DANTE-SPACE can be used for visualizing intracranial vessel walls at 7T, where the flow-sensitive signal attenuation of the DANTE preparation simultaneously suppresses signal from the internal blood and external CSF. However, the efficacy of DANTE is reduced for blood moving upstream through the neck due to limited B1 + coverage at 7T. Here, EPG simulations are used to estimate the effect of this limited B1 + coverage on the achieved contrasts. A pTx-based approach which uses separate RF shims for the DANTE-preparation and the SPACE readout to improve the attenuation of blood moving through the neck is proposed, and validated in vivo .

A perception of insufficient milk supply (PIMS) is associated with early discontinuation of breastfeeding. Ideally, an objective measure of milk supply would either dispel or confirm this perception and provide reassurance or guide professional advice. Clinical signs of sufficient milk intake (steady growth, sufficient elimination, infant alertness and breasts feeling full before breastfeeds and soft after breastfeeds) should provide confidence in milk supply. We surveyed 423 mothers in early lactation who had breastfeeding problems to determine the proportion that had PIMS and to determine if the mothers with PIMS relied on these clinical signs or other perceptions of their infants' behaviour as indications of insufficient milk supply. By 3 weeks after birth, we found that the rate of PIMS among mothers with breastfeeding problems was 44%. Supplementary infant formula was being given to 66% of the infants, so the clinical indications were that milk intake was sufficient, but 74% of the mothers with PIMS cited concerns that their infants did not appear satisfied after breastfeeds. After targeted advice from lactation consultants, mothers with PIMS showed positive changes in their perceptions of their milk supply, underlining the value of professional guidance soon after birth. We conclude that an appearance of infant dissatisfaction is the major cause of PIMS in Western Australia.

Researchers have recently called for human lactation research to be conceptualized as a biological framework where maternal and infant factors impacting human milk, in terms of composition, volume and energy content are studied along with relationships to infant growth, development and health. This approach allows for the development of evidence-based interventions that are more likely to support breastfeeding and lactation in pursuit of global breastfeeding goals. Here we summarize the seminal findings of our research programme using a biological systems approach traversing breast anatomy, milk secretion, physiology of milk removal with respect to breastfeeding and expression, milk composition and infant intake, and infant gastric emptying, culminating in the exploration of relationships with infant growth, development of body composition, and health. This approach has allowed the translation of the findings with respect to education, and clinical practice. It also sets a foundation for improved study design for future investigations in human lactation.

Quantification of human milk (HM) fat is important for determining the energy intake of infants. The simplest and most rapid method is the creamatocrit method. However, the reliability of the creamatocrit has not been comprehensively investigated. The aims of this study were to test the inter- and-intra-rater reliability of: 1) HM sampling after hand- or-machine mixing methods and 2) HM fat measurement by the creamatocrit method. Interand-intra rater HM sampling after hand- or-machine mixing methods had high intraclass correlation coefficient ( 2%) resulted in high variability (median coefficient of variations (CVs) 15%). Intra- and inter-rater reliability of measurement of HM with higher fat (>3.5%) had low variability (median CVs < 10%). As the greatest variation in the creamatocrit method occurred during the measurement of HM samples with low fat, duplicate readings are necessary to reduce discrepancies in every HM fat determination.

Background Milk ejection characteristics remain consistent throughout 12 months of lactation in women who expressed breastmilk with an electric breast pump. In addition these characteristics appear to remain constant when women are breastfeeding or pumping suggesting that milk ejection is a robust physiological response. It is not known whether the stimulation of an infant at the breast in the early post partum period influences milk ejection patterns or whether this is a programmed event. However, as more data become available on the mechanisms involved in infant feeding, pumping patterns mimicking the infant more closely may provide enhanced results. The objective of this study was to compare milk ejection characteristics obtained when using a novel infant-derived pumping pattern with an established 2-phase pattern. Methods A convenience sample of ten lactating mothers, 1 to 40 weeks of lactation with normal milk production were recruited in 2015. Each participated in two pumping sessions in which either a 2-phase pattern or infant-derived pattern were randomly assigned. Milk volume and milk ejection characteristics were recorded and the percentage of available milk removed (PAMR) was calculated. Statistical analysis used linear mixed effects modeling to determine any differences between breasts and pump patterns with the consideration of individual variability as a random effect. Results The number of milk ejections and milk ejection characteristics did not differ between patterns. Milk volumes removed were 53.6 ± 28.5 ml (PAMR 58.2 ± 28.4) for the 2-phase pattern and and 54.2 ± 26.3 ml (PAMR 52.2 ± 22.3) for the infant derived pattern. Peak milk flow rates were positively associated with the available milk ( p = 0.0003) and PAMR ( p = 0.0001), as was the volume of milk removed during each milk ejection ( p = 0.001 and p = 0.0001). Conclusion An experimental pumping pattern designed to resemble infant sucking characteristics did not alter milk ejection characteristics or milk removal parameters compared with an established 2-phase pattern. Theses findings provide further evidence that milk ejection is a robust physiological response.

AimTo determine the impact of the pumping regimes of women with preterm infants on the daily milk production, and on the short-term rate of milk synthesis during early lactation to support evidence-based recommendations for optimising milk production.MethodsMothers of preterm infants (n=25) recorded start time, finish time and expression volumes from every breast expression on days 10, 15–20 postpartum.ResultsExpressing more often than five times per day did not result in a significant increase in daily milk production. Milk volume per expression per breast increased for intervals between expressions of between 2and6 hours then reached a plateau when the interval between expression was 7 hours or longer. The short-term rate of milk synthesis decreased as the interval between expressions increased until about 7.5 hours at which point it begun to increase (p value associated with interval between expressions^2<0.001).ConclusionThe strong inverse association between the short-term rate of milk synthesis and the interval between expressions for intervals up to 7 hours suggest that the maximum interval between expressions should be 7 hours. Data suggest that, on average, the mothers should express at least five times a day to maximise daily milk production. Considering inter-individual variation, determination of an individual mother’s maximum interval between expressions that does not compromise the short-term rate of milk synthesis will help to optimise daily milk production while minimising the demands on the mother’s time.

Objective measurement of the rate of synthesis of breast milk and fat in breastfeeding mothers requires test-weighing of each breastfeed and the measurement of each expression from each breast over 24 h, with the collection of milk samples before and after each breastfeed and expression. We sought an abbreviated technique for measuring these rates of synthesis. Participants completed a 24-h breastfeeding milk profile, and expressed their breasts on arrival at the research room and each hour thereafter for 3 h (4 expressions). The hourly rate of milk synthesis, as measured by the yield of milk from the fourth expression, was closely related to the hourly rate of milk synthesis calculated from the 24-h milk profile. The hourly rate of fat synthesis, calculated from the fat content of small samples of the first and last milk expressed during the fourth expression, was different from the rate of fat synthesis calculated from the fat content and volumes of all the breastfeeds and expressions during the 24-h milk profile. The study confirms the use of an abbreviated technique to measure the rate of breast milk synthesis, but is not reliable as a measure of the rate of fat synthesis for an individual.

OBJECTIVE:Milk ejection is a critical physiological process for successful lactation in humans and without it little milk can be removed. Individual milk ejection patterns have been shown to remain consistent between breasts at different lactation stages and using different vacuum patterns with an electric breast pump. Little is known about the milk ejection characteristics during the second lactation period in the same mother. The objective of this study was to examine milk ejection characteristics in the same woman over two lactations.METHODS:One mother took part in two pumping studies during consecutive lactations. One pumping study examined milk ejection characteristics during simultaneous breast expression during the first lactation. The second pumping study (second lactation) used two different pumping patterns. Three distinct milk ejections were measured during each pumping session.RESULTS:Measurements of milk flow were used to compare the duration and time taken to reach the peak of each milk ejection for two pumping sessions from each of the lactations. There were no significant differences in milk ejection characteristics between breasts, using different pumping patterns, or between lactations in this mother (P > .05).CONCLUSION:Milk ejection appears to be a physiological response that is consistent across consecutive lactations within the same mother. This suggests that milk ejection characteristics are established during or prior to the first lactation. The infant appears to have little influence on the milk ejection characteristics of the mother.

IntroductionPerceived or actual low milk supply is the leading cause of early breastfeeding cessation worldwide. Monitoring 24 hour milk production profiles can help diagnose low milk production which may be improved with pumping regimes and support. Despite this, some cases of low milk production persist. Human milk cells are increasingly being utilised to provide non‐invasive access to mammary epithelial cells allowing investigations into lactocyte characteristics and metabolism.Problem StatementThe molecular mechanisms behind impaired lactation in the female mammary gland are not well understood.Procedures/Data/ObservationsThis study examines human milk cell gene expression from 12 participants with low milk production profiles (<600 mL in 24 hrs) and 14 participants with normal production profiles (>600 mL in 24 hrs). Genes (n=28) were examined using quantitative reverse transcription polymerase chain reaction (qRT‐PCR) and were representative of progenitor and myoepithelial cells and lactocytes, as well as genes identified as intrinsic to milk production. Students t‐test was used to compare gene expression between the two groups. Alternatively, Welch's t‐test was used in the case of unequal variances as determined by Bartlett's test.ResultsInitial analysis found cells isolated from women with low milk production showed significantly lower expression of the genes estrogen related receptor beta (ESRRB, p=0.027) and neurotrophin receptors sortilin (SORT, p=0.010) and tyrosine receptor kinase 2 splice variant 1 (TRKB1, p=0.007) and higher expression of a progenitor marker (REX1, p=0.025) compared with cells isolated from women with normal production.ConclusionsPreliminary findings suggest variations in cell signalling and function, examined through gene expression that might contribute to low milk production. Further investigations will potentially determine significant roles of key genes enabling successful human lactation.Support or Funding InformationThis research was funded by an unrestricted research grant from Medela AG.

Study objectiveCurrently measurement of the average rate of breast milk synthesis and fat synthesis relies on a 24‐h milk profile (test‐weighing all breastfeeds and expressions over a 24‐h period and collecting small milk samples before and after each breastfeed for the same period). It has been demonstrated that when the breasts are expressed using an electric breast pump each hour, the volume of the fourth expression is equivalent to the hourly rate of milk synthesis. We aimed to confirm this finding, and ascertain if the same technique could be used to estimate the rate of milk fat synthesis.MethodsThe study was approved by the Human Research Ethics Committee of The University of Western Australia and all participants provided written informed consent. Mothers (n = 15) measured their 24‐h milk profile, and then expressed their breast(s) using a Medela Symphony breast pump for 10 min on arrival at the research room, and 1, 2 and 3 hours later. The volume of milk expressed each time was measured and small (<1 mL) milk samples collected before and after each expression. The creamatocrit of each sample was measured and converted to fat using the formula fat (g.L−1) = 3.968 + (5.917*creamatocrit). Linear mixed models were used to compare the volumes and fat content at each hourly expression with the hourly milk yield and fat synthesis from the 24‐h milk profile. Random effect was the mother.ResultsThe mean rates of milk synthesis were 17.8 mL.h−1 (sem 2.0) and 19.0 mL.h−1 (sem 2.0) for 24‐h milk profile and fourth expression, respectively, and there was a significant relationship between the two measurements (P=0.002). The slope of the regression was 0.66 with a confidence interval of 0.32 – 1.00). The mean rates of fat synthesis were 0.75 g.h−1 (sem 0.06) and 0.96 g.h−1 (sem 0.13) for 24‐h milk profile and fourth expression, respectively, and there was a significant relationship between the two measurements (P=0.039). The slope of the regression was 1.14 with a confidence interval of 0.20 – 2.08.ConclusionThese data confirm that the fourth hourly expression can be used to estimate the average rate of breast milk synthesis for individuals. However, while there is an overall relationship between the two methods for estimating the rate of synthesis of milk fat, the wide confidence interval for the slope of the regression implies that this technique is less useful for individuals.Support or Funding InformationUnrestricted research grant from Medela AG

Breastmilk provides the ideal nutrition for the infant, and exclusive breastfeeding is recommended for the first 6 months. Adequate milk production by the mother is therefore critical, and early milk production has been shown to significantly affect milk production during established lactation. Previous studies indicate that milk production should reach the lower limit of normal for established lactation (440 mL per day) by day 11 after birth. We have used test-weighing of term infants before and after each breastfeed over 24 h to measure milk production in the first 4 weeks of lactation in mothers with and without perceived breastfeeding problems to provide information on how often milk production is inadequate. Between days 11 and 13, two-thirds of the mothers had a milk production of less than 440 mL per day, and between days 14 and 28, nearly one-third of the mothers had a milk production of less than 440 mL per day. The high frequency of inadequate milk production in early lactation and the consequence of suboptimal milk production in later lactation if left untreated suggest that objective measurement of milk production can identify mothers and infants at risk and support early intervention by a lactation specialist.

Aim: The duration of exclusive breastfeeding is affected by maternal confidence and perception of milk supply, but objective measurement of milk supply is rarely used. Mothers of preterm infants have found measuring milk supply by in-home test weighing to be helpful to ascertain their infants' breastfeeding intake. This study aimed to determine if this technique affects breastfeeding confidence of mothers of term infants. Materials and Methods: Participants filled in a survey of their breastfeeding confidence and perceptions of breastfeeding behavior prior to and after a 24-hour period of recording the times of feeds, amounts of each breastfeed or bottle feed (expressed breastmilk or formula), and amounts of breastmilk expressed. Results: The breastfeeding confidence of at least 66% of mothers who were initially confident was maintained, and the breastfeeding confidence of at least 11% of mothers who were initially not confident was improved after objective measurement of milk supply and breastfeeding behavior. Conclusions: Measurement of actual milk supply and breastfeeding behavior provides objective information that can guide clinicians in the management of lactation. It can also help to maintain or improve breastfeeding confidence.

Milk ejection is a transient episode critical to milk removal and women typically have multiple milk ejections during breastfeeding and pumping. Recently it was found that milk ejection characteristics such as number of milk ejections and periodicity were consistent throughout 12 months of lactation in women who expressed their milk with an electric breast pump. It is not known whether the stimulation of an infant at the breast influences milk ejection patterns or whether this is a programmed event. The aim of this study was to compare milk ejection patterns during breastfeeding and expressing milk with an electric pump within mothers.

Background: Infants of breastfeeding mothers with persistent nipple pain have been shown to apply stronger vacuums to the breast and transfer less milk during one monitored feed. This may be associated with differences in the movement of the tongue. The aim was to analyse the intra-oral nipple shape and movement of the tongue of infants of mothers with and without nipple pain. Methods: Breastfeeding infants of mothers with or without nipple pain were monitored using ultrasound and intra-oral vacuum during one breastfeed. From cine clips of the ultrasound scans measurements were made of the depth of the intra-oral space between the hard-soft palate junction (HSPJ) and the mid-tongue; the distance of the tip of the nipple to the HSPJ; and nipple diameters from the tip to the base. Results: During nutritive sucking, tongue movements of infants of mothers with nipple pain resulted in a smaller intra-oral space (p = 0.040) and restricted nipple expansion compared to controls (p < 0.012). Stronger baseline and peak vacuums compared to controls were confirmed (p = 0.002). Conclusion: In these mothers, nipple pain was associated with restricted infant tongue movement. Ultrasound may complement measurement of intra-oral vacuum in monitoring treatment strategies in breastfeeding women experiencing nipple pain.

Background: Persistent nipple pain is one of the most common reasons given by mothers for ceasing exclusive breastfeeding. We aimed to determine the frequency of nipple pain as a reason for consultation, the most common attributed aetiologies, and the effectiveness of the advice and treatment given. Methods: All consultations at the Breast Feeding Centre of Western Australia (WA) were audited over two six-month periods in 2011 (n = 469) and 2014 (n = 708). Attributed cause(s) of nipple pain, microbiology results, treatment(s) advised, and resolution of pain were recorded. Results: Nipple pain was one of the reasons for consultation in 36% of cases. The most common attributed cause of nipple pain was incorrect positioning and attachment, followed by tongue tie, infection, palatal anomaly, flat or inverted nipples, mastitis, and vasospasm. Advice included correction of positioning and attachment, use of a nipple shield, resting the nipples and expressing breastmilk, frenotomy, oral antibiotics, topical treatments, and cold or warm compresses. Pain was resolving or resolved in 57% of cases after 18 days (range 2–110). Conclusion: The multiple attributed causes of nipple pain, possibly as a result of a cascade of events, suggests that effective early lactation management for prevention of nipple pain and early diagnosis and effective treatment are crucial to avoid early weaning.

BACKGROUND:Milk production is under the influence of autocrine control such that the rate of milk synthesis decreases as the breast fills with milk. Effective elimination of milk from the alveoli via the milk ejection reflex will therefore result in increased milk synthesis. It has been assumed that milk ejection occurs in all alveoli simultaneously; however, animal studies have indicated that full alveoli eject milk sooner than less full alveoli, suggesting heterogeneous emptying of the mammary gland.OBJECTIVE:The aim of this study was to determine whether milk ejection occurs asynchronously in the human lactating breast.METHODS:Retrospective analysis of videos made of ultrasound monitoring of milk ducts during pumping. Six video clips (4 women) of ultrasound monitored milk ejections showed obvious differences in the timing of milk flow between different main milk ducts. Duct diameter was simultaneously measured every second in 2 different ducts that drained 2 separate lobes of the breast.RESULTS:For 5 of 6 ultrasound duct monitoring sessions, both duct dilation and visualization of milk flow in the 2 separate main milk ducts differed by 2 to 8 seconds. For the remaining woman, milk was observed to eject from 1 part of the lobe, and when not removed, it flowed in a retrograde fashion into a different part of the lobe.CONCLUSION:Asynchrony of milk ejection occurs in the human lactating breast, suggesting that the timing of myoepithelial cell response differs, resulting in heterogeneous emptying of the gland.

This study aimed to provide insight into nipple pain in breastfeeding mothers focusing on the microbiology, treatments and subsequent outcomes. For a 6‐month period, data were retrieved from the lactation consultant records of 489 clients of the Breast Feeding Centre of WA. Nipple pain was identified in 36% of the clients. Nipple swabs were collected from 46% of the clients with nipple pain when infection was clinically suspected as the cause. The rate of detected infection was 61%. Staphylococcus species were present in 90% of the positive cultures. Other infective organisms detected were a variant of the Streptococcus species, Acinetobacter baumannii, Pseudomonas stutzeri and Candida. Targeted treatment was provided for 77% of the mothers who were positive. Antibiotic choice included flucloxacillin alone or with a combination of other antimicrobials or antifungals, cephalexin, or cephalosporin, depending on the sensitivity of the organism grown from the swab to antibiotics. Fluconazole was prescribed when candida was detected. The treatment resulted in the nipple pain resolving or resolved in 71% of cases. We conclude that swabbing painful nipples during lactation can provide successful, targeted treatment.Grant Funding Source: Supported by Medela, AG

Objective: The most common reason given for discontinuation of exclusive breastfeeding is perceived insufficient milk supply. Breastfed infants show more variation in feeding frequency than bottle-fed infants, and this may lead to a mother lacking confidence in her milk supply if the frequency of breastfeeding sessions does not match expectations based on bottle feeding. We aimed to assist clinicians in supporting breastfeeding mothers by providing evidence-based information on expected changes in breastfeeding patterns and milk intake during exclusive breastfeeding for 6 months. Subjects and Methods: Mothers and their healthy infants who were exclusively breastfeeding (total 24-hour milk intake within the normal range) were studied during two to five 24-hour periods between 1 and 6 months of lactation. Results: Between 1 and 3 months of lactation, the frequency of breastfeeding sessions decreased, whereas both the median and maximum breastmilk intakes during each breastfeeding session increased. These parameters remained constant between 3 and 6 months. The duration of each breastfeeding session decreased steadily from 1 to 6 months, but the total 24-hour milk intake remained constant. Conclusions: Breastfeeding becomes more efficient between 1 and 3 months of lactation, although milk intake remains constant. Clinicians can give mothers confidence that these changes in breastfeeding behavior do not indicate insufficient milk supply, but may be a result of the increase in the stomach capacity of the infants and are an expected outcome of a healthy, normal breastfeeding relationship.

BACKGROUND:Despite the differences in breastfeeding and bottle-feeding, our understanding of how suck-swallow-breathe (SSwB), oxygenation, and heart rate patterns change as the infant ages is based predominantly on bottle-feeding studies. Therefore, this study aimed to measure how SSwB, oxygenation, and heart rate patterns changed during the first 4 months of lactation in term breastfeeding infants.METHODS:Infants less than 1 month postpartum (n = 15) were monitored early in lactation and again later in lactation (2-4 months postpartum). Simultaneous recordings of vacuum, tongue movement, respiration, swallowing, oxygen saturation, and heart rate were made during both nutritive sucking and non-nutritive sucking during breastfeeding.RESULTS:Infants transferred a similar amount of milk (P = .15) over a shorter duration later in lactation (P = .04). Compared to early lactation, suck bursts became longer (P < .001), pauses became shorter (P < .001), vacuum levels decreased (all P < .05), oxygen saturation increased (P < .001), and heart rate decreased (P < .001) later in lactation.CONCLUSION:This study confirmed that term infants become more efficient at breastfeeding as they age, primarily by extending their suck bursts and pausing less. Although infants demonstrated satisfactory SSwB coordination during early lactation, they showed a level of adaption or conditioning at later lactation by applying weaker vacuum levels and demonstrating improved cardiorespiratory responses.