Abstract: We extracted data from 53 studies. We included 24 studies with a total of 581 participants. Three studies used a parallel-group, randomised design which compared prone and supine positions only. The remaining 21 studies used a randomised cross-over design. These studies compared prone, supine, lateral, elevated and flat positions. Prone positioning was significantly more beneficial than supine positioning in terms of oxygen saturation (mean difference (MD) 1.97%, 95% CI 1.18 to 2.77), arterial oxygen (MD 6.24 mm Hg, 95% confidence interval (CI) 2.20 to 10.28), episodes of hypoxaemia (MD -3.46, 95% CI -4.60 to -2.33) and thoracoabdominal synchrony (MD -30.76, 95% CI -41.39 to -20.14). No adverse effects were identified. There were no statistically significant differences between any other positions. As the majority of studies did not describe how possible biases were addressed, the potential for bias in these findings is unclear. The prone position was significantly superior to the supine position in terms of oxygenation. However, as most participants were ventilated preterm infants, the benefits of prone positioning may be most relevant to these infants. In addition, although placing infants and children in the prone position may improve respiratory function, the association of SIDS with prone positioning means that infants should only be placed in this position while under continuous cardiorespiratory monitoring.

Plain-language summary: We included 24 studies with a total of 581 participants. Lying on the front (the prone position) was better than lying on the back (the supine position) for oxygenating the blood but the difference was small. The increase in oxygen saturation on average increased by 2%. This finding was based on data from nine studies (195 children, 165 preterm and 95 ventilated) measuring this outcome. The rapid rate of breathing with respiratory distress was slightly lower in the prone position (on average four breaths/minute lower) based on six studies (100 infants aged up to one month, 59 ventilated). No adverse effects were identified. There were no obvious differences with other positions. As most of the 581 children in these studies were preterm babies (60%) and (70%) ventilated by machine, the benefits of prone positioning may be most relevant to these infants. ***It is important to remember that these children were hospitalised. Therefore, given the association of the prone position with sudden infant death syndrome (SIDS), the prone position should not be used for children unless they are in hospital and their breathing is constantly monitored. As the majority of studies did not describe how possible biases in the design of the study were addressed, the potential for bias in these findings is unclear. Also the findings of this review are limited by the small number of participants in studies, changes in infants and children were only measured for short time periods and the small changes in oxygenation which were seen in this review are not as meaningful as other measures of illness and recovery. Only five studies looked at children older than one year and few studies compared positions other than prone and supine.