Bioimpedance spectroscopy in the infant: effect of milk intake and extracellular fluid reservoirs on resistance measurements in term breastfed infants.

BACKGROUND/OBJECTIVES: Bioimpedance spectroscopy is an accurate non-invasive method for measuring body composition in adults, but in infants it requires further testing and validation. Of the few studies of bioimpedance conducted in infants, none have comprehensively investigated the effect of milk intake volume. This study assessed the effect of the milk intake, feed duration and the volume of the infant's stomach and bladder on the resistance values pre-/post-feed to establish the feasibility of using these values interchangeably during data collection. SUBJECTS/METHODS: Forty-eight breastfeeding infants were measured at 2, 5, 9 and/or 12 months (n=62 sessions) within 1-2 min before the start and after the end of breastfeed. Median (IQR) time between measurements was 24 (20.0-30.0) min. Resistance measurements at 0 and 50 kHz, and infinite frequency (R0, R50 and Rinf) and resistance of intracellular water (Ricw) were analysed with customised infant settings. Milk intake was measured by test weights. Free-water volumes and free-water change were determined from stomach and bladder volumes calculated from ultrasound images. RESULTS: Small pre-to-post-feed changes (median (IQR): R0 -3.7 (-14.8, 14.3); R50 0.3 (-10.4, 15.0); Rinf 2.8 (-13.3, 35.5); Ricw 20.8 (-98.1, 290.9)) were not significantly different from zero (R0: P=0.92; R50: P=0.48; Rinf: P=0.32; Ricw: P=0.097). No significant effect of milk intake or free-water change was detected. CONCLUSIONS: The lack of consistent change in resistance across a breastfeed provides flexibility in the timing of measurements of infants in the research setting, such that typically pre- and post-feed measures of resistance can be used interchangeably.

Analysis of insulin in human breast milk in mothers with type 1 and type 2 diabetes mellitus.

Despite the important role that insulin plays in the human body, very little is known about its presence in human milk. Levels rapidly decrease during the first few days of lactation and then, unlike other serum proteins of similar size, achieve comparable levels to those in serum. Despite this, current guides for medical treatment suggest that insulin does not pass into milk, raising the question of where the insulin in milk originates. Five mothers without diabetes, 4 mothers with type 1, and 5 mothers with type 2 diabetes collected milk samples over a 24-hour period. Samples were analysed for total and endogenous insulin content and for c-peptide content. All of the insulin present in the milk of type 1 mothers was artificial, and c-peptide levels were 100x lower than in serum. This demonstrates that insulin is transported into human milk at comparable concentration to serum, suggesting an active transport mechanism. The role of insulin in milk is yet to be determined; however, there are a number of potential implications for the infant of the presence of artificial insulins in milk.

Combining hand techniques with electric pumping increases the caloric content of milk in mothers of preterm infants.

OBJECTIVE: We previously reported that preterm mothers' milk production can exceed levels of term mothers by using early hand expression and hands-on pumping (HOP) with the highest production (955 ml per day) in frequent users of hand expression. In this study, we compared milk composition between mothers stratified by early hand expression frequency. STUDY DESIGN: A total of 67 mothers of infants <31 weeks gestation were instructed on hand expression and HOP. Subjects submitted expression records and 1-ml samples from each pumping session over 24 h once weekly for 8 weeks. RESULT: 78% (52/67) of mothers completed the study. But for Week 1, no compositional differences (despite production differences) were noted between the three groups. Protein and lactose tracked reported norms, but fat and energy of mature milk (Weeks 2-8) exceeded norms, 62.5 g l(-1) per fat and 892.7 cal l(-1) (26.4 cal oz(-1)), respectively. CONCLUSION: Mothers combining manual techniques with pumping express high levels of fat-rich, calorie-dense milk, unrelated to production differences.

Estimation of infant dose and exposure to pethidine and norpethidine via breast milk following patient-controlled epidural pethidine for analgesia post caesarean delivery.

BACKGROUND: There is no information about the distribution of pethidine into breast milk and/or exposure of the breastfed infant during pethidine patient-controlled epidural analgesia after caesarean delivery. METHODS: We conducted an observational study among 20 women. The mean (95% confidence interval) pethidine dose administered was 670 (346-818) mg over 41 (35-46) h. Maternal plasma and milk and neonatal plasma were collected near the time of pethidine cessation and 6h later. Absolute and relative infant doses via milk and infant exposure were calculated. Infant behaviour was assessed using the Neurologic and Adaptive Capacity Score. RESULTS: At first and second sampling times, mean absolute infant doses for pethidine were 20 (14-27) µg/kg/day and 10 (7-13) µg/kg/day, while mean relative infant doses were 0.7 (0.1-1.4)% and 0.3 (0.1-0.5)% respectively. Similar values for norpethidine (expressed as pethidine equivalents) were 21 (16-26) µg/kg/day and 22 (12-32) µg/kg/day; and 0.7 (0.3-1)% and 0.6 (0.2-1)% respectively. Mean pethidine and norpethidine concentrations in neonatal plasma were 3 (0-6.1) µg/L and 0.6 (0.2-1) µg/L. Compared with a time-matched maternal sample, the infant's exposure was 1.4 (0.2-2.8)% for pethidine and 0.4 (0.2-0.6)% for norpethidine. The mean (95% confidence interval) neurologic and adaptive capacity score was 33.6 (32.2-34.9). CONCLUSION: The combined absolute infant dose of pethidine and norpethidine received via milk was 1.8% of the neonatal therapeutic dose and the combined relative infant dose was below the 10% recommended safety level. Breastfed infants are at low risk of drug exposure when mothers self-administer epidural pethidine after caesarean delivery.

Recurrent blocked duct(s) in a mother with immunoglobulin A deficiency.

Abstract Secretory immunoglobulin A (sIgA) is the dominant immunoglobulin in human milk, and apart from the obvious contribution it makes towards the protection of the infant, sIgA may also form an important part of the defense of the mammary gland. This report involves a mother (M8) who participated in a research study investigating the relationships between symptoms and changes in the physiology of the lactating breast during mastitis. Breastmilk samples were collected on Days 14, 30, 60, and 90 postpartum, to establish the normal reference range of biochemical markers, and during periods of breast inflammation. M8 experienced seven episodes of blocked duct(s) during the first 19 weeks, five of which occurred within the 90-day reference sample collection period. On analysis, it was found there was no detectable sIgA present in her milk samples. Medical referral and further testing resulted in a diagnosis of selective IgA deficiency, of which the mother had not been previously aware. M8 showed little variation in her milk composition even when suffering with blocked duct(s), although there was an increase in the concentration of lactoferrin in both breasts at reference collection days 14-90. Lactoferrin concentration was also unusually high at Day 14 (15 g/L) in the left breast and continued to be increased in this breast until Day 60. The absence of sIgA in this mother's breastmilk may have been a contributing factor in her experiencing recurrent blocked ducts.

Best practice guidelines for the operation of a donor human milk bank in an Australian NICU.

Until the establishment of the PREM Bank (Perron Rotary Express Milk Bank) donor human milk banking had not occurred in Australia for the past 20 years. In re-establishing donor human milk banking in Australia, the focus of the PREM Bank has been to develop a formal and consistent approach to safety and quality in processing during the operation of the human milk bank. There is currently no existing legislation in Australia that specifically regulates the operation of donor human milk banks. For this reason the PREM Bank has utilised existing and internationally recognised management practices for managing hazards during food production. These tools (specifically HACCP) have been used to guide the development of Standard Operating Procedures and Good Manufacturing Practice for the screening of donors and processing of donor human milk. Donor screening procedures are consistent with those recommended by other human milk banks operating internationally, and also consistent with the requirements for blood and tissue donation in Australia. Controlled documentation and record keep requirements have also been developed that allow complete traceability from individual donation to individual feed dispensed to recipient and maintain a record of all processing and storage conditions. These operational requirements have been developed to reduce any risk associated with feeding pasteurised donor human milk to hospitalised preterm or ill infants to acceptable levels.

Analysis of feeding behavior with direct linear transformation.

AIM: The sucking pattern of term infants is composed of a rhythmic alteration of expression and suction movements. The aim is to evaluate if direct linear transformation (DLT) method could be used for the assessment of infant feeding. SUBJECT AND METHODS: A total of 10 gnormalh infants and two infants with neurological disorders were studied using DLT procedures and expression/suction pressure recordings. Feeding pattern of seven gnormalh infants were evaluated simultaneously recording DLT and pressures. The other infants were tested non-simultaneously. We placed markers on the lateral angle of the eye, tip of the jaw, and throat. The faces of infants while sucking were recorded in profile. The jaw and throat movements were calculated using the DLT procedure. Regression analysis was implemented to investigate the relationship between suction and expression pressures and eye-jaw and eye-throat movement. All regression analyses investigated univariate relationships and adjusted for other covariates. RESULTS: Ten gnormalh infants demonstrated higher suction pressure than expression pressure, and their throat movements were larger than jaw movements. Two infants with neurological problems did not generate suction pressure and demonstrated larger movements in their jaw than throat. The simultaneous measurement (n=7) showed a significant correlation, not only between eye-jaw distance and the expression pressure, but also between eye-throat distance and suction pressure. The change in the eye-jaw distance was smaller than the changes in the eye-throat distance in gnormalh infants (p<0.001). CONCLUSIONS: The DLT method can be used to evaluate feeding performance without any special device.

Anatomy of the lactating human breast redefined with ultrasound imaging.

The aim of this study was to use ultrasound imaging to re-investigate the anatomy of the lactating breast. The breasts of 21 fully lactating women (1-6 months post partum) were scanned using an ACUSON XP10 (5-10 MHz linear array probe). The number of main ducts was measured, ductal morphology was determined, and the distribution of glandular and adipose tissue was recorded. Milk ducts appeared as hypoechoic tubular structures with echogenic walls that often contained echoes. Ducts were easily compressed and did not display typical sinuses. All ducts branched within the areolar radius, the first branch occurring 8.0 +/- 5.5 mm from the nipple. Duct diameter was 1.9 +/- 0.6 mm, 2.0 +/- 90.7 mm and the number of main ducts was 9.6 +/- 2.9, 9.2 +/- 2.9, for left and right breast, respectively. Milk ducts are superficial, easily compressible and echoes within the duct represent fat globules in breastmilk. The low number and size of the ducts, the rapid branching under the areola and the absence of sinuses suggest that ducts transport breastmilk, rather than store it. The distribution of adipose and glandular tissue showed wide variation between women but not between breasts within women. The proportion of glandular and fat tissue and the number and size of ducts were not related to milk production. This study highlights inconsistencies in anatomical literature that impact on breast physiology, breastfeeding management and ultrasound assessment.

The effect of supplementation with fish oil during pregnancy on breast milk immunoglobulin A, soluble CD14, cytokine levels and fatty acid composition.

BACKGROUND: Breast milk contains many immunomodulatory factors (soluble CD14 (sCD14), IgA and cytokines) with the potential to influence infant immune development. OBJECTIVE: To determine if changes in breast milk omega-3 polyunsaturated fatty acid (n-3 PUFA) composition as a result of maternal dietary fish oil supplementation during pregnancy can modify levels of these immunological parameters in breast milk. METHOD: In a randomized controlled trial, 83 atopic women received either 4 g fish oil capsules (containing 3.7 g n-3 PUFA) (n = 40) or 4 g olive oil capsules (n = 43) from 20 weeks gestation until delivery. Breast milk was collected 3 days post-partum and fatty acids were analysed by gas liquid chromatography and IgA, sCD14 and cytokines (IL-5, IL-6, IL-10, TNF-alpha and IFN-gamma) were quantitated by ELISA or time resolved fluorescence (TRF). RESULTS: Omega-3 docosahexaenoic acid (DHA; 22:6n-3) and eicosapentaenoic acid (EPA; 20:5n-3) levels were significantly higher (P < 0.001) in breast milk from women supplemented with fish oil (n = 33, DHA mean 1.15%, SD 0.47% and EPA mean 0.16%, SD 0.07%) than in samples from the control group (n = 40, DHA mean 0.50%, SD 0.17% and EPA mean 0.05%, SD 0.02%). Breast milk arachidonic acid (AA; 20:4n-6) levels were significantly lower (P = 0.045) in the fish oil group (mean 0.55%, SD 0.12%) compared with the control group (mean 0.61%, SD 0.14%). Breast milk IgA was positively correlated with DHA (P = 0.046) and 22:5n-3 (P = 0.003), but inversely correlated with linoleic acid (LA; 18:2n-6) (P=0.034). Levels of sCD14 were also positively correlated with 22:5n-3 (P=0.009). Cytokines involved in IgA synthesis (IL-10 and IL-6) were also significantly correlated with both IgA and n-3 PUFA levels, although there were no differences in the levels of breast milk IgA, sCD14 or cytokines between study groups. CONCLUSION: Supplementation with fish oil during pregnancy significantly alters early post-partum breast milk fatty acid composition. omega-3 PUFA levels were positively associated with IgA and sCD14 levels, suggesting a relationship between fatty acid status and mucosal immune function.

Computerized breast measurement from conception to weaning: clinical implications.

The CBM system has enabled our laboratory to measure breast growth and demonstrate the importance of the short-term local control of milk synthesis in lactating women. Although the specific mechanism by which the short-term control of milk synthesis occurs has yet to be fully understood, it is now apparent that the interaction between storage capacity, degree of fullness, and frequency of milk removal plays a significant role. These factors demonstrate that the breastfeeding mother can take comfort in the individuality of her breast development and feeding pattern, which is uniquely adapted to suit the physiology of her breasts and the developmental requirements of her infant.

Breast growth and the urinary excretion of lactose during human pregnancy and early lactation: endocrine relationships.

Breast volume and morphology of eight subjects were measured before conception and at intervals throughout pregnancy until 1 month of lactation. Breast volume before conception ranged from 293 to 964 ml. At the end of pregnancy the volume of breast tissue had increased by 145+/-19 ml (mean+/-S.E.M., n = 13 breasts, range 12-227 ml) with a further increase to 211+/-16 ml (n = 12 breasts, range 129-320 ml) by 1 month of lactation. Urinary excretion of lactose increased at 22 weeks of pregnancy, signalling the capacity of the breast to synthesize lactose at this time. During pregnancy, both the change in breast volume and the change in cross-sectional area of the areola were related to the concentration of human placental lactogen in the plasma. The growth of the nipple and the rate of excretion of lactose were related to the concentration of prolactin in the plasma. During the first 3 days after birth, the rate of excretion of lactose was related to the rate of excretion of progesterone. There was no relationship between the growth of the breast during pregnancy and the amount of milk produced at 1 month of lactation.

Breast volume and milk production during extended lactation in women.

Quantitative measurements were made of relative breast volume and milk production from 1 month of lactation until 3 months after weaning, and the storage capacity of the breasts was calculated. The increase in breast tissue volume from before conception until 1 month of lactation was maintained for the first 6 months of lactation (means+/-S.E.M.) (190.3+/-13.1 ml, number of breasts, nb = 46). During this period of exclusive breast-feeding, 24 h milk production from each breast remained relatively constant (453.6+/-201 g, nb = 48), and storage capacity was 209.9+/-11.0 ml (nb = 46). After 6 months, breast volume, milk production and storage capacity all decreased. There was a relationship between 24 h milk production and the storage capacity of the breasts, and these both appeared to be responding to infant demand for milk. At 15 months of lactation, the 24 h milk production of each breast was substantial (208.0+/-56.7 g, nb = 6), even though the breasts had returned to preconception size. This was associated with an apparent increased efficiency of the breast (milk production per unit breast tissue) after 6 months, which may have been due to redistribution of tissues within the breast. The possible causes of the decrease in breast volume are discussed.