Recommended Sleep Position: Supine for Infants, Left Lateral for Adults
For infants under 1 year of age, the supine position (wholly on the back) is the only recommended sleep position to reduce the risk of Sudden Infant Death Syndrome (SIDS). 1, 2 For adults, particularly those with gastroesophageal reflux disease (GERD), the left lateral decubitus position is recommended. 3, 4
Infant Sleep Positioning
Supine Position (Back Sleeping) for Infants
- The American Academy of Pediatrics strongly recommends placing infants wholly on their back for every sleep period until 1 year of age 2
- Side sleeping is not safe and should never be used for infants 1
- The prone (stomach) position significantly increases SIDS risk with odds ratios ranging from 2.3 to 13.1 1
Why Supine Position is Safest for Infants
- Reduces risk of rebreathing expired gases (preventing hypercapnia and hypoxia)
- Decreases risk of overheating
- Maintains proper autonomic control of the cardiovascular system
- Ensures better cerebral oxygenation 1, 2
Common Misconceptions About Infant Sleep Position
- Choking risk: The supine position does not increase risk of choking or aspiration, even in infants with gastroesophageal reflux 1
- Sleep quality: While infants may wake more frequently in the supine position, this is actually protective as the ability to arouse from sleep is an important physiologic response to stressors 1
Special Considerations for Infants
- Once an infant can roll from supine to prone and from prone to supine (typically 4-6 months), they may remain in the position they assume 1
- Supervised "tummy time" when awake is important for motor development but should never be used for sleep 2
Adult Sleep Positioning
Left Lateral Position for Adults
- For adults, particularly those with GERD, the left lateral decubitus position is recommended 3, 4
- Recent research shows that sleeping on the left side is associated with:
- Significantly shorter esophageal acid exposure time
- Faster esophageal acid clearance
- Improved GERD symptoms 4
Evidence Supporting Left Lateral Position
- A 2023 systematic review and meta-analysis found that the left lateral decubitus position decreases acid exposure time and acid clearance time compared to right lateral and supine positions 3
- A 2022 study using concurrent monitoring of sleep position and esophageal pH showed significantly shorter acid exposure time in the left lateral position (median 0.0%) compared to right lateral (median 1.2%) and supine positions (median 0.6%) 4
- The esophageal acid clearance time was also significantly shorter in the left lateral position (median 35 seconds) compared to supine (median 76 seconds) and right lateral positions (median 90 seconds) 4
Practical Implementation
- For adults with GERD, using a body pillow or positioning device that maintains the left lateral position while elevating the head/torso may provide additional benefit 5
- Electronic sleep positional therapy that increases duration of left lateral sleep and decreases right lateral sleep has shown improvement in nocturnal GERD symptoms 3
Key Takeaways
- For infants: Always place on back (supine) for every sleep until 1 year of age
- For adults: Left lateral position is optimal, especially for those with GERD
- Consistency in positioning is important for developing safe sleep habits