Mechanisms of gastroesophageal reflux in healthy premature infants

J Pediatr. 1998 Nov;133(5):650-4. doi: 10.1016/s0022-3476(98)70106-4.


Objectives: The aim of this study was to characterize the motor events responsible for gastroesophageal reflux (GER) and esophageal acid clearance in a cohort of healthy preterm infants.

Study design: Esophageal motility was recorded for 2 to 3 hours after a feeding in 24 preterm infants, 31 to 38 weeks' postmenstrual age, by using a sleeveside hole micromanometric assembly incorporating a pH probe.

Results: Sixty acid GER episodes were recorded by pH probe, and 133 non-acid GER episodes were recorded manometrically by the presence of esophageal common cavities. Of the 193 GER episodes, 159 (82%) were associated with transient lower esophageal sphincter relaxation (TLESR). TLESRs were significantly longer in duration than single swallows (15.1 seconds vs 5.6 seconds, P < .001) and had lower nadir pressures (0.8 mm Hg vs 2.3 mm Hg, P < .001). A total of 3216 esophageal body pressure waves were analyzed; 70% of swallow-induced pressure waves were peristaltic in sequence compared with 5% of swallow-unrelated pressure waves. During periods of esophageal acidification (pH below 4), peristaltic esophageal body pressure wave sequences cleared acid refluxate more effectively than nonperistaltic pressure wave sequences.

Conclusions: In healthy preterm infants, TLESRs are the predominant mechanism underlying GER, and esophageal clearance mechanisms are well developed by at least 31 weeks' postmenstrual age.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cohort Studies
  • Esophagogastric Junction / physiopathology
  • Esophagus / physiology
  • Female
  • Gastric Acid / physiology
  • Gastric Acidity Determination
  • Gastroesophageal Reflux / diagnosis
  • Gastroesophageal Reflux / physiopathology*
  • Humans
  • Infant, Newborn
  • Infant, Premature, Diseases / diagnosis
  • Infant, Premature, Diseases / physiopathology*
  • Male
  • Manometry
  • Peristalsis / physiology