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A Systematic Review of Positioning of Preterm Infants for Optimal Physiological Development.

JBI Database of Systematic Reviews and Implementation Reports: Volume 3 - Issue 7 - p 1–11
doi: 10.11124/jbisrir-2005-706
Systematic Review Protocol

Primary reviewer: Wilawan Picheansathian Telephone: (66)-53–949007 Facsimile: (66)-53–217145 Email:

Secondary reviewer: Patcharee Woragidpoolpol Telephone: (66)-53–949007 Facsimile: (66)-53–217145 Email:


Premature infants are at risk for developmental delays. Due to immaturity, they often lack adequate muscle tone and are at risk for developing abnormal movement patterns as well as skeleton deformation.1 Some delays are related to improper body mechanics rather than neurological impairment. Hypotonia or decreased muscle tone normally observed in the infant born 28 to 30 weeks’ gestational. Proper position of premature infants may promote normal motor development while minimizing development of abnormal movement patterns.

Positioning of preterm infants is a basic neonatal nursing care. It includes supine, prone, side-lying, and head up tilted position. Several studies demonstrated a variety outcome affected by different body positioning of preterm infants. In addition, several studies indicated a strong association between prone sleep position and Sudden Infant Death Syndrome (SIDS).2 Therefore, The Task Force of the American Academy of Pediatrics (AAP)3 recommends the non-prone sleeping position for asymptomatic preterm infants to prevent SIDS. As a result of these findings, there is increasing pressure to avoid the prone sleep position in all infants, including preterm infants who do not have respiratory distress and are being readied for hospital discharge. This presents a dilemma for nurses and paediatricians caring for healthy preterm infants because other studies indicate that preterm infants in the prone position spend less time awake and more quiet sleep,4–5 less cry and less move.6–7 What constitutes the most advantageous sleep position for preterm infants remains undetermined.

Furthermore, previous studies found that preterm infants with lie in a prone position compared to those in a supine position have early motor milestone,8 decreased energy expenditure, more rapid gastric emptying and less gastric reflux,9–10 greater chest wall synchrony and improved respiration,11–12 decrease respiratory rate,6,11 greater tidal volume, minute volume, elastic work, inspiratory and tidal viscous work, total work of breathing, and work of ventilating,13 improved oxygenation in both spontaneous breathing preterm infants12,14–16 and intubated preterm infants.6,17–19 Despite the physiologic benefits of the prone position, the very low birth weight infant is at risk for postural abnormalities such as flattened posture that is known to affect developmental milestones up to age six.20 Three studies indicated that the supine positioning in healthy preterm infants was associated with higher respiratory rate than prone position,11,20–21 but the other study demonstrated that there were no significant differences in the incidence of clinically significant apnea, bradycardia, or desaturation between supine and prone positions.22 In addition, some studies found that head elevated tilt position reduces hypoxemic and bradycardia events in preterm infants,23–24 and increases transcutaneous PO2.25 However, a comprehensive literature review during 1966–2000 by Monterosso et al26 found that the prone position is preferred for very low birth weight infants because it promotes development of pulmonary, cardiovascular, sleep state organizational, and gastrointestinal functions and facilitates the preterm infants recovering from the respiratory complications associated with immaturity. In addition, the results of a systematic review suggested that prone position slightly improved the oxygenation in neonates undergoing mechanical ventilation.17 However, there was no evidence concerning whether particular body positions during mechanical ventilation of the neonate were effective in producing clinical relevant improvements.

Although research shows advantages and disadvantages for both supine and prone position among preterm infants to their physiological outcomes, there is a trend remains toward keeping preterm infants in a supine position; mainly for ease of observation and handling. This review evaluates the clinical evidence that investigates the effects of positioning of preterm infants including prone position, supine position, side-lying position, and head elevated tilt position on physiological outcomes including respiratory function, hemodynamic, neuromotor development, gastric function and sleep states.


Objective of this review is to determine the best available evidence related to the positioning of preterm infants. The following questions will be addressed in this review:

  1. What are the physiological outcomes affected by different positioning of preterm infants?
  2. What is the best position for promoting sleep among preterm infants?

Criteria for considering studies for this review:

Types of participants

This review considered all studies that included healthy infants born before 37 weeks of gestational age in any hospital setting, including those admitted to newborn nurseries, neonatal intensive care units, and medical clinics.

Types of Intervention

Interventions of interest are those related to positioning of preterm infants including prone, supine, side-lying, and head elevated tilt position.

Types of outcome measures

Outcomes of interest are as follow:

  • physiologic effects including respiratory function ( oxygen saturation, tidal volume, functional residual capacity, respiratory rate ), hemodynamic ( heart rate, blood pressure ), neuromotor development ( motor activity ), and gastric function ( gastro esophageal reflux, gastric residual )
  • sleep state classified as awake, active sleep, quiet sleep or indeterminate sleep.

Types of studies

This review will consider randomized clinical trails (RCTs) that explore different positions in preterm infant. In the absence of RCTs, Quasiexperimental design will be reviewed for possible conclusion in a narrative summary to enable the identification of current best evidence regarding position in preterm infants.

Exclusion criteria:

This review will excluded articles that are expert opinion, literature reviews, or included no detailed results of the study. In addition, studies included infants who had medical problems or were on medication at the time of study will be excluded from this review.

Search strategy:

Both published and unpublished studies will be used. Three stages of search strategy include:

  1. Limited search from journal indexes from MEDLINE, DARE and CINAHL. An analysis of the text words contained in the title, abstracts, and subject descriptors / MeSH terms of relevant articles will be considered to identify additional key words. In addition to this, a number of electronic databases will be searched to locate relevant studies in this subject area. Databases to be searched include:
    • CINAHL
    • EMBASE
    • Cochrane Library
    • MEDLINE/PubMed
    • DARE
    • ProQuest 5000
    • Science Direct
    • Currents @ OVID
    • Centre for Reviews and Dissemination databases
    • Other applicable databases
  2. Individual search strategies will be developed for each database, adopting the different terminology of index thesauri if available.
  3. In order to avoid publication bias, hand searching of the most recent issues of following journals will be searched for additional references: Journal of Pediatric Nursing, Pediatrics, Archives of Disease in Childhood, Pediatric Physical Therapy, and Neonatal Network. The search will also be conducted to locate relevant unpublished materials, such as conference papers, research reports, and dissertations. The sources searched to locate unpublished studies will include:
    • Dissertation Abstracts
    • Index to Theses
    • Conference proceedings
    • WWW sites of relevant associations
    • Direct communication with neonatal organizations, and neonatal nurse researchers.
  4. Searches will include English and foreign language publications. Assessment for inclusion of foreign language publication will be based on the English language abstracted, when available.
  5. Content experts will also be contacted in order to provide other alternatives for securing relevant literature.
  6. All included literature will have their reference lists searched for additional relevant source journals.

Keywords include:

All studies retrieved of a combination keywords will be reviewed regarding their title, abstract, and descriptive terms for meeting the inclusion criteria. Keywords include: position, positioning, sleep, prone, supine, side-lying, head elevated tilt, premie, preterm, premature and infants.

Methods of the review:

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Critical appraisal

All studies that meet the inclusion criteria will be assessed for methodological quality using an evaluation tool which will be developed on an existing tool used by the Joanna Briggs institution (JBI) for Evidence Based Nursing (Appendices 2 and 3). Two reviewers will independently assess all articles, and disagreements between reviewers will be resolved by discussion with a third reviewer. Data that can be used as evidence will be extracted, and the level of evidence will be evaluated.

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Data extraction

Two reviewers will extract data independently, using a tool designed for this purpose (Appendix 4). A third reviewer will be asked to resolve any differences if the initial reviewers cannot reach agreement. When necessary, the principal primary researcher will be contacted to obtain missing information.

Data analysis:

If two or more comparable studies are identified, data will be pooled in statistical meta-analysis using Review Manager software. Studies will be considered comparable if they have drawn subjects from comparable populations, using similar interventions and had comparable outcomes measures. Double data entry will be used to minimize the risk of data entry errors.

Heterogeneity between combined studies will be tested using standard chisquare test and visual inspective of the graphic presentation of the results. Where possible, odds ratio (for categorical outcome data) or weighted mean differences (for continuous) and their 95% confidence intervals will be calculated for each study. If statistical pooling of results is not appropriate, the findings will be summarized in a narrative form.

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1. Young J. Positioning premature babies, nursing preterm babies in intensive care: which position is best? J Neonatal Nurs 1994;September:27-30.
2. Willinger M, Hoffman HJ, Wu KT, Hou JR, Kessler RC, Ward SL, et al. Factors associated with the transition to nonprone sleep positions of infants in the United States. JAMA 1998;280 (4):329-35.
3. American Academy of Pediatrics Task Force on Infant Positioning and SIDS. Positioning and Sudden Infant Death Syndrome (SIDS). Pediatrics 1996; 98: 1216-8.
3. Masterson J, Zucker C, Schulze K. Prone and supine positioning effects on energy expenditure and behavior of low birth weight neonates. Pediatrics 1987;80:689-92.
4. Goto K, Maeda T, Mimiran M, Ariagno R. Effects of prone and supine position on sleep characteristics in preterm infants. Psychiatry Clin Neurosci 1999;53:315-7.
6. Fox MD, Molesky MG. The effects of prone and supine positioning on arterial oxygen pressure. Neonatal Network 1990;8(4):25-9.
7. Myers MM, Fifer WP, Schaeffer L, Sahni R, Ohira-Kist K, Stark RI, Schulze KF. Effects of sleeping position and time after feeding on the organization of sleep/awake states in prematurely born infants. Sleep 1998;21(4):343-9.
8. Davis BE, Moon RY, Sachs HC, Ottolini MC. Effects of sleep position on infant motor development. Pediatrics 1998,102(5): 1135-9.
9. Ewer AK, James ME, Tobin JM. Prone and left lateral positioning reduce gastro-oesophageal reflux in preterm infants. Arch Dis Child Fetal Neonatal Ed 1999;81:F201-5.
10. Blumenthal I, Lealman GT. Effect of posture on gastro-esophageal reflux in the newborn. Arch Dis Childhood 1982;57:555-6.
11. Martin RJ, DiFiore JM, Korenke CB, Randal H, Miller MJ, Brooks LJ. Vulnerability of respiratory control in healthy preterm infants placed supine. J Pediatr 1995;127:609-14.
12. Martin RJ, Herrell N, Rubin D, Fanaroff A. Effect of supine and prone positions on arterial oxygen tension in the preterm infant. Pediatrics 1979; 63(4): 528-31.
13. Hutchison AA, Ross KR, Russell G. The effect of posture on ventilation and lung mechanics in preterm and light-for-date infants. Pediatr 1979;64(4):429-32.
14. Dimitriou G, Greenough A, Pink L, McGhee A, Hickey A, & Rafferty GF. Effect of posture on oxygenation and respiratory muscle strength in convalescent infants. Arch Dis Child Fetal Neonatal Ed 2002;86:F147-50.
15. Lioy J, Manginello FP. A comparison of prone and supine positioning in the immediate postextubation period of neonates. J Pediatr 1988;112(6):982-4.
16. Jaroenswat P. The effects of positioning on oxygenation and sleep state in preterm infants. Chiang Mai Bullentin 2001; 40(2): 53-60.
17. Balaguer A, Escribano J, Roqué M. Infant positions in neonates receiving mechanical ventilation. The Cochrane Database of systematic Reviews 2003, Issue 2. Available from:URL:http://www.cochrane/org.
18. Bjornson KF, Deitz JC, Blackburn S, Billingsley F, Garcia J, Hays R. The effect of body position on the oxygen saturation of ventilated preterm infants. Pediatr Physical Therapy 1992, 4(3): 109-14.
19. Wagaman MJ, Shutack JG, Moomjian AS, Schwartz JG, Shaffer TH, Fox WW. Improved oxygenation and lung compliance with prone positioning of neonates. J Pediatr 1979;94(5): 787-91.
20. Monterosso L, Coenen A, Percival P, Evans S. Effect of a postural support nappy on “flattened posture” of the lower extremities in very preterm infants. J Paediatr Child Health 1995;31:350-4.
21. Maynard V, Bignall S, Kitchen S. Effect of positioning on respiratory synchrony in non-ventilated pre-term infants. Physiother Res Int 2000;5(2):96-110.
22. Keene DJ, Wimmer Jr JE, Mathew OP. Does supine positioning increase apnea, bradycardia, and desaturation in preterm infants? J Perinatol 2000;1:17-20.
23. Jenni OG, von Siebenthal K, Wolf M, Keel M, Duc G, Bucher HU. Effect of nursing in the head elevated tilt position (15 degrees) on the incidence of bradycardia and hypoxemic episodes in preterm infants. Pediatrics 1997;100(4): 622-5.
24. Oskar J, Kurt S, Martin W, Matthias K, Gabriel D, Hans B. Effect of nursing in the head elevated tilt position (15 degree sign) on the incidence of bradycardia and hypoxemic episodes in preterm infants. Pediatrics 1997;100(4):622-5.
25. Thoresen M, Cowan F, Whitelaw A. Effect of tilting on oxygenation in newborn infants. Arch Dis Childhood 1988;63(3):315-17.
26. Monterosso L, Kristjanson L, Cole J. Neuromotor development and physiologic effects of positioning in very low birth weight infants. J Obstetr Gyneco Neonat Nurs 2002;31(2):138-46.
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Appendix 1 Inclusion criteria



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Appendix 2 Critical Appraisal Form for Quasi-Experimental Design



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Appendix 3 Critical Appraisal Form for RCTs



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Appendix 4 Data Extraction Form



© 2005 by Lippincott Williams & Wilkins, Inc.