Journal of Pediatrics. 1982 Jun;69(6):768-72. William F. Meyers, MD, and John J. Herbst, MD
“In patients with GER, less reflux occurred while upright than supine during awake but not during asleep periods. The 30-degree elevated prone position was superior to the supine or upright positions while patients were awake or asleep.”
Article: Effect of bed head elevation during sleep in symptomatic patients of nocturnal gastroesophageal reflux.
“Bed head elevation reduced esophageal acid exposure and acid clearance time in nocturnal (supine) refluxers and led to some relief from heartburn and sleep disturbance.”
Unfortunately, the current AAP recommendations regarding the ineffectiveness of the inclined supine sleeping in reducing reflux, are based on studies done with esophageal pH monitoring test. This test, developed in the 70’s, gained popularity in the mid 90’s and were used then to evaluate reflux, however, the test was subsequently discovered to be significantly flawed in evaluating reflux in infants.
The pH tests are inaccurate because they do not measure or account for nonacidic post feed reflux—the most common type of reflux in infancy. Babies reflux more after feeding, and usually, such reflux are buffered by milk and would not be reflected with pH monitoring.
In fact, the uptodate website specifically states that “these studies rarely are useful in evaluating gastroesophageal reflux (GER) or establishing the diagnosis of gastroesophageal reflux disease (GERD) in infants.”