Using milk flow rate to investigate milk ejection in the left and right breasts during simultaneous breast expression in women

<p>Abstract</p> <p>Background</p> <p>Milk ejection is essential for a successful lactation, however techniques to measure milk ejection in women are often complex and invasive. Recent research has demonstrated that at milk ejection, milk duct diameter increased in the breast (measured by ultrasound) at the same time as milk flow rate increased (measured using a weigh balance). This study aimed to evaluate a purpose-built continuous weigh balance (Showmilk, Medela AG) to measure changes in milk flow rate from the breast to identify milk ejections during milk expression. In addition, the Showmilk was used to determine if milk ejection occurred simultaneously in both breasts during double pumping.</p> <p>Methods</p> <p>Increased milk flow rates during single pumping were compared to simultaneous ultrasound measurements of increased milk duct diameters in 14 mothers. In addition, increases in milk flow rate were compared between the left and right breasts of 28 mothers during double pumping for 15 minutes with two separate electric breast pumps attached to two Showmilks to record milk flow rate.</p> <p>Results</p> <p>Increased milk flow rates were associated with increased milk duct diameters during single pumping. The mean number of milk ejections was not different between the Showmilk (4.2 ± 2.0) and ultrasound (4.5 ± 1.5) techniques. Overall, 67 milk ejections were measured and of these, 48 (72%) were identified by both techniques. The left and right breasts responded synchronously with 95.5% of the flow rate increases corresponding between the breasts. The mean number of milk ejections identified by an increase in milk flow rate during double pumping was 5.1 ± 1.7 and 5.0 ± 1.7 for the left and right breasts, respectively. In addition, mothers chose the same expression vacuum for the left (-198 ± 31 mmHg) and right (193 ± 33 mmHg) breasts.</p> <p>Conclusion</p> <p>The Showmilk can simply and non-invasively record milk ejections by measuring increases in milk flow rate that correspond with increases in milk duct diameter. For the first time measurement of milk flow rate has been used to confirm that milk ejections occur simultaneously in the left and right breasts during double pumping. The use of the Showmilk will facilitate further research into the relationship of milk ejection and milk removal.</p

Investigation of short-term variations in term breast milk composition during repeated breast expression sessions

Background: Breast milk composition can be affected by several factors, and it can exhibit short-term (weekly) variations. Investigating variations in breast milk composition is important to accurately estimate nutrient requirements of the infant. Objective: To investigate short-term changes in breast milk composition between left and right breasts, over a 3-week period within the first 6 months of lactation. Methods: The left and right breasts of the mothers of healthy, term infants (n = 23) were simultaneously expressed with an electric breast pump for 15 minutes, on 3 occasions within 3 weeks. Milk samples (5 mL) were collected from the total expression volume of each breast at each session. The macronutrient contents, total solids, and energy content were determined using a mid-infrared human milk analyzer. Mothers (n = 17) measured their 24-hour milk production, and the average 24-hour fat contents were also determined. Results: Over the 3 weekly sessions, no significant changes were found in macronutrient contents. On average, total solids (P = .04) and energy (P = .04) decreased by week 3 of follow-up sessions from 14 to 13 g/100 mL and from 82 to 76 Kcal/100 mL, respectively; however, these changes became insignificant when expression volume was taken into account. The macronutrient concentration was similar for the left and right breasts; however, milk composition varied markedly between mothers. Furthermore, average 24-hour fat content was significantly lower than the mean fat content from a single expression session (P \u3c .01). Conclusion: Our findings highlight that when determining the nutritional adequacy of a mother’s milk, assuming an average concentration requires caution. The study findings illustrate the importance of using average 24-hour fat content of milk to obtain representative measures of infant energy intake

Variation in fat, lactose, and protein composition in breast milk over 24 hours associations with infant feeding patterns

Background: Data regarding the association between breast milk composition and infant feeding patterns (frequency and amount of breast milk taken) would help in understanding the regulation of food intake in breastfed infants. Objective: This study examined the relationship between breast milk macronutrient concentration and patterns of milk intake in breastfeeding infants over a 24-hour breastfeeding period. Methods: Mothers of healthy term infants (n = 15) collected pre- and postfeed breast milk samples from each feed at each breast over a 24-hour period. Breast milk samples were analyzed for fat, lactose, total protein, casein, and whey protein content. The energy content for each feed was calculated. Results: Breastfeeding patterns and milk composition varied greatly between individuals. The fat content of milk significantly differed over 24 hours (P = .01), whereas the concentration of lactose and protein content remained the same. The mean 24-hour total protein, whey, and casein intake was inversely (P \u3c .01), whereas lactose concentration was positively (P = .03) related to the number of breast feeds per day. No relationship was seen either between fat or energy content and feeding patterns. The mean (SD) concentration of fat, lactose, and total protein over the 24-hour period was 43 (12) g/L, 68 (7) g/L, and 13 (2) g/L, respectively. Conclusion: The association between milk protein intake and the breastfeeding frequency suggests that the protein intake may play a role in infant appetite control

Investigation of short-term variations in casein and whey proteins in breast milk of term mothers

Objectives: We investigated changes in breast milk whey and casein proteins, between fore and hind milk during breast expression, between breasts and within 24-hour period during breast-feeding. This has implications for developing an appropriate sampling protocol for investigating the influence of milk composition on gastric emptying and infants’ feeding behaviour. Methods: Breast milk samples were collected from mothers (n = 25) of healthy term infants ages 1 to 8 months. A total of 17 mothers provided fore and hind milk samples, which were collected during simultaneous expression of both breasts. Fifteen mothers provided samples from each breast-feed during 24-hour period, of which samples were selected from 4 time points (morning, day, evening, night). Whey and casein were isolated from skim milk, and protein concentration of the skim, whey, and casein fractions were determined. Results: Mean protein concentrations were found to be 13.5 ± 2.1 (skim milk), 7.6 ± 1.5 (whey), and 3.4 ± 0.97 g/L (casein). Protein concentrations were not significantly different between fore and hind milk. During a 24-hour period, no significant differences were found in protein concentration of any fraction at the 4 time points or between left and right breasts. Large variations were seen between mothers with coefficient of variances of 15.5%, 19.8%, and 28.4% for skim milk, whey, and casein, respectively. Conclusions: Although there was wide variation between mothers, the small variations within mothers indicate that for sampling purposes, a single breast milk sample (fore or hind from each breast at any time point of the day) will be representative of that mother\u27s protein concentration of skim, whey, and casein fractions for that day

Breastmilk Is a novel source of stem cells with multilineage differentiation potential

The mammary gland undergoes significant remodeling during pregnancy and lactation, which is fuelled by controlled mammary stem cell (MaSC) proliferation. The scarcity of human lactating breast tissue specimens and the low numbers and quiescent state of MaSCs in the resting breast have hindered understanding of both normal MaSC dynamics and the molecular determinants that drive their aberrant self-renewal in breast cancer. Here, we demonstrate that human breastmilk contains stem cells (hBSCs) with multilineage properties. Breastmilk cells from different donors displayed variable expression of pluripotency genes normally found in human embryonic stem cells (hESCs). These genes included the transcription factors (TFs) OCT4, SOX2, NANOG, known to constitute the core self-renewal circuitry of hESCs. When cultured in the presence of mouse embryonic feeder fibroblasts, a population of hBSCs exhibited an encapsulated ESC-like colony morphology and phenotype and could be passaged in secondary and tertiary clonogenic cultures. While self-renewal TFs were found silenced in the normal resting epithelium, they were dramatically upregulated in breastmilk cells cultured in 3D spheroid conditions. Furthermore, hBSCs differentiated in vitro into cell lineages from all three germ layers. These findings provide evidence that breastmilk represents a novel and noninvasive source of patient-specific stem cells with multilineage potential and establish a method for expansion of these cells in culture. They also highlight the potential of these cells to be used as novel models to understand adult stem cell plasticity and breast cancer, with potential use in bioengineering and tissue regeneration