. Human breast milk contains neurotrophins and stem cells, but gavage tube feeding in preterm infants bypasses the naso-oropharynx. This is a first exploration on additional nasal breast milk and neuromorphological outcome after severe neonatal brain injury. We present a retrospective summary of 31 very low birth weight preterm infants with intraventricular hemorrhage °3/4 from one third-level neonatal center. All were breast milk fed. Sixteen infants additionally received nasal drops of fresh breast milk daily with informed parental consent for at least 28 days. Cerebral ultrasound courses were reviewed by a pediatric radiologist blinded to the intervention. The main outcome measure was severity of porencephalic defects before discharge. Clinical covariates were comparable in both groups. With nasal breast milk, a trend to a lower incidence for severe porencephalic defects (21% vs. 58%) was detected. Incidences were lower for progressive ventricular dilatation (71% vs. 91%) and surgery for posthemorrhagic hydrocephalus (50% vs. 67%). Conclusion: The hypothesis is generated that early intranasal application of breast milk could have a beneficial effect on neurodevelopment in preterm infants. Controlled investigation is needed. What is Known: • Successful delivery to the brain and therapeutic effects are known for nasal application of neurotrophins and mesenchymal stem cells from experimental data in animal studies. • Human breast milk contains neurotrophins and stem cells, but gavage tube feeding in preterm infants bypasses the naso-oropharynx. What is New: • This is the first report on additional nasal breast milk application in very low birth weight preterm infants with severe brain injury observing a trend for less severe porencephalic defects. • The hypothesis is generated that nasal breast milk might exert neuroprotective effects in preterm infants."

From The Netherlands:

Title: Relationship between socioeconomic status and weight gain during infancy: The BeeBOFT study.

In: PLoS One. 2018 Nov 2;13(11):e0205734. doi: 10.1371/journal.pone.0205734. eCollection 2018.

Authors: Wang L, van Grieken A, Yang-Huang J, Vlasblom E, L'Hoir MP, Boere-Boonekamp MM, Raat H.

Abstract: "BACKGROUND: Increased weight gain during infancy is a risk factor for obesity and related diseases in later life. The aim of the present study was to investigate the association between socioeconomic status (SES) and weight gain during infancy, and to identify the factors mediating the association between SES and infant weight gain. METHODS: Subjects were 2513 parent-child dyads participating in a cluster randomized controlled intervention study. Family SES was indexed by maternal education level. Weight gain in different time windows (infant age 0-3, 0-6, and 6-12 months) was calculated by subtracting the weight for age z-score (WAZ) between the two time-points. Path analysis was performed to examine the mediating pathways linking SES and infant weight gain. RESULTS: On average, infants of low-educated mothers had a lower birth weight and caught-up at approximately 6 months. In the period of 0-6 months, infants with low-educated mothers had an 0.42 (95% CI 0.27-0.57) higher gain in weight for age z-score compared to children with high-educated mothers. The association between maternal education level and increased infant weight gain in the period of 0-6 months can be explained by infant birth weight, gestational age at child birth, duration of breastfeeding, and age at introduction of complementary foods. After adjusting all the mediating factors, there was no association between maternal education level and infant weight gain. CONCLUSION: Infants with lower SES had an increased weight gain during the first 6 months of infancy, and the effect can be explained by infant birth weight, gestational age at child birth, and infant feeding practices.”

From China:

Open access

Title: A Short Message Service Intervention for Improving Infant Feeding Practices in Shanghai, China: Planning, Implementation, and Process Evaluation.

In: JMIR Mhealth Uhealth 2018 Oct 29;6(10):e11039. doi: 10.2196/11039.

Authors: Jiang H, Li M, Wen L, Baur LA, He G, Ma X, Qian X.

Abstract: "BACKGROUND: Although mobile health (mHealth) has been widely applied in health care services, few studies have reported the detailed process of the development and implementation of text messaging (short message service, SMS) interventions. OBJECTIVE: Our study aims to demonstrate the process and lessons learned from a community-based text messaging (SMS) intervention for improving infant feeding in Shanghai, China. METHODS: The intervention included planning and development, implementation, and process evaluation. A 3-phase process was adopted during planning and development: (1) a formative study with expectant and new mothers to explore the barriers of appropriate infant feeding practices; (2) a baseline questionnaire survey to understand potential intervention approaches; and (3) development of the text message bank. The text messaging intervention was delivered via a computer-based platform. A message bank was established before the start of the intervention containing information on the benefits of breastfeeding, preparing for breastfeeding, early initiation of breastfeeding, timely introduction of complementary foods, and establishing appropriate feeding practices, etc. An expert advisory committee oversaw the content and quality of the message bank. Process evaluation was conducted through field records and qualitative interviews with participating mothers. RESULTS: We found that the text messaging intervention was feasible and well received by mothers because of its easy and flexible access. The weekly based message frequency was thought to be appropriate, and the contents were anticipatory and trustworthy. Some mothers had high expectations for timely response to inquiries. Occasionally, the text messages were not delivered due to unstable telecommunication transmission. Mothers suggested that the messages could be more personalized. CONCLUSIONS: This study demonstrates the feasibility and value of text messaging intervention in filling gaps in delivering health care services and promoting healthy infant feeding practices in settings where personal contact is limited."

A Free CME/CE from Medscape: How Does Marijuana Use Affect Lactating Mothers?

Medscape is offering a free 0.25 CME/CE on a new lactation topic (newly released on Medscape on October 19, 2018).

Title: How Does Marijuana Use Affect Lactating Mothers?

One study cited in this short continuing ed module is the new study by Bertrand and colleagues in the journal, Pediatrics: "Marijuana use by breastfeeding mothers and cannabinoid concentrations in breast milk." Pediatrics 2018;142.…/142/3/e20181076.

A current clinical report from the AAP on the use of cannabinoids during pregnancy and lactation is also discussed. Ryan SA, Ammerman SD, O'Connor ME; COMMITTEE ON SUBSTANCE USE AND PREVENTION; SECTION ON BREASTFEEDING. Marijuana use during pregnancy and breastfeeding: implications for neonatal and childhood outcomes. Pediatrics. 2018;142.…/08/23/peds.2018-1889.

This continuing education topic and many others are available at no cost on Medscape.

A U.S. Senator and Mother Speaks Out in Support of Family Reunification

U.S. Senator Tammy Duckworth, a nursing mother, speaking at a Washington, D.C. protest today in support of family reunification:  "I wanted to show my support for the folks here today. I could only imagine what it would be like to have my daughter — my breastfeeding child — ripped away from me the way some of these other moms’ babies have been.”

Families Belong Together: USLCA Statement on Family Reunification

I send deep gratitude to the United States Lactation Consultant Association for speaking out on the immediate need for family reunification following the forced separation of infants and children from their parents at the U.S. border.  This is the USLCA Statement on Family Reunification: 

In solidarity with thousands of individuals and many organizations across the United States of America and the world, the U.S. Lactation Consultant Association calls on lawmakers to end immediately the forced separation of children from their parents at the U.S. border. This unnecessary practice is harmful to both adults and their children, and no justification for this practice should be prioritized above the health and well-being of human beings.

As International Board-Certified Lactation Consultants (IBCLCs), we work daily alongside many more breastfeeding advocates and providers of health care to support and ensure optimal health of pregnant people, parents, infants, children, and the general public through education about and assistance with breastfeeding. The IBCLC is an expert in infant feeding and is responsible to uphold scientific, evidence-informed theory and practice that is free from conflict of interest, be it financial, academic, personal, political, or otherwise.

Separation of children from their parents creates barriers to breastfeeding and safe infant feeding, and to our knowledge, no IBCLCs have been contacted with regard to how to appropriately feed infants away from their parents, to support and protect continued lactation in lactating persons who do not have access to their children for breastfeeding, or any general information about infant and young child feeding in national emergencies, natural disasters, or humanitarian crises. It is critical to understand that globally, children breastfeed far beyond infancy and that this practice is important to the health of families and the general public. The abrupt removal of the opportunity to be breastfed or to express breast milk has serious health consequences for infants, toddlers, and their lactating parents, and USLCA firmly opposes this practice in all circumstances. In addition, all major health organizations with policies about infant feeding call for the use of pasteurized donor human milk in all situations where their own parent’s milk is not available; the use of safely prepared infant formula for all children under the age of 12 months is only recommended when neither their own parent’s milk nor pasteurized donor human milk are available.

USLCA calls for the immediate and rapid reunification of families who have been separated from each other, as well as the provision of appropriate health care and support for all persons who have been directly affected by the practice of forced separation. This includes comprehensive health consultation for all facets of physiological and mental health, as well as support for resuming breastfeeding, milk expression, and education and support to ensure safe infant and young child feeding.