Official reprint from UpToDate®
www.uptodate.com ©2017 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

Parenteral nutrition in premature infants

Richard J Schanler, MD
Section Editor
Steven A Abrams, MD
Deputy Editor
Alison G Hoppin, MD


The nutritional needs of premature infants are usually dependent upon parenteral nutrition (PN) during early postnatal life, especially for very low birth weight (VLBW) infants (birth weight of less than 1500 g). In these infants, full enteral feedings are generally delayed because of the severity of medical problems associated with prematurity, such as immature lung function (which often requires endotracheal intubation and mechanical ventilation), hypothermia, infections, and hypotension. In addition, early enteral feeds are also delayed because of concerns that aggressive feeding may lead to complications, such as feeding intolerance or necrotizing enterocolitis. As a result, the nutritional requirements of VLBW infants are rarely met by enteral feeds in the first two weeks after birth [1]. (See "Short-term complications of the preterm infant".)

PN (sometimes referred to as hyperalimentation) in the premature infant, including its composition, will be reviewed here. The approach to enteral nutrition in premature infants is discussed separately. (See "Approach to enteral nutrition in the premature infant".)


General goals — Because adequate enteral nutrition cannot be established in most very low birth weight (VLBW) infants in their early weeks, PN is initiated to correct in-utero growth restriction and to prevent subsequent growth faltering. More mature, and larger, premature infants may not require PN, because these infants usually tolerate early enteral nutrition. (See "Growth management in preterm infants".)

PN for the premature infant includes the following:

Adequate calories for energy expenditure and growth

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:

Subscribers log in here

Literature review current through: Nov 2017. | This topic last updated: Jul 20, 2017.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2017 UpToDate, Inc.
  1. Berry MA, Conrod H, Usher RH. Growth of very premature infants fed intravenous hyperalimentation and calcium-supplemented formula. Pediatrics 1997; 100:647.
  2. Embleton NE, Pang N, Cooke RJ. Postnatal malnutrition and growth retardation: an inevitable consequence of current recommendations in preterm infants? Pediatrics 2001; 107:270.
  3. Cazacu A, Fraley JK, Schanler RJ. We are inadequately nourishing healthy low birth weight infants. Pediatr Res 2001; 49:343A.
  4. Ehrenkranz RA. Early, aggressive nutritional management for very low birth weight infants: what is the evidence? Semin Perinatol 2007; 31:48.
  5. Moyses HE, Johnson MJ, Leaf AA, Cornelius VR. Early parenteral nutrition and growth outcomes in preterm infants: a systematic review and meta-analysis. Am J Clin Nutr 2013; 97:816.
  6. Christmann V, Visser R, Engelkes M, et al. The enigma to achieve normal postnatal growth in preterm infants--using parenteral or enteral nutrition? Acta Paediatr 2013; 102:471.
  7. Wilson DC, Cairns P, Halliday HL, et al. Randomised controlled trial of an aggressive nutritional regimen in sick very low birthweight infants. Arch Dis Child Fetal Neonatal Ed 1997; 77:F4.
  8. Ehrenkranz RA, Das A, Wrage LA, et al. Early nutrition mediates the influence of severity of illness on extremely LBW infants. Pediatr Res 2011; 69:522.
  9. Stephens BE, Walden RV, Gargus RA, et al. First-week protein and energy intakes are associated with 18-month developmental outcomes in extremely low birth weight infants. Pediatrics 2009; 123:1337.
  10. Hay WW Jr, Lucas A, Heird WC, et al. Workshop summary: nutrition of the extremely low birth weight infant. Pediatrics 1999; 104:1360.
  11. Sinclair JC. Metabolic rate and body size of the newborn. Clin Obstet Gynecol 1971; 14:840.
  12. Sinclair JC. Energy balance of the newborn. In: Temperature Regulation and Energy Metabolism in the Newborn, Sinclair JC (Ed), Grune & Stratton, New York 1978. p.187.
  13. Bresson JL, Bader B, Rocchiccioli F, et al. Protein-metabolism kinetics and energy-substrate utilization in infants fed parenteral solutions with different glucose-fat ratios. Am J Clin Nutr 1991; 54:370.
  14. Piedboeuf B, Chessex P, Hazan J, et al. Total parenteral nutrition in the newborn infant: energy substrates and respiratory gas exchange. J Pediatr 1991; 118:97.
  15. Salas-Salvadó J, Molina J, Figueras J, et al. Effect of the quality of infused energy on substrate utilization in the newborn receiving total parenteral nutrition. Pediatr Res 1993; 33:112.
  16. Stensvold HJ, Strommen K, Lang AM, et al. Early Enhanced Parenteral Nutrition, Hyperglycemia, and Death Among Extremely Low-Birth-Weight Infants. JAMA Pediatr 2015; 169:1003.
  17. Thureen PJ, Melara D, Fennessey PV, Hay WW Jr. Effect of low versus high intravenous amino acid intake on very low birth weight infants in the early neonatal period. Pediatr Res 2003; 53:24.
  18. Sunehag AL, Haymond MW, Schanler RJ, et al. Gluconeogenesis in very low birth weight infants receiving total parenteral nutrition. Diabetes 1999; 48:791.
  19. Zlotkin SH, Bryan MH, Anderson GH. Intravenous nitrogen and energy intakes required to duplicate in utero nitrogen accretion in prematurely born human infants. J Pediatr 1981; 99:115.
  20. Malloy MH, Rassin DK, Richardson CJ. Total parenteral nutrition in sick preterm infants: effects of cysteine supplementation with nitrogen intakes of 240 and 400 mg/kg/day. J Pediatr Gastroenterol Nutr 1984; 3:239.
  21. Mitton SG. Amino acids and lipid in total parenteral nutrition for the newborn. J Pediatr Gastroenterol Nutr 1994; 18:25.
  22. Schanler RJ, Shulman RJ, Prestridge LL. Parenteral nutrient needs of very low birth weight infants. J Pediatr 1994; 125:961.
  23. Klein CJ. Nutrient requirements for preterm infant formulas. J Nutr 2002; 132:1395S.
  24. Pierro A, Carnielli V, Filler RM, et al. Characteristics of protein sparing effect of total parenteral nutrition in the surgical infant. J Pediatr Surg 1988; 23:538.
  25. Porcelli Jr PJ, Sisk PM. Increased parenteral amino acid administration to extremely low-birth-weight infants during early postnatal life. J Pediatr Gastroenterol Nutr 2002; 34:174.
  26. Burattini I, Bellagamba MP, Spagnoli C, et al. Targeting 2.5 versus 4 g/kg/day of amino acids for extremely low birth weight infants: a randomized clinical trial. J Pediatr 2013; 163:1278.
  27. Clark RH, Chace DH, Spitzer AR, Pediatrix Amino Acid Study Group. Effects of two different doses of amino acid supplementation on growth and blood amino acid levels in premature neonates admitted to the neonatal intensive care unit: a randomized, controlled trial. Pediatrics 2007; 120:1286.
  28. Tan MJ, Cooke RW. Improving head growth in very preterm infants--a randomised controlled trial I: neonatal outcomes. Arch Dis Child Fetal Neonatal Ed 2008; 93:F337.
  29. Yang J, Chang SS, Poon WB. Relationship Between Amino Acid and Energy Intake and Long-Term Growth and Neurodevelopmental Outcomes in Very Low Birth Weight Infants. JPEN J Parenter Enteral Nutr 2016; 40:820.
  30. Helms RA, Christensen ML, Mauer EC, Storm MC. Comparison of a pediatric versus standard amino acid formulation in preterm neonates requiring parenteral nutrition. J Pediatr 1987; 110:466.
  31. Heird WC, Dell RB, Helms RA, et al. Amino acid mixture designed to maintain normal plasma amino acid patterns in infants and children requiring parenteral nutrition. Pediatrics 1987; 80:401.
  32. Heird WC, Hay W, Helms RA, et al. Pediatric parenteral amino acid mixture in low birth weight infants. Pediatrics 1988; 81:41.
  33. Roberts SA, Ball RO, Filler RM, et al. Phenylalanine and tyrosine metabolism in neonates receiving parenteral nutrition differing in pattern of amino acids. Pediatr Res 1998; 44:907.
  34. Van Goudoever JB, Sulkers EJ, Timmerman M, et al. Amino acid solutions for premature neonates during the first week of life: the role of N-acetyl-L-cysteine and N-acetyl-L-tyrosine. JPEN J Parenter Enteral Nutr 1994; 18:404.
  35. Zelikovic I, Chesney RW, Friedman AL, Ahlfors CE. Taurine depletion in very low birth weight infants receiving prolonged total parenteral nutrition: role of renal immaturity. J Pediatr 1990; 116:301.
  36. Viña J, Vento M, García-Sala F, et al. L-cysteine and glutathione metabolism are impaired in premature infants due to cystathionase deficiency. Am J Clin Nutr 1995; 61:1067.
  37. Denno R, Rounds JD, Faris R, et al. Glutamine-enriched total parenteral nutrition enhances plasma glutathione in the resting state. J Surg Res 1996; 61:35.
  38. Rivera A Jr, Bell EF, Bier DM. Effect of intravenous amino acids on protein metabolism of preterm infants during the first three days of life. Pediatr Res 1993; 33:106.
  39. Dunham B, Marcuard S, Khazanie PG, et al. The solubility of calcium and phosphorus in neonatal total parenteral nutrition solutions. JPEN J Parenter Enteral Nutr 1991; 15:608.
  40. Laine L, Shulman RJ, Pitre D, et al. Cysteine usage increases the need for acetate in neonates who receive total parenteral nutrition. Am J Clin Nutr 1991; 54:565.
  41. Poindexter BB, Ehrenkranz RA, Stoll BJ, et al. Parenteral glutamine supplementation does not reduce the risk of mortality or late-onset sepsis in extremely low birth weight infants. Pediatrics 2004; 113:1209.
  42. de Kieviet JF, Oosterlaan J, Vermeulen RJ, et al. Effects of glutamine on brain development in very preterm children at school age. Pediatrics 2012; 130:e1121.
  43. Moe-Byrne T, Brown JV, McGuire W. Glutamine supplementation to prevent morbidity and mortality in preterm infants. Cochrane Database Syst Rev 2016; 4:CD001457.
  44. Van Goudoever JB, Colen T, Wattimena JL, et al. Immediate commencement of amino acid supplementation in preterm infants: effect on serum amino acid concentrations and protein kinetics on the first day of life. J Pediatr 1995; 127:458.
  45. van Lingen RA, van Goudoever JB, Luijendijk IH, et al. Effects of early amino acid administration during total parenteral nutrition on protein metabolism in pre-term infants. Clin Sci (Lond) 1992; 82:199.
  46. Anderson TL, Muttart CR, Bieber MA, et al. A controlled trial of glucose versus glucose and amino acids in premature infants. J Pediatr 1979; 94:947.
  47. Rivera A Jr, Bell EF, Stegink LD, Ziegler EE. Plasma amino acid profiles during the first three days of life in infants with respiratory distress syndrome: effect of parenteral amino acid supplementation. J Pediatr 1989; 115:465.
  48. Blanco CL, Gong AK, Green BK, et al. Early changes in plasma amino acid concentrations during aggressive nutritional therapy in extremely low birth weight infants. J Pediatr 2011; 158:543.
  49. van den Akker CH, te Braake FW, Wattimena DJ, et al. Effects of early amino acid administration on leucine and glucose kinetics in premature infants. Pediatr Res 2006; 59:732.
  50. Trivedi A, Sinn JK. Early versus late administration of amino acids in preterm infants receiving parenteral nutrition. Cochrane Database Syst Rev 2013; :CD008771.
  51. te Braake FW, van den Akker CH, Wattimena DJ, et al. Amino acid administration to premature infants directly after birth. J Pediatr 2005; 147:457.
  52. Poindexter BB, Langer JC, Dusick AM, et al. Early provision of parenteral amino acids in extremely low birth weight infants: relation to growth and neurodevelopmental outcome. J Pediatr 2006; 148:300.
  53. Valentine CJ, Fernandez S, Rogers LK, et al. Early amino-acid administration improves preterm infant weight. J Perinatol 2009; 29:428.
  54. Vlaardingerbroek H, Vermeulen MJ, Rook D, et al. Safety and efficacy of early parenteral lipid and high-dose amino acid administration to very low birth weight infants. J Pediatr 2013; 163:638.
  55. Friedman Z, Danon A, Stahlman MT, Oates JA. Rapid onset of essential fatty acid deficiency in the newborn. Pediatrics 1976; 58:640.
  56. Gutcher GR, Farrell PM. Intravenous infusion of lipid for the prevention of essential fatty acid deficiency in premature infants. Am J Clin Nutr 1991; 54:1024.
  57. Gilbertson N, Kovar IZ, Cox DJ, et al. Introduction of intravenous lipid administration on the first day of life in the very low birth weight neonate. J Pediatr 1991; 119:615.
  58. Simmer K, Rao SC. Early introduction of lipids to parenterally-fed preterm infants. Cochrane Database Syst Rev 2005; :CD005256.
  59. Haumont D, Deckelbaum RJ, Richelle M, et al. Plasma lipid and plasma lipoprotein concentrations in low birth weight infants given parenteral nutrition with twenty or ten percent lipid emulsion. J Pediatr 1989; 115:787.
  60. Haumont D, Richelle M, Deckelbaum RJ, et al. Effect of liposomal content of lipid emulsions on plasma lipid concentrations in low birth weight infants receiving parenteral nutrition. J Pediatr 1992; 121:759.
  61. Kao LC, Cheng MH, Warburton D. Triglycerides, free fatty acids, free fatty acids/albumin molar ratio, and cholesterol levels in serum of neonates receiving long-term lipid infusions: controlled trial of continuous and intermittent regimens. J Pediatr 1984; 104:429.
  62. Greene HL, Hazlett D, Demaree R. Relationship between Intralipid-induced hyperlipemia and pulmonary function. Am J Clin Nutr 1976; 29:127.
  63. Periera GR, Fox WW, Stanley CA, et al. Decreased oxygenation and hyperlipemia during intravenous fat infusions in premature infants. Pediatrics 1980; 66:26.
  64. Brans YW, Dutton EB, Andrew DS, et al. Fat emulsion tolerance in very low birth weight neonates: effect on diffusion of oxygen in the lungs and on blood pH. Pediatrics 1986; 78:79.
  65. Spear ML, Stahl GE, Hamosh M, et al. Effect of heparin dose and infusion rate on lipid clearance and bilirubin binding in premature infants receiving intravenous fat emulsions. J Pediatr 1988; 112:94.
  66. Drenckpohl D, McConnell C, Gaffney S, et al. Randomized trial of very low birth weight infants receiving higher rates of infusion of intravenous fat emulsions during the first week of life. Pediatrics 2008; 122:743.
  67. Gura KM, Duggan CP, Collier SB, et al. Reversal of parenteral nutrition-associated liver disease in two infants with short bowel syndrome using parenteral fish oil: implications for future management. Pediatrics 2006; 118:e197.
  68. Sosenko IR, Rodriguez-Pierce M, Bancalari E. Effect of early initiation of intravenous lipid administration on the incidence and severity of chronic lung disease in premature infants. J Pediatr 1993; 123:975.
  69. Park W, Paust H, Schröder H. Lipid infusion in premature infants suffering from sepsis. JPEN J Parenter Enteral Nutr 1984; 8:290.
  70. Rubin M, Naor N, Sirota L, et al. Are bilirubin and plasma lipid profiles of premature infants dependent on the lipid emulsion infused? J Pediatr Gastroenterol Nutr 1995; 21:25.
  71. Spear ML, Stahl GE, Paul MH, et al. The effect of 15-hour fat infusions of varying dosage on bilirubin binding to albumin. JPEN J Parenter Enteral Nutr 1985; 9:144.
  72. Hammerman C, Aramburo MJ. Decreased lipid intake reduces morbidity in sick premature neonates. J Pediatr 1988; 113:1083.
  73. Pitkänen O, Hallman M, Andersson S. Generation of free radicals in lipid emulsion used in parenteral nutrition. Pediatr Res 1991; 29:56.
  74. Helbock HJ, Motchnik PA, Ames BN. Toxic hydroperoxides in intravenous lipid emulsions used in preterm infants. Pediatrics 1993; 91:83.
  75. Kapoor V, Glover R, Malviya MN. Alternative lipid emulsions versus pure soy oil based lipid emulsions for parenterally fed preterm infants. Cochrane Database Syst Rev 2015; :CD009172.
  76. MacMahon P, Blair ME, Treweeke P, Kovar IZ. Association of mineral composition of neonatal intravenous feeding solutions and metabolic bone disease of prematurity. Arch Dis Child 1989; 64:489.
  77. Koo WW. Parenteral nutrition-related bone disease. JPEN J Parenter Enteral Nutr 1992; 16:386.
  78. Glasgow JF, Thomas PS. Rachitic respiratory distress in small preterm infants. Arch Dis Child 1977; 52:268.
  79. Fitzgerald KA, MacKay MW. Calcium and phosphate solubility in neonatal parenteral nutrient solutions containing TrophAmine. Am J Hosp Pharm 1986; 43:88.
  80. Pelegano JF, Rowe JC, Carey DE, et al. Simultaneous infusion of calcium and phosphorus in parenteral nutrition for premature infants: use of physiologic calcium/phosphorus ratio. J Pediatr 1989; 114:115.
  81. Hoehn GJ, Carey DE, Rowe JC, et al. Alternate day infusion of calcium and phosphate in very low birth weight infants: wasting of the infused mineral. J Pediatr Gastroenterol Nutr 1987; 6:752.
  82. Prestridge LL, Schanler RJ, Shulman RJ, et al. Effect of parenteral calcium and phosphorus therapy on mineral retention and bone mineral content in very low birth weight infants. J Pediatr 1993; 122:761.
  83. Koo WK, Tsang RC. Calcium, magnesium, phosphorus, and vitamin D. In: Nutritional Needs of the Preterm Infant, Tsang RC, Lucas A, Uauy R, Zlotkin S (Eds), Williams & Wilkins, Baltimore 1993. p.135.
  84. Darlow BA, Graham PJ, Rojas-Reyes MX. Vitamin A supplementation to prevent mortality and short- and long-term morbidity in very low birth weight infants. Cochrane Database Syst Rev 2016; :CD000501.
  85. Shenai JP. Vitamin A. In: Nutritional Needs of the Preterm Infant, Tsang RC, Lucas A, Uauy R, Zlotkin S (Eds), Williams & Wilkins, Baltimore 1993. p.87.
  86. Zachman RD. Retinol (vitamin A) and the neonate: special problems of the human premature infant. Am J Clin Nutr 1989; 50:413.
  87. Bates CJ, Liu DS, Fuller NJ, Lucas A. Susceptibility of riboflavin and vitamin A in breast milk to photodegradation and its implications for the use of banked breast milk in infant feeding. Acta Paediatr Scand 1985; 74:40.
  88. Baeckert PA, Greene HL, Fritz I, et al. Vitamin concentrations in very low birth weight infants given vitamins intravenously in a lipid emulsion: measurement of vitamins A, D, and E and riboflavin. J Pediatr 1988; 113:1057.
  89. Porcelli PJ, Greene HL, Adcock EW. Retinol (vitamin A) and riboflavin (vitamin B2) administration and metabolism in very low birth weight infants. Semin Perinatol 1992; 16:170.
  90. Raju TN, Langenberg P, Bhutani V, Quinn GE. Vitamin E prophylaxis to reduce retinopathy of prematurity: a reappraisal of published trials. J Pediatr 1997; 131:844.
  91. Phelps DL, Rosenbaum AL, Isenberg SJ, et al. Tocopherol efficacy and safety for preventing retinopathy of prematurity: a randomized, controlled, double-masked trial. Pediatrics 1987; 79:489.
  92. Puklin JE, Simon RM, Ehrenkranz RA. Influence on retrolental fibroplasia of intramuscular vitamin E administration during respiratory distress syndrome. Ophthalmology 1982; 89:96.
  93. Watts JL, Milner RA, McCormick AO. Failure of vitamin E to prevent RLF. Clin Invest Med 1985; 8:A176.
  94. Ehrenkranz RA, Ablow RC, Warshaw JB. Effect of vitamin E on the development of oxygen-induced lung injury in neonates. Ann N Y Acad Sci 1982; 393:452.
  95. Saldanha RL, Cepeda EE, Poland RL. The effect of vitamin E prophylaxis on the incidence and severity of bronchopulmonary dysplasia. J Pediatr 1982; 101:89.
  96. Watts JL, Milner R, Zipursky A, et al. Failure of supplementation with vitamin E to prevent bronchopulmonary dysplasia in infants less than 1,500 g birth weight. Eur Respir J 1991; 4:188.
  97. Ehrenkranz RA. Vitamin E and retinopathy of prematurity: still controversial. J Pediatr 1989; 114:801.
  98. Chiswick ML, Johnson M, Woodhall C, et al. Protective effect of vitamin E (DL-alpha-tocopherol) against intraventricular haemorrhage in premature babies. Br Med J (Clin Res Ed) 1983; 287:81.
  99. Law MR, Wijewardene K, Wald NJ. Is routine vitamin E administration justified in very low-birthweight infants? Dev Med Child Neurol 1990; 32:442.
  100. Sinha S, Davies J, Toner N, et al. Vitamin E supplementation reduces frequency of periventricular haemorrhage in very preterm babies. Lancet 1987; 1:466.
  101. Levy R, Herzberg GR, Andrews WL, et al. Thiamine, riboflavin, folate, and vitamin B12 status of low birth weight infants receiving parenteral and enteral nutrition. JPEN J Parenter Enteral Nutr 1992; 16:241.
  102. Moore MC, Greene HL, Phillips B, et al. Evaluation of a pediatric multiple vitamin preparation for total parenteral nutrition in infants and children. I. Blood levels of water-soluble vitamins. Pediatrics 1986; 77:530.
  103. Greene HL, Smith R, Pollack P, et al. Intravenous vitamins for very-low-birth-weight infants. J Am Coll Nutr 1991; 10:281.
  104. Bhatia J. Palliative care in the fetus and newborn. J Perinatol 2006; 26 Suppl 1:S24.
  105. Greene HL, Hambidge KM, Schanler R, Tsang RC. Guidelines for the use of vitamins, trace elements, calcium, magnesium, and phosphorus in infants and children receiving total parenteral nutrition: report of the Subcommittee on Pediatric Parenteral Nutrient Requirements from the Committee on Clinical Practice Issues of the American Society for Clinical Nutrition. Am J Clin Nutr 1988; 48:1324.
  106. Zlotkin SH, Buchanan BE. Meeting zinc and copper intake requirements in the parenterally fed preterm and full-term infant. J Pediatr 1983; 103:441.
  107. Vanek VW, Borum P, Buchman A, et al. A Call to Action to Bring Safer Parenteral Micronutrient Products to the U.S. Market. Nutr Clin Pract 2015; 30:559.
  108. Darlow BA, Austin NC. Selenium supplementation to prevent short-term morbidity in preterm neonates. Cochrane Database Syst Rev 2003; :CD003312.
  109. Schmidt-Sommerfeld E, Penn D, Wolf H. Carnitine deficiency in premature infants receiving total parenteral nutrition: effect of L-carnitine supplementation. J Pediatr 1983; 102:931.
  110. Bonner CM, DeBrie KL, Hug G, et al. Effects of parenteral L-carnitine supplementation on fat metabolism and nutrition in premature neonates. J Pediatr 1995; 126:287.
  111. Pande S, Brion LP, Campbell DE, et al. Lack of effect of L-carnitine supplementation on weight gain in very preterm infants. J Perinatol 2005; 25:470.
  112. Kumar M, Kabra NS, Paes B. Role of carnitine supplementation in apnea of prematurity: a systematic review. J Perinatol 2004; 24:158.
  113. Nutrition & Gastroenterology Clinical Review Committee. Nutrition support. In: Guidelines for the Acute Care of the Neonate, Adams JM, Garcia-Prats JA, Schanler RJ, et al (Eds), Newborn Section, Department of Pediatrics, Baylor College of Medicine, Houston 2002. p.43.
  114. Martin CR, Brown YF, Ehrenkranz RA, et al. Nutritional practices and growth velocity in the first month of life in extremely premature infants. Pediatrics 2009; 124:649.
  115. Blanco CL, Falck A, Green BK, et al. Metabolic responses to early and high protein supplementation in a randomized trial evaluating the prevention of hyperkalemia in extremely low birth weight infants. J Pediatr 2008; 153:535.
  116. Cronin WA, Germanson TP, Donowitz LG. Intravascular catheter colonization and related bloodstream infection in critically ill neonates. Infect Control Hosp Epidemiol 1990; 11:301.