title: Changes in preterm breast milk nutrient content in the first month.
abstract: BACKGROUND
  The primary aim of the study was to investigate the changes in composition of breast milk from mothers with preterm infants (gestation age < 35 weeks) during the first 4-6 weeks of lactation.
  
  
  METHODS
  Breast milk from 17 mothers who had delivered preterm infants was collected longitudinally for 4-6 weeks. Breast milk from 15 mothers of full-term infants was also collected at the 1(st) week and 4(th) week. Fat, protein, lactose, energy, minerals (calcium and phosphate), and immune components [secretory immunoglobulin A (IgA), leptin, lysozyme, and lactoferrin] content were measured weekly in each participant. A mid-infrared human milk analyzer was used to measure the protein, fat, and lactose contents. Calcium and phosphate components were checked via spectrophotometry. The concentrations of major immune components (secretory IgA, lactoferrin, lysozyme, and leptin) were quantified using enzyme-linked immunosorbent assay kits.
  
  
  RESULTS
  Eighty samples from 17 preterm mothers were collected. The mean gestational age was 29.88 ± 2.39 weeks. There were significant changes in nutrient components during these periods, with increases in lactose (p < 0.001), lipid (p = 0.001), calorie (p = 0.012), and phosphate (p = 0.022) concentration and decreases in protein (p < 0.001) and secretory IgA (p < 0.001) concentration. There were no differences in calcium (p = 0.919), lactoferrin (p = 0.841), leptin (p = 0.092), and lysozyme (p = 0.561) levels. Furthermore, there were no significant differences in most components of breast milk between full-term and preterm mothers.
  
  
  CONCLUSIONS
  The longitudinal study revealed significant changes in macronutrient contents and secretory IgA concentration in preterm milk over the 4-6 week period, which is compatible with the results of previous studies. The quantification of phosphate in preterm breast milk was lower than the normal range, suggesting that close monitoring of body bone mass may be indicated. More studies are warranted to evaluate the clinical significance of alterations of major milk components during the postnatal stage.
authors.affiliation: Department of Pediatrics, Chiayi Branch, Taichung Veterans General Hospital, Chiayi, Taiwan.
authors.forename: Ya-Chi
authors.initials: YC
authors.lastname: Hsu
authors.affiliation: Division of Neonatology, Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan; Department of Pediatrics and Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan; School of Medicine, China Medical University, Taichung, Taiwan. Electronic address: joy1477@gmail.com.
authors.forename: Chao-Huei
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Division of Neonatology, Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan; Department of Pediatrics and Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Ming-Chih
authors.initials: MC
authors.lastname: Lin
authors.affiliation: Division of Neonatology, Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Chi-Ren
authors.initials: CR
authors.lastname: Tsai
authors.affiliation: Pathology and Laboratory Medicine Department, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Jiin-Tsae
authors.initials: JT
authors.lastname: Liang
authors.affiliation: Division of Neonatology, Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Teh-Ming
authors.initials: TM
authors.lastname: Wang
mesh_terms: D000328:Adult; D005260:Female; D005865:Gestational Age; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000032:analysis; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007785:Lactose / Q000032:analysis; D008137:Longitudinal Studies; D008895:Milk, Human / Q000737:chemistry*
chemical_list: D007071:Immunoglobulin A, Secretory; D007785:Lactose
keywords: calcium; human milk; immune component; macronutrient; phosphate; preterm infant