Development of esophageal peristalsis in preterm and term neonates.

Background & Aims: High-resolution manometry demonstrates a chain of 3 sequential pressure segments that represent esophageal peristalsis in children and adults. We performed high-resolution manometry in preterm and term neonates to determine the ontogenesis of esophageal motility with regard to this segmental architecture.
Methods: Sixteen preterm (gestational age 32.9 +/- 2.6 weeks at examination) and 14 term neonates (38.9 +/- 1.6 weeks) underwent manometry with a 9-lumen perfused catheter having recording side holes spaced at 1-cm intervals. Pressure responses to swallows were evaluated for the presence of peristaltic segments on isobaric contour maps by an investigator who was blinded to gestational age.
Results: The second segment was well developed in > or =50% of swallows in all preterm and term neonates. In contrast, the first segment was present in > or =50% of swallows in only 2 preterm neonates (12.5%) and 8 term neonates (57.1%; P < .05 for each compared with second segment) with identical findings for the third segment (12.5% preterm and 57.1% term neonates; P < .05 for each). Completed peristalses with intact segmental contraction sequences throughout the esophageal body were present in 26% +/- 6% of swallows in preterm neonates vs 55% +/- 9% in term neonates (P = .01).
Conclusions: The second pressure segment in the midesophagus (proximal smooth-muscle region) is well developed before term. Presence of other segments significantly improves at term, but peristalsis remains incomplete in nearly half of swallows. Control mechanisms for both striated- and smooth-muscle esophageal regions are incompletely developed in neonates, the outcome of which could participate in infant reflux disease.