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Peter E. Hartmann - One of the best experts on this subject based on the ideXlab platform.
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Milk ejection patterns remain consistent during the first and second lactations
American journal of human biology : the official journal of the Human Biology Council, 2017Co-Authors: Hazel Gardner, Danielle K. Prime, Ching Tat Lai, Peter E. Hartmann, Jacqueline C. Kent, Donna T. GeddesAbstract: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.
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Mitoulas et alJ Hum Lact 18(4), 2002 J Hum Lact 18(4), 2002Breast Milk Expression Effect of Vacuum Profile on Breast Milk Expression Using an Electric Breast Pump
2016Co-Authors: Leon R. Mitoulas, Ching Tat Lai, Michael Larsson, Lyle C. Gurrin, Peter E. HartmannAbstract:The authors compared milk expression using 5 experimental vacuum patterns and a commer-cially available vacuumpattern ranging in cycle times (20 to 78 cycles/min) and vacuumcurve dynamics in 30mothers using an experimental, software-controlled electric Breast Pump. The volume of milk removed over 5minutes differed (P =.0072) between patterns (range = 62.8 ± 6.6mL to 47.2 ± 5.1mL).However, therewas no difference in the percentage of availablemilk removed (range = 99.4 % ± 15.1 % to 70.6 % ± 8.6%). The rate of milk removal differed be-tween patterns at both the beginning (1minute) and end (1.5minutes) of the expression period (P <.05). Peak vacuum chosen differed between patterns (P =.0085) but was not related to ei-ther the volume or percentage of available milk expressed. Breastfeeding characteristics did not differ between poor and successful expressers. These results show that Breast milk expres-sion by an electric Breast Pump can be influenced by the vacuum pattern. J Hum Lact. 18(4): 353-360
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10.1177/0890334403252473 ARTICLE Kent et al Electric Breast Pump Response of Breasts to Different Stimulation Patterns of an Electric Breast Pump
2016Co-Authors: Michael Larsson, Peter E. HartmannAbstract:To test the effect on milk ejection, an electric Breast Pump was programmed to provide Pump-ing patterns with frequencies of 45 to 125 cycles/min and vacuums of –45 to –273 mm Hg. The time taken for milk ejection to occur (measured using ultrasound to detect a dilation of a lactiferous duct in the opposite Breast) in response to the current Medela electric Breast Pump pattern (45 cycles/min) was 147 ± 13 s. For patterns that more closely resemble the sucking frequency of an infant when it first attaches to the Breast, milk ejection occurred between 136 ± 12 and 104 ± 10 s, although this difference was not statistically significant. Milk ejection in re-sponse to Breastfeeding occurred after 56 ± 4 s. The applied vacuum affected the amount of milk that was removed up to 50 to 70 s after milk ejection but not the time for milk ejection.
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Investigation of Short-term Variations in Term Breast Milk Composition during Repeated Breast Expression Sessions
Journal of human lactation : official journal of International Lactation Consultant Association, 2013Co-Authors: Sadaf Khan, Danielle K. Prime, Anna R. Hepworth, Ching Tat Lai, Naomi Trengove, Peter E. HartmannAbstract: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 ...
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Effect of warm Breastshields on Breast milk Pumping.
Journal of human lactation : official journal of International Lactation Consultant Association, 2011Co-Authors: Jacqueline C. Kent, Anna R. Hepworth, Donna T. Geddes, Peter E. HartmannAbstract:The effect of using a warm Breastshield on the efficiency, effectiveness, and comfort of expressing milk with an electric Breast Pump was assessed. The authors tested a standard Breastshield at 25°C and a Breastshield warmed to 39°C on 25 mothers using their maximum comfortable vacuum or -125 mm Hg. Using a warm Breastshield effectively warmed the nipple and areola and, combined with maximum comfortable vacuum, decreased the time to remove 80% of the total milk yield and increased the percentage of available milk removed after 5 minutes of expression, with no change in the percentage of available milk removed after 15 minutes of expression compared with an ambient-temperature Breastshield. The data confirmed that use of the mother's maximum comfortable vacuum was more efficient than a vacuum of -125 mm Hg. Using a warm Breastshield with an electric Breast Pump was comfortable and improved the efficiency of milk removal.
Rocío Espinosa - One of the best experts on this subject based on the ideXlab platform.
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Whey protein/casein ratio and nonprotein nitrogen in preterm human milk during the first 10 days postpartum.
Journal of pediatric gastroenterology and nutrition, 1998Co-Authors: Vı́ctor Manuel Sánchez-hidalgo, Samuel Flores-huerta, Guadalupe Matute, Claudia Serrano, Bárbara Urquieta, Rocío EspinosaAbstract:Background: This study was designed to describe the longitudinal changes in the casein and whey fractions and the total and nonprotein nitrogen contents of preterm human milk for the first 10 days postpartum. Methods: Eleven mothers delivering at 30 to 34 weeks of gestation were studied, six throughout the first 10 days and five on the first postpartum day . Four milk samples were collected every day by expression of one Breast with an electric Breast Pump. Casein and whey protein were separated from the defatted milk by isoelectric precipitation in calcium chloride and by subsequent ultracentrifugation. The milk nitrogen content was determined before and after acid precipitation. Whey protein and casein were characterized by electrophoresis in polyacrylamide gel. Results: Total and protein nitrogen showed a sharp decrease during the first 3 postpartum days, whereas the nonprotein nitrogen did not change markedly (mean concentration. 0.58 mg.ml -1 ). Casein content expressed as nitrogen in preterm human milk was 0.35 mg.ml -1 between days 3 and 5 and 0.60 mg.ml -1 between days 6 and 10. The whey protein-casein ratio before day 2, was 100:0, at day 3, 86:14, at day 5, 76:24. and at day 1(), 70:30. Three days after delivery, casein levels rose progressively, increasing markedly alter day 6. Conclusions: These findings suggest that delivering before term affects neither casein production nor its chemical characteristics.
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whey protein casein ratio and nonprotein nitrogen in preterm human milk during the first 10 days postpartum
Journal of Pediatric Gastroenterology and Nutrition, 1998Co-Authors: Victor Manuel Sanchezhidalgo, Guadalupe Matute, Claudia Serrano, Bárbara Urquieta, Samuel Floreshuerta, Rocío EspinosaAbstract:Background: This study was designed to describe the longitudinal changes in the casein and whey fractions and the total and nonprotein nitrogen contents of preterm human milk for the first 10 days postpartum. Methods: Eleven mothers delivering at 30 to 34 weeks of gestation were studied, six throughout the first 10 days and five on the first postpartum day . Four milk samples were collected every day by expression of one Breast with an electric Breast Pump. Casein and whey protein were separated from the defatted milk by isoelectric precipitation in calcium chloride and by subsequent ultracentrifugation. The milk nitrogen content was determined before and after acid precipitation. Whey protein and casein were characterized by electrophoresis in polyacrylamide gel. Results: Total and protein nitrogen showed a sharp decrease during the first 3 postpartum days, whereas the nonprotein nitrogen did not change markedly (mean concentration. 0.58 mg.ml -1 ). Casein content expressed as nitrogen in preterm human milk was 0.35 mg.ml -1 between days 3 and 5 and 0.60 mg.ml -1 between days 6 and 10. The whey protein-casein ratio before day 2, was 100:0, at day 3, 86:14, at day 5, 76:24. and at day 1(), 70:30. Three days after delivery, casein levels rose progressively, increasing markedly alter day 6. Conclusions: These findings suggest that delivering before term affects neither casein production nor its chemical characteristics.
Claudia Serrano - One of the best experts on this subject based on the ideXlab platform.
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Whey protein/casein ratio and nonprotein nitrogen in preterm human milk during the first 10 days postpartum.
Journal of pediatric gastroenterology and nutrition, 1998Co-Authors: Vı́ctor Manuel Sánchez-hidalgo, Samuel Flores-huerta, Guadalupe Matute, Claudia Serrano, Bárbara Urquieta, Rocío EspinosaAbstract:Background: This study was designed to describe the longitudinal changes in the casein and whey fractions and the total and nonprotein nitrogen contents of preterm human milk for the first 10 days postpartum. Methods: Eleven mothers delivering at 30 to 34 weeks of gestation were studied, six throughout the first 10 days and five on the first postpartum day . Four milk samples were collected every day by expression of one Breast with an electric Breast Pump. Casein and whey protein were separated from the defatted milk by isoelectric precipitation in calcium chloride and by subsequent ultracentrifugation. The milk nitrogen content was determined before and after acid precipitation. Whey protein and casein were characterized by electrophoresis in polyacrylamide gel. Results: Total and protein nitrogen showed a sharp decrease during the first 3 postpartum days, whereas the nonprotein nitrogen did not change markedly (mean concentration. 0.58 mg.ml -1 ). Casein content expressed as nitrogen in preterm human milk was 0.35 mg.ml -1 between days 3 and 5 and 0.60 mg.ml -1 between days 6 and 10. The whey protein-casein ratio before day 2, was 100:0, at day 3, 86:14, at day 5, 76:24. and at day 1(), 70:30. Three days after delivery, casein levels rose progressively, increasing markedly alter day 6. Conclusions: These findings suggest that delivering before term affects neither casein production nor its chemical characteristics.
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whey protein casein ratio and nonprotein nitrogen in preterm human milk during the first 10 days postpartum
Journal of Pediatric Gastroenterology and Nutrition, 1998Co-Authors: Victor Manuel Sanchezhidalgo, Guadalupe Matute, Claudia Serrano, Bárbara Urquieta, Samuel Floreshuerta, Rocío EspinosaAbstract:Background: This study was designed to describe the longitudinal changes in the casein and whey fractions and the total and nonprotein nitrogen contents of preterm human milk for the first 10 days postpartum. Methods: Eleven mothers delivering at 30 to 34 weeks of gestation were studied, six throughout the first 10 days and five on the first postpartum day . Four milk samples were collected every day by expression of one Breast with an electric Breast Pump. Casein and whey protein were separated from the defatted milk by isoelectric precipitation in calcium chloride and by subsequent ultracentrifugation. The milk nitrogen content was determined before and after acid precipitation. Whey protein and casein were characterized by electrophoresis in polyacrylamide gel. Results: Total and protein nitrogen showed a sharp decrease during the first 3 postpartum days, whereas the nonprotein nitrogen did not change markedly (mean concentration. 0.58 mg.ml -1 ). Casein content expressed as nitrogen in preterm human milk was 0.35 mg.ml -1 between days 3 and 5 and 0.60 mg.ml -1 between days 6 and 10. The whey protein-casein ratio before day 2, was 100:0, at day 3, 86:14, at day 5, 76:24. and at day 1(), 70:30. Three days after delivery, casein levels rose progressively, increasing markedly alter day 6. Conclusions: These findings suggest that delivering before term affects neither casein production nor its chemical characteristics.
Guadalupe Matute - One of the best experts on this subject based on the ideXlab platform.
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Whey protein/casein ratio and nonprotein nitrogen in preterm human milk during the first 10 days postpartum.
Journal of pediatric gastroenterology and nutrition, 1998Co-Authors: Vı́ctor Manuel Sánchez-hidalgo, Samuel Flores-huerta, Guadalupe Matute, Claudia Serrano, Bárbara Urquieta, Rocío EspinosaAbstract:Background: This study was designed to describe the longitudinal changes in the casein and whey fractions and the total and nonprotein nitrogen contents of preterm human milk for the first 10 days postpartum. Methods: Eleven mothers delivering at 30 to 34 weeks of gestation were studied, six throughout the first 10 days and five on the first postpartum day . Four milk samples were collected every day by expression of one Breast with an electric Breast Pump. Casein and whey protein were separated from the defatted milk by isoelectric precipitation in calcium chloride and by subsequent ultracentrifugation. The milk nitrogen content was determined before and after acid precipitation. Whey protein and casein were characterized by electrophoresis in polyacrylamide gel. Results: Total and protein nitrogen showed a sharp decrease during the first 3 postpartum days, whereas the nonprotein nitrogen did not change markedly (mean concentration. 0.58 mg.ml -1 ). Casein content expressed as nitrogen in preterm human milk was 0.35 mg.ml -1 between days 3 and 5 and 0.60 mg.ml -1 between days 6 and 10. The whey protein-casein ratio before day 2, was 100:0, at day 3, 86:14, at day 5, 76:24. and at day 1(), 70:30. Three days after delivery, casein levels rose progressively, increasing markedly alter day 6. Conclusions: These findings suggest that delivering before term affects neither casein production nor its chemical characteristics.
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whey protein casein ratio and nonprotein nitrogen in preterm human milk during the first 10 days postpartum
Journal of Pediatric Gastroenterology and Nutrition, 1998Co-Authors: Victor Manuel Sanchezhidalgo, Guadalupe Matute, Claudia Serrano, Bárbara Urquieta, Samuel Floreshuerta, Rocío EspinosaAbstract:Background: This study was designed to describe the longitudinal changes in the casein and whey fractions and the total and nonprotein nitrogen contents of preterm human milk for the first 10 days postpartum. Methods: Eleven mothers delivering at 30 to 34 weeks of gestation were studied, six throughout the first 10 days and five on the first postpartum day . Four milk samples were collected every day by expression of one Breast with an electric Breast Pump. Casein and whey protein were separated from the defatted milk by isoelectric precipitation in calcium chloride and by subsequent ultracentrifugation. The milk nitrogen content was determined before and after acid precipitation. Whey protein and casein were characterized by electrophoresis in polyacrylamide gel. Results: Total and protein nitrogen showed a sharp decrease during the first 3 postpartum days, whereas the nonprotein nitrogen did not change markedly (mean concentration. 0.58 mg.ml -1 ). Casein content expressed as nitrogen in preterm human milk was 0.35 mg.ml -1 between days 3 and 5 and 0.60 mg.ml -1 between days 6 and 10. The whey protein-casein ratio before day 2, was 100:0, at day 3, 86:14, at day 5, 76:24. and at day 1(), 70:30. Three days after delivery, casein levels rose progressively, increasing markedly alter day 6. Conclusions: These findings suggest that delivering before term affects neither casein production nor its chemical characteristics.
Bárbara Urquieta - One of the best experts on this subject based on the ideXlab platform.
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Whey protein/casein ratio and nonprotein nitrogen in preterm human milk during the first 10 days postpartum.
Journal of pediatric gastroenterology and nutrition, 1998Co-Authors: Vı́ctor Manuel Sánchez-hidalgo, Samuel Flores-huerta, Guadalupe Matute, Claudia Serrano, Bárbara Urquieta, Rocío EspinosaAbstract:Background: This study was designed to describe the longitudinal changes in the casein and whey fractions and the total and nonprotein nitrogen contents of preterm human milk for the first 10 days postpartum. Methods: Eleven mothers delivering at 30 to 34 weeks of gestation were studied, six throughout the first 10 days and five on the first postpartum day . Four milk samples were collected every day by expression of one Breast with an electric Breast Pump. Casein and whey protein were separated from the defatted milk by isoelectric precipitation in calcium chloride and by subsequent ultracentrifugation. The milk nitrogen content was determined before and after acid precipitation. Whey protein and casein were characterized by electrophoresis in polyacrylamide gel. Results: Total and protein nitrogen showed a sharp decrease during the first 3 postpartum days, whereas the nonprotein nitrogen did not change markedly (mean concentration. 0.58 mg.ml -1 ). Casein content expressed as nitrogen in preterm human milk was 0.35 mg.ml -1 between days 3 and 5 and 0.60 mg.ml -1 between days 6 and 10. The whey protein-casein ratio before day 2, was 100:0, at day 3, 86:14, at day 5, 76:24. and at day 1(), 70:30. Three days after delivery, casein levels rose progressively, increasing markedly alter day 6. Conclusions: These findings suggest that delivering before term affects neither casein production nor its chemical characteristics.
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whey protein casein ratio and nonprotein nitrogen in preterm human milk during the first 10 days postpartum
Journal of Pediatric Gastroenterology and Nutrition, 1998Co-Authors: Victor Manuel Sanchezhidalgo, Guadalupe Matute, Claudia Serrano, Bárbara Urquieta, Samuel Floreshuerta, Rocío EspinosaAbstract:Background: This study was designed to describe the longitudinal changes in the casein and whey fractions and the total and nonprotein nitrogen contents of preterm human milk for the first 10 days postpartum. Methods: Eleven mothers delivering at 30 to 34 weeks of gestation were studied, six throughout the first 10 days and five on the first postpartum day . Four milk samples were collected every day by expression of one Breast with an electric Breast Pump. Casein and whey protein were separated from the defatted milk by isoelectric precipitation in calcium chloride and by subsequent ultracentrifugation. The milk nitrogen content was determined before and after acid precipitation. Whey protein and casein were characterized by electrophoresis in polyacrylamide gel. Results: Total and protein nitrogen showed a sharp decrease during the first 3 postpartum days, whereas the nonprotein nitrogen did not change markedly (mean concentration. 0.58 mg.ml -1 ). Casein content expressed as nitrogen in preterm human milk was 0.35 mg.ml -1 between days 3 and 5 and 0.60 mg.ml -1 between days 6 and 10. The whey protein-casein ratio before day 2, was 100:0, at day 3, 86:14, at day 5, 76:24. and at day 1(), 70:30. Three days after delivery, casein levels rose progressively, increasing markedly alter day 6. Conclusions: These findings suggest that delivering before term affects neither casein production nor its chemical characteristics.