Caffeine Concentrations in Human Milk Donated to a Human Milk Bank in Japan.

BACKGROUND: Human milk banks have been established to provide human milk to preterm infants who are unable to obtain milk from their mothers. Donor screening methods vary, and prospective donors are commonly screened for drug and recreational substance use through behavioral screening. Although the risk of illegal drug consumption in Japan is extremely low, caffeine may be consumed unknowingly and can be found in human milk. To date, only a few reports have been conducted on the concentration of caffeine in donor milk. RESEARCH AIM: This study aimed to examine the pre-pasteurization levels of caffeine in human milk donated to a milk bank in Japan. METHODS: This was a cross-sectional, observational study of caffeine concentrations in human milk donated to a human milk bank in Japan. Caffeine concentration in the donor milk was measured using high-performance liquid chromatography. RESULTS: Caffeine was detected in 70% of the donor milk samples (N = 350). The median (range) of caffeine concentration was 0.46 [< 0.10, 7.54] mg/L, and 64.0% of the samples had less than 1 mg/L of caffeine. The caffeine concentration varied widely among as well as within individuals. CONCLUSION: The average caffeine concentration in Japanese donor milk samples was higher than that previously reported in samples from Spain, but the range was similar. Donors should be informed that caffeine intake should be within a moderate range, to further increase the safety of donor milk.

Comparison of bacterial profiles in human milk from mothers of term and preterm infants.

BACKGROUND: Reducing the disposal of donated human milk (HM) is important for efficient management of human milk banks (HMBs). The presence of bacteria growth is the main factor that contributes to the disposal of donated HM. The bacterial profile in HM is suspected to differ between term and preterm mothers, with HM from preterm mothers containing more bacteria. Thus, elucidation of the causes of bacterial growth in preterm and term HM may help to reduce the disposal of donated preterm HM. This study compared the bacterial profiles of HM between mothers of term infants and mothers of preterm infants. METHODS: This pilot study was conducted in the first Japanese HMB, which was initiated in 2017. This study analyzed 214 human milk samples (term: 75, preterm: 139) donated by 47 registered donors (term: 31, preterm: 16) from January to November 2021. Bacterial culture results in term and preterm HM were retrospectively reviewed in May 2022. Differences in total bacterial count and bacterial species count per batch were analyzed using the Mann-Whitney U test. Bacterial loads were analyzed using the Chi-square test or Fisher's exact test. RESULTS: The disposal rate did not significantly differ between term and preterm groups (p = 0.77), but the total amount of disposal was greater in the preterm group (p < 0.01). Coagulase-negative Staphylococci, Staphylococcus aureus, and Pseudomonas fluorescens were frequently found in both types of HM. Serratia liquefaciens (p < 0.001) and two other bacteria were present in term HM; a total of five types of bacteria, including Enterococcus faecalis and Enterobacter aerogenes (p < 0.001) were present in preterm HM. The median (interquartile range) total bacterial counts were 3,930 (435-23,365) colony-forming units (CFU)/mL for term HM and 26,700 (4,050-334,650) CFU/mL for preterm HM (p < 0.001). CONCLUSIONS: This study revealed that HM from preterm mothers had a higher total bacterial count and different types of bacteria than HM from term mothers. Additionally, preterm infants can receive nosocomial-infection-causing bacteria in the NICU through their mother's milk. Enhanced hygiene instructions for preterm mothers may reduce the disposal of valuable preterm human milk, along with the risk of HM pathogen transmission to infants in NICUs.

Protein and Immune Component Content of Donor Human Milk in Japan: Variation with Gestational and Postpartum Age.

Donor human milk (DHM) is the second-best nutrition for preterm infants when their own mother's milk is unavailable. The nutrient content of human milk is influenced by various factors, including gestational and postpartum age, but there are no data regarding DHM composition in Japan. The aim of this study was to determine the protein and immune component content of DHM in Japan and to elucidate the effects of gestational and postpartum age on nutrient composition. From September 2021 to May 2022, 134 DHM samples were collected from 92 mothers of preterm and term infants. Protein concentrations in preterm DHM (n = 41) and term DHM (n = 93) were analyzed using a Miris Human Milk Analyzer. The concentrations of secretory immunoglobulin A (sIgA) and lactoferrin, major immune components, were measured using enzyme-linked immunosorbent assays. Preterm DHM exhibited higher protein content than term DHM (1.2 g/dL and 1.0 g/dL, respectively, p < 0.001), whereas sIgA content was higher in term DHM than in preterm DHM (110 µg/mL and 68.4 µg/mL, respectively, p < 0.001). Gestational age was negatively correlated with protein levels and positively correlated with sIgA and lactoferrin levels. Furthermore, a negative correlation was found between postpartum week and protein, sIgA, and lactoferrin concentrations. Our data suggest that gestational and postpartum age affects protein, sIgA, and lactoferrin concentrations in DHM. These results indicate the importance of nutritional analysis for the appropriate use of DHM in preterm infants.

On-line statistical segmentation of a non-speech auditory stream in neonates as demonstrated by event-related brain potentials.

The ability to statistically segment a continuous auditory stream is one of the most important preparations for initiating language learning. Such ability is available to human infants at 8 months of age, as shown by a behavioral measurement. However, behavioral study alone cannot determine how early this ability is available. A recent study using measurements of event-related potential (ERP) revealed that neonates are able to detect statistical boundaries within auditory streams of speech syllables. Extending this line of research will allow us to better understand the cognitive preparation for language acquisition that is available to neonates. The aim of the present study was to examine the domain-generality of such statistical segmentation. Neonates were presented with nonlinguistic tone sequences composed of four tritone units, each consisting of three semitones extracted from one octave, for two 5-minute sessions. Only the first tone of each unit evoked a significant positivity in the frontal area during the second session, but not in the first session. This result suggests that the general ability to distinguish units in an auditory stream by statistical information is activated at birth and is probably innately prepared in humans.

Comparison of creamatocrit and protein concentration in each mammary lobe of the same breast: does the milk composition of each mammary lobe differ in the same breast?

OBJECTIVE: We sought to determine if different mammary lobes produce milk of varying composition. STUDY DESIGN: Seventeen mothers were enrolled in this study. Foremilk was obtained from three nipple openings on each breast. After the breastfeeding session, hindmilk was sampled in the same manner. We measured creamatocrit (CrCt) and analyzed the protein concentration. Data were analyzed with the paired t test and Wilcoxon signed-rank sum test where appropriate. Coefficient of variance (COV) was calculated to identify the variation of protein content among different mammary lobes. RESULTS: The fat and protein contents of the foremilk and hindmilk from each milk duct differed despite being expressed from the same breast. When we compared the CrCt values and protein content obtained from three ducts, a greater than 5% difference between the maximum and minimum value was observed in 64 out of 68 breasts (94%) for CrCt and in 61 out of 68 breasts (91%) for protein content. The mean COV of protein content in each breast was 13.2 +/- 8.0 (range, 1.2-45.3). CONCLUSIONS: These study results demonstrate that milk synthesis differs in each mammary lobe, even in the same breast. The degree of fullness in each mammary lobe seems to play the most important role in the fat content. The protein content in the milk from each mammary lobe is determined by other factors, presumably by the feedback inhibitor of lactation, accumulated in the corresponding mammary lobe.

The important role of deep attachment in the uniform drainage of breast milk from mammary lobe.

AIM: To determine if the degree of attachment affects uniformity in the drainage of breast milk from mammary lobe during breastfeeding. METHODS: Thirty-seven pairs of healthy breast-fed infants and mothers were the subjects. A total of 48 measurements were obtained. Foremilk was obtained from three nipple openings. After the breastfeeding session, hindmilk was sampled from the same three nipple openings and creamatocrit (CrCt) was measured. The difference in CrCt values of hindmilk, which corresponds to the degree of emptying of the lobe, and the difference in CrCt values between fore- and hindmilk samples (delta CrCt), which corresponds to the change in the degree of emptying among the lobe were calculated. RESULTS: The maximum difference in the CrCt value of hindmilk samples among nipple ducts was 7.0 +/- 4.1% in the shallow attachment (S) group (n = 23) and 2.9 +/- 1.2% in the deep attachment (D) group (n = 25) in the left breast and 5.4 +/- 2.2% in the S group (n = 21) and 3.6 +/- 1.9% in the D group (n = 27) in the right breast. The mean maximum difference in delta CrCt values among nipple ducts was 7.6 +/- 2.9% and 2.6 +/- 1.3% in the left and 5.8 +/- 2.3% and 3.4 +/- 1.4% in the right breast, in the S group and D group, respectively. These differences were significantly smaller in the D group than the S group (p < 0.01). CONCLUSION: The results revealed that deep attachment is helpful in draining milk from all mammary lobe uniformly, which may contribute to successful breastfeeding.

Differences in perception of the WHO International Code of Marketing of Breast Milk Substitutes between pediatricians and obstetricians in Japan.

BACKGROUND: The World Health Organization International Code of Marketing of Breast-Milk Substitutes (WHO Code) aims to protect and promote breastfeeding. Japan ratified the WHO Code in 1994, but most hospitals in Japan continue to receive free supplies of infant formula and distribute discharge packs to new mothers provided by infant formula companies. The aim of this study was to explore the knowledge and attitudes of pediatricians and obstetricians in Japan to the WHO Code. METHODS: A self-completion questionnaire was sent to 132 pediatricians in the 131 NICUs which belonged to the Neonatal Network of Japan, and to 96 chief obstetricians in the general hospitals in the Kanto area of Japan, in 2004. RESULTS: Responses were received from 68% of pediatricians and 64% of obstetricians. Sixty-six percent of pediatricians agreed that "Breastmilk is the best", compared to only 13% of obstetricians. Likewise, pediatricians were more likely to be familiar with the WHO Code (51%) than obstetricians (18%). CONCLUSION: In Japan, pediatricians and obstetricians, in general, have low levels of support for breastfeeding and low levels of familiarity with the WHO Code. To increase the breastfeeding rates in Japan, both pediatricians and obstetricians need increased knowledge about current infant feeding practices and increased awareness of international policies to promote breastfeeding.