Donna T. Geddes

Tongue movement and intra-oral vacuum in breastfeeding infants

OBJECTIVE The mechanism by which the breastfeeding infant removes milk from the breast is still controversial. It is unclear whether the infant uses predominantly intra-oral vacuum or a peristaltic action of the tongue to remove milk from the breast. The aim of this study was to use ultrasound to observe movements of the tongue during breastfeeding and relate these movements to both milk flow and simultaneous measurements of intra-oral vacuum. METHODS Submental ultrasound scans of the oral cavity of 20 breastfed infants (3-24 weeks old) were performed during a breastfeed. Intra-oral vacuums were measured simultaneously via a milk-filled supply line (SNS) connected to a pressure transducer. RESULTS Vacuum increased during the downward motion of the posterior tongue and at the same time milk flow and milk ducts in the nipple was observed. Peak vacuum (-145+/-58 mmHg) occurred when the tongue was in the lowest position. CONCLUSIONS Ultrasound imaging demonstrated that milk flow from the nipple into the infants oral cavity coincided with both the lowering of the infants tongue and peak vacuum. Therefore vacuum is likely to play a major role in milk removal from the breast.

Frenulotomy for breastfeeding infants with ankyloglossia: effect on milk removal and sucking mechanism as imaged by ultrasound.

OBJECTIVE. There is evidence that infants with ankyloglossia can experience breastfeeding difficulties including poor attachment to the breast, suboptimal weight gain, and maternal nipple pain, which may lead to early weaning of the infant. No studies have investigated the cause of these breastfeeding difficulties. The objective of this study was to determine the effectiveness of frenulotomy in infants experiencing persistent breastfeeding difficulties despite professional assistance by measuring changes in milk transfer and tongue movement during breastfeeding before and after frenulotomy. PATIENTS AND METHODS. Twenty-four mother-infant dyads (infant age: 33 ± 28 days) that were experiencing persistent breastfeeding difficulties despite receiving professional advice were recruited. Submental ultrasound scans (Acuson XP10) of the oral cavity were performed both before and ≥7 days after frenulotomy. Milk transfer, pain, and LATCH (latch, audible swallowing, type of nipple, comfort, and hold) scores were recorded before and after frenulotomy. Infant milk intake was measured by using the test-weigh method. RESULTS. For all of the infants, milk intake, milk-transfer rate, LATCH score, and maternal pain scores improved significantly postfrenulotomy. Two groups of infants were identified on ultrasound. One group compressed the tip of the nipple, and the other compressed the base of the nipple with the tongue. These features either resolved or lessened in all except 1 infant after frenulotomy. CONCLUSIONS. Infants with ankyloglossia experiencing persistent breastfeeding difficulties showed less compression of the nipple by the tongue postfrenulotomy, which was associated with improved breastfeeding defined as better attachment, increased milk transfer, and less maternal pain. In the assessment of breastfeeding difficulties, ankyloglossia should be considered as a potential cause.

Cells in human milk: State of the science

Reflecting millions of years of adaptation and optimization, milk is unique to the species that produces it and for the young of which it is intended, with large variations in both lactation strategies and milk composition existing among different mammalian species. Despite this, milk has the consistent function of providing nourishment, protection, and developmental programming to the young, with short- and long-term effects. Among its components that confer these functions, breast milk contains maternal cells, from leukocytes to epithelial cells of various developmental stages that include stem cells, progenitor cells, lactocytes, and myoepithelial cells. Although in the first 150 years since their discovery, breast milk cells were mostly studied for their morphological traits, technological advances in the last decade have allowed characterization of breast milk cell types at the protein and messenger RNA levels. This is now paving the way for investigation of the functions of these cells in the breastfed infant and the use of breast milk as a tool to understand the normal biology of the breast and its pathologies. This review summarizes the current knowledge of breast milk cellular heterogeneity and discusses future prospects and potential applications.

Oxygen Saturation and Suck-Swallow-Breathe Coordination of Term Infants during Breastfeeding and Feeding from a Teat Releasing Milk Only with Vacuum

Background. Vacuum is an important factor in milk removal from the breast, yet compression is the predominant component of milk removal from bottle teats. Since bottle-feeding infants have lower oxygen saturation, vacuum levels, and different suck-swallow-breathe (SSwB) coordination to breastfeeding infants, we hypothesised that when infants fed from a teat that required a vacuum threshold of −29 mmHg for milk removal, that oxygen saturation, heart rate, and suck-swallow-breathe (SSwB) patterns would be similar to those of breastfeeding. Study Design. Infants (n = 16) were monitored during one breastfeed and one feed from the experimental teat. Simultaneous recordings were made of oxygen saturation, heart rate, vacuum, tongue movement, respiration, and swallowing. Results. There were no differences in oxygen saturation and heart rate between the breast and the teat. Infants displayed fewer sucks and breaths per swallow during nutritive sucking (NS) compared to non-nutritive sucking (NNS). The number of sucks per breath was similar for NS and NNS although respiratory rates were slower during NS. These patterns did not differ between the breast and the teat. Conclusion. These results suggest that vacuum may be conducive to safe and coordinated milk removal by the infant during both breast and bottle-feeding.

Anatomy of the Human Mammary Gland: Current Status of Knowledge

Mammary glands are unique to mammals, with the specific function of synthesizing, secreting, and delivering milk to the newborn. Given this function, it is only during a pregnancy/lactation cycle that the gland reaches a mature developmental state via hormonal influences at the cellular level that effect drastic modifications in the micro‐ and macro‐anatomy of the gland, resulting in remodeling of the gland into a milk‐secretory organ. Pubertal and post‐pubertal development of the breast in females aids in preparing it to assume a functional state during pregnancy and lactation. Remarkably, this organ has the capacity to regress to a resting state upon cessation of lactation, and then undergo the same cycle of expansion and regression again in subsequent pregnancies during reproductive life. This plasticity suggests tight hormonal regulation, which is paramount for the normal function of the gland. This review presents the current status of knowledge of the normal macro‐ and micro‐anatomy of the human mammary gland and the distinct changes it undergoes during the key developmental stages that characterize it, from embryonic life through to post‐menopausal age. In addition, it discusses recent advances in our understanding of the normal function of the breast during lactation, with special reference to breastmilk, its composition, and how it can be utilized as a tool to advance knowledge on normal and aberrant breast development and function. Finally, anatomical and molecular traits associated with aberrant expansion of the breast are discussed to set the basis for future comparisons that may illuminate the origin of breast cancer. Clin. Anat. Clin. Anat. 26:29–48, 2013.

Importance of Vacuum for Breastmilk Expression

OBJECTIVE To determine the effect of the strength of applied vacuum on the flow rate and yield of breastmilk using an electric breast pump. STUDY DESIGN Twenty-one breastfeeding mothers and two expressing mothers expressed their breastmilk for 15 minutes using an electric breast pump set at their own maximum comfortable vacuum, and at one to three softer vacuums. Milk yield and flow rate were measured. RESULTS At the maximum comfortable vacuum (-190.7 +/- 8.8 mm Hg) 4.3 +/- 0.4 milk ejections occurred during 15 minutes of expression and yielded 118.5 +/- 11.4 mL of milk (65.5 +/- 4.1% of the available milk). Softer vacuums yielded less milk volume (p < 0.05) and less of the available milk (p < 0.01). Milk flow rate was greater during the first milk ejection than the third or subsequent milk ejections (p < 0.001). Cream content of the milk was highest after expressing for 15 minutes using the mothers maximum comfortable vacuum. CONCLUSIONS Use of the mothers maximum comfortable vacuum enhances milk flow rate and milk yield. The cream content of the milk at the end of the expression period was an indicator of how effectively the breast had been drained.

MicroRNAs in Breastmilk and the Lactating Breast: Potential Immunoprotectors and Developmental Regulators for the Infant and the Mother

Human milk (HM) is the optimal source of nutrition, protection and developmental programming for infants. It is species-specific and consists of various bioactive components, including microRNAs, small non-coding RNAs regulating gene expression at the post-transcriptional level. microRNAs are both intra- and extra-cellular and are present in body fluids of humans and animals. Of these body fluids, HM appears to be one of the richest sources of microRNA, which are highly conserved in its different fractions, with milk cells containing more microRNAs than milk lipids, followed by skim milk. Potential effects of exogenous food-derived microRNAs on gene expression have been demonstrated, together with the stability of milk-derived microRNAs in the gastrointestinal tract. Taken together, these strongly support the notion that milk microRNAs enter the systemic circulation of the HM fed infant and exert tissue-specific immunoprotective and developmental functions. This has initiated intensive research on the origin, fate and functional significance of milk microRNAs. Importantly, recent studies have provided evidence of endogenous synthesis of HM microRNA within the human lactating mammary epithelium. These findings will now form the basis for investigations of the role of microRNA in the epigenetic control of normal and aberrant mammary development, and particularly lactation performance.

Human milk miRNAs primarily originate from the mammary gland resulting in unique miRNA profiles of fractionated milk

Human milk (HM) contains regulatory biomolecules including miRNAs, the origin and functional significance of which are still undetermined. We used TaqMan OpenArrays to profile 681 mature miRNAs in HM cells and fat, and compared them with maternal peripheral blood mononuclear cells (PBMCs) and plasma, and bovine and soy infant formulae. HM cells and PBMCs (292 and 345 miRNAs, respectively) had higher miRNA content than HM fat and plasma (242 and 219 miRNAs, respectively) (p < 0.05). A strong association in miRNA profiles was found between HM cells and fat, whilst PBMCs and plasma were distinctly different to HM, displaying marked inter-individual variation. Considering the dominance of epithelial cells in mature milk of healthy women, these results suggest that HM miRNAs primarily originate from the mammary epithelium, whilst the maternal circulation may have a smaller contribution. Our findings demonstrate that unlike infant formulae, which contained very few human miRNA, HM is a rich source of lactation-specific miRNA, which could be used as biomarkers of the performance and health status of the lactating mammary gland. Given the recently identified stability, uptake and functionality of food- and milk-derived miRNA in vivo, HM miRNA are likely to contribute to infant protection and development.

The Effect of UV-C Pasteurization on Bacteriostatic Properties and Immunological Proteins of Donor Human Milk

Background Human milk possesses bacteriostatic properties, largely due to the presence of immunological proteins. Heat treatments such as Holder pasteurization reduce the concentration of immunological proteins in human milk and consequently increase the bacterial growth rate. This study investigated the bacterial growth rate and the immunological protein concentration of ultraviolet (UV-C) irradiated, Holder pasteurized and untreated human milk. Methods Samples (n=10) of untreated, Holder pasteurized and UV-C irradiated human milk were inoculated with E. coli and S. aureus and the growth rate over 2 hours incubation time at 37°C was observed. Additionally, the concentration of sIgA, lactoferrin and lysozyme of untreated and treated human milk was analyzed. Results The bacterial growth rate of untreated and UV-C irradiated human milk was not significantly different. The bacterial growth rate of Holder pasteurized human milk was double compared to untreated human milk (p<0.001). The retention of sIgA, lactoferrin and lysozyme after UV-C irradiation was 89%, 87%, and 75% respectively, which were higher than Holder treated with 49%, 9%, and 41% respectively. Conclusion UV-C irradiation of human milk preserves significantly higher levels of immunological proteins than Holder pasteurization, resulting in bacteriostatic properties similar to those of untreated human milk.

Infants of mothers with persistent nipple pain exert strong sucking vacuums

Aim: The objective of this study was to determine whether infants of mothers experiencing persistent nipple pain exerted very strong intraoral vacuums during a breastfeed.